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English Pages 544 Year 2023
Handbook of Construction Management for Instrumentation and Controls
Handbook of Construction Management for Instrumentation and Controls K. Srinivasan, T.V. Vasudevan, S. Kannan, and D. Ramesh Kumar
This edition first published 2024 © 2024 John Wiley & Sons Ltd All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, except as permitted by law. Advice on how to obtain permission to reuse material from this title is available at http://www.wiley.com/go/permissions. The right of K. Srinivasan, T.V. Vasudevan, S. Kannan, and D. Ramesh Kumar to be identified as the authors of this work has been asserted in accordance with law. Registered Offices John Wiley & Sons, Inc., 111 River Street, Hoboken, NJ 07030, USA John Wiley & Sons Ltd, The Atrium, Southern Gate, Chichester, West Sussex, PO19 8SQ, UK For details of our global editorial offices, customer services, and more information about Wiley products visit us at www.wiley.com. Wiley also publishes its books in a variety of electronic formats and by print-on-demand. Some content that appears in standard print versions of this book may not be available in other formats. Trademarks: Wiley and the Wiley logo are trademarks or registered trademarks of John Wiley & Sons, Inc. and/or its affiliates in the United States and other countries and may not be used without written permission. All other trademarks are the property of their respective owners. John Wiley & Sons, Inc. is not associated with any product or vendor mentioned in this book. Limit of Liability/Disclaimer of Warranty While the publisher and authors have used their best efforts in preparing this work, they make no representations or warranties with respect to the accuracy or completeness of the contents of this work and specifically disclaim all warranties, including without limitation any implied warranties of merchantability or fitness for a particular purpose. No warranty may be created or extended by sales representatives, written sales materials or promotional statements for this work. This work is sold with the understanding that the publisher is not engaged in rendering professional services. The advice and strategies contained herein may not be suitable for your situation. You should consult with a specialist where appropriate. The fact that an organization, website, or product is referred to in this work as a citation and/or potential source of further information does not mean that the publisher and authors endorse the information or services the organization, website, or product may provide or recommendations it may make. Further, readers should be aware that websites listed in this work may have changed or disappeared between when this work was written and when it is read. Neither the publisher nor authors shall be liable for any loss of profit or any other commercial damages, including but not limited to special, incidental, consequential, or other damages. Library of Congress Cataloging-in-Publication Data Names: Srinivasan, K., editor. | Vasudevan, T.V., editor. | Kannan, S., editor. | Ramesh Kumar, D., editor. Title: Handbook of construction management for instrumentation and controls / edited by K. Srinivasan, T.V. Vasudevan, S. Kannan, and D. Ramesh Kumar. Description: Hoboken, NJ, USA : John Wiley & Sons, Ltd., [2024] | Includes bibliographical references and index. Identifiers: LCCN 2023003580 (print) | LCCN 2023003581 (ebook) | ISBN 9781394195206 (hardback) | ISBN 9781394195213 (ebook) | ISBN 9781394195220 (epub) | ISBN 9781394195237 Subjects: LCSH: Petroleum refineries--Design and construction. | Gas manufacture and works--Design and construction. | Chemical engineering--Instruments. | Factory management. Classification: LCC TH4571 .H36 2024 (print) | LCC TH4571 (ebook) | DDC 658.5--dc23/eng/20230701 LC record available at https://lccn.loc.gov/2023003580 LC ebook record available at https://lccn.loc.gov/2023003581 Cover image: © Siegfried Kaiser/Getty Images Cover design by Wiley Set in 9.5/12.5pt STIXTwoText by Integra Software Services Pvt. Ltd, Pondicherry, India
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Contents About the Authors xvi List of Figures xix List of Tables xxiv List of Forms xxv Preface xxvii Abbreviations xxix
1 1.1 1.2 1.3 1.4 1.4.1 1.4.2 1.4.3
Site Operations Manual – General 1 Introduction to the Handbook 1 Need for Handbook 2 Contract Types and Construction Management 2 Roadmap to Handbook 3 Oil and Gas Industry 3 Codes and Standards 3 Influence of Chemical Plant Nature on Construction 3
2 2.1 2.2 2.2.1 2.2.2 2.2.3 2.2.3.1 2.2.3.2 2.2.4 2.2.4.1 2.2.4.2 2.2.4.3 2.2.4.4 2.2.4.5 2.2.4.6 2.2.4.7 2.2.4.8 2.2.4.9 2.2.4.10 2.2.4.11 2.2.5 2.2.5.1 2.2.5.2
Construction Management – SITE Operations 7 SITE Management and Operations – Overview 7 Site Operations Manual 8 Site Construction Manager 8 Site Mobilisation 9 Site Organisation 9 Size 9 Organisation Structure and Manpower Resources 10 Engineering Administration 11 Engineering Standards On Site 12 Documents to be Available On Site 12 Material Management 12 Tools and Tackles On Site 12 Installation and Commissioning Schedule 12 Detailed Schedules for Installation and Shutdown 12 Clearance Certificates 12 Morning Meetings 13 QA Procedures 13 Safety Policy 14 Installation, Testing and Commissioning 14 Site Safety Practices and Rules 18 General Requirements 18 Administration 22
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2.3 2.3.1 2.3.2 2.3.2.1 2.3.2.2 2.3.2.3 2.3.2.4 2.3.2.5 2.3.3 2.3.3.1 2.3.3.2 2.3.3.3 2.3.3.4 2.3.3.5 2.3.3.6 2.3.3.7 2.3.3.8 2.3.4 2.3.4.1 2.3.4.2 2.3.4.3 2.3.4.4 2.3.4.5 2.3.4.6 2.3.4.7 2.3.5 2.3.5.1 2.3.5.2 2.3.5.3 2.3.5.4 2.3.5.5 2.3.5.6 2.3.5.7 2.3.5.8 2.3.5.9 2.3.5.10 2.3.5.11 2.3.5.12 2.3.5.13 2.3.6 2.3.7 2.3.7.1 2.3.7.2 2.3.7.3 2.3.7.3.1 2.3.7.3.2 2.3.7.3.3 2.3.8 2.3.8.1 2.3.8.2 2.3.8.3 2.3.8.4 2.3.9
Site Administration and Cost Control 40 Plans and Schedules 40 Materials Management and Storage 40 Goods Receipt 40 Goods Issue 41 Spares 41 Software 42 Site Purchase 42 Staff Management 42 Site Organisation Structure 42 Site Working Hours 42 Charge Numbers For Site 43 Applying for Leave 43 Travel for Staff on Site 43 Discipline on Site 43 Performance Review for Staff On Site 43 Staff on Temporary Transfer to Site 43 Site Administration and Cost Control 43 Site Cost Monitoring 43 Site Cost Control 43 Revised Cost Estimates 44 Budget Updates 44 Corrective Action 44 Estimate at Completion (EAC) 44 Lessons Learned 44 Subcontractor Management 44 Subcontractor Check List 45 Obligations to the Subcontractor 45 Subcontractor Supervision 45 Quality in Work 45 Morning Meetings 45 Delays Caused by the Subcontractor 46 Breach of Contract by the Subcontractor 46 Subcontractor Safety 46 Claims by the Subcontractor 46 Progress Payment Claims 46 Delay Claims 46 Extension of Time Claims (EOT) 46 Dealing With the Client 47 Role of the Site Manager 47 Documents and Records On Site 47 Engineering Manuals 47 Engineering Drawings and Database 47 Registers / Files to be Maintained On Site 47 General 47 Contract Related 48 Subcontractor Related 48 Drawings / Documents / Manuals Issued to Subcontractor 48 System Related 48 Software on Site 48 Material Management Related 48 Safety Related 48 Overseas Construction Sites (Middle and Far East) 48
Contents
2.3.10 2.3.10.1 2.3.10.2 2.3.10.3 2.3.10.4 2.3.10.5 2.3.10.6 2.3.11 2.3.11.1 2.3.11.2 2.3.12 2.3.12.1 2.3.12.2 2.4 2.4.1 2.4.2 2.4.2.1 2.4.2.2 2.4.2.3 2.4.2.4 2.4.2.5 2.4.2.6 2.4.2.7 2.4.2.8 2.5 2.5.1 2.5.2 2.5.2.1 2.5.2.2 2.5.2.3 2.5.3 2.5.4 2.5.5 2.5.5.1 2.6 2.6.1 2.6.2 2.6.2.1 2.6.2.2 2.6.2.3 2.6.2.4 2.6.2.5 2.6.2.6 2.6.2.7 2.6.2.8 2.6.2.9 2.6.2.10 2.6.2.11 2.6.2.12 2.6.2.13 2.6.2.14 2.6.2.15 2.6.2.16
Communications and Reporting 49 Language Parlance 49 Types of Communication 49 Fortnightly Events Report 50 MPR and S-Curve 50 SIR and CWR 50 Safety Report 50 Project Completion and Closure 50 Check List for Project Closure 50 Formal Acceptance of Closure 50 PMC / Owner – Roles and Responsibilities 50 Data Sharing 50 Legal 51 Site Work Clearances and Permits 51 Introduction 51 Clearance Requirements 52 Clearance to Work Certificate 52 Types of Permits 52 Work Requiring a Clearance to Work 52 Requesting a Clearance to Work 52 Issuing a Clearance to Work 53 Changes to Scope of Work 53 Authorised Issuers 54 Documentation 54 Planning, Scheduling and Cost Control 54 General 54 Introduction to Planning 54 WBS 54 CPD and CPM 57 Network Planning 58 Introduction to Scheduling (and Use of S-Curve) 61 Introduction to Reporting (Gantt Chart) 62 Introduction to Construction Cost Estimation 67 Overview 67 Technical Spec Tender and Template 72 Introduction 72 Scope of Works and Supply 73 Calibration Works 73 Supply and Installation Works 74 Cabling, Laying and Wiring Works 74 Piping and Tubing Hook-Up Works 74 Earthing Works 74 Loop Check Works 74 Documentation 75 Pre-Commissioning and Commissioning 75 Information From Tenderer 75 Mobilisation and SITE Management 75 Labour Laws and Law Requirements 76 Insurance 77 Contract Unassignable 77 Contractor’s Warranty 77 Contractor’s Guarantee 77 Inspection and Tests 78
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2.6.2.17 2.6.2.18 2.6.2.19 2.6.2.20 2.6.2.21 2.6.2.22 2.6.2.23 2.6.2.24
Confidentiality 78 Contractor’s General Indemnity 78 Arbitration 78 Jurisdiction of Courts 78 Force Majeure 78 Annexure 1 to Section 2.6 78 Annexure 3 to Section 2.6 79 Annexure 4 Tender Schedule of Rates Format 79
3 3.1 3.1.1 3.1.2 3.1.3 3.1.4 3.2 3.2.1 3.2.2 3.2.3 3.2.4 3.2.5 3.3 3.3.1 3.3.1.1 3.3.1.2 3.3.1.3 3.3.1.4 3.3.2 3.3.2.1 3.3.2.2 3.3.2.3 3.3.2.4 3.3.3 3.3.3.1 3.3.3.2 3.3.3.3 3.3.3.3.1 3.3.3.3.2 3.3.3.3.3 3.3.3.3.4 3.3.3.3.5 3.3.3.3.6 3.3.3.3.7 3.3.3.3.8 3.3.3.3.9 3.3.3.3.10 3.3.3.3.11 3.3.3.3.12 3.3.3.3.13 3.3.3.3.14 3.3.3.3.15 3.3.3.3.16 3.3.3.3.17
Site Operations Manual – I&C 81 General 81 Engineering Handover 81 Site Structure for I&C Works Contract 85 Introduction to “Smart Instrumentation” Software 85 Preliminaries and Sequence of Works – I&C 87 Site Estimations and Preparations – I&C 90 Information Compilation 90 Man-Hour Estimate 92 Typical Engineering Cost Estimate Master Sheet 93 Documentation to be Available at Site 95 Tools, Tackles, Test Instruments / Equipment Miscellany 95 Field Installation 96 General 96 Overview 96 Equipment and Manpower Requirements 97 Instrument Mounting Locations 97 Accessibility 98 Field Installation – Instrument Accessories 100 Instrument Stanchion Installation 100 Instrument Sunshade Installation 103 Instrument Tag Plate Installation 106 Field Boxes and Panels Installation 106 Instrumentation Cabling Installation 109 Importance of Specification in Cable Laying 109 Cable Glands Installation 112 Cable Routing, Supporting and Fastening Installations 112 General 112 Cable Signal Segregation 112 Cable Routing Methods 114 Cabling From Field Junction Box to Control Room Marshalling Cabinets 115 Aboveground Cable Supporting System 115 Cable Tray-Ladder and Support Systems 115 Conduit and Conduit Fittings and Supports Installation 117 Cable Fastening 119 Underground Cable Supporting System 119 Computer False Floor 119 Cables in Trenches and/or Ducts 119 Duct Bank System Installation 122 Cable Entry Sealing 123 Cable Termination 123 Noise and Signal Interference Reduction 123 Cable Glands Installation 124 Connections at Field Instruments 124
Contents
3.3.3.3.18 3.3.3.3.19 3.3.3.3.20 3.3.3.3.21 3.3.3.3.22 3.3.3.3.23 3.3.3.3.24 3.3.3.3.25 3.3.4 3.3.4.1 3.3.4.2 3.3.4.3 3.3.4.4 3.3.4.5 3.3.5 3.3.5.1 3.3.5.2 3.3.6 3.3.6.1 3.3.6.2 3.3.7 3.3.7.1 3.3.7.2 3.3.7.3 3.3.7.4 3.3.7.5 3.3.7.6 3.3.7.7 3.3.7.8 3.3.7.9 3.3.7.10 3.3.7.11 3.3.7.12 3.3.7.13 3.3.8 3.3.8.1 3.3.8.2 3.3.8.2.1 3.3.8.2.2 3.3.8.3 3.3.8.3.1 3.3.8.3.2 3.3.8.4 3.3.8.5 3.3.8.6 3.3.8.7 3.3.8.7.1 3.3.8.7.2 3.3.8.7.3 3.3.8.8 3.3.8.8.1 3.3.8.8.2 3.3.8.9
Connections at Field Junction Boxes 124 Termination 125 Identification 126 Cable Supporting – Installation Detail 128 Cable Entry Sealing and Multi-Cable Transits (MCT) Installation 130 Cable End-to-End Installation 132 FF Cabling and Wiring – Special Note 133 Fibre Optic Network Cabling – Special Note 134 Field Instrumentation Earthing Installation 136 Grounding and Earthing Plan 136 Safety Ground Installation 139 Instrument DC and Shield Ground 140 Safety Ground Conductor Connections 140 Ground Fault Detection 140 Field Instrument-to-Process Installation 142 Instrument Impulse Tubing Installation 142 Pipe Manifolds and Direct Mounted Instruments – Installation 145 Online Instruments Installation 146 Pressure Gauges and Pressure Switches 146 Pressure and Differential Pressure Transmitters 147 In-Line Instruments Installation – Flow Meters 150 General Guidelines for Flow Meters 150 Orifice Plate and Flanges and Restriction Orifices 153 Venturi Tubes 154 Flow Nozzle 154 Wedge Flow Meter 154 Vortex Flow Meter 156 Ultrasonic Flow Meter Head 156 Coriolis Flow Meter 157 Electromagnetic (EM) Flow Meters 159 Variable Area Flow Meter (Rotameter) 161 Turbine Flow Meter 162 Positive Displacement or PD Flow Meter 164 Averaging Pitot Tube 165 In-Line instrumentation – Level Instruments on Vessels / Equipment 167 Types 167 General Guidelines For Installation 168 Standpipes / Stilling Well Fabrication Basics 168 Installation Guidelines 169 Level Gauges 169 Tubular / Reflex / Transparent Level Gauge / Indicators Installation 169 Magnetic Level Gauge / Indicators Installation 170 Guided Wave Radar (GWR) 170 Non-Contact Radar Level Transmitter Installation 172 Differential Pressure Level Instruments 174 Displacer Level Instruments 176 LVDT Type Displacer Level Instruments 176 Torque Tube Type Displacer Level Instruments 176 Installation Guidelines 176 Float Type Liquid Level Switches 177 Switch Mechanisms 177 Installation Guidelines 177 Magnetostrictive Level Transmitters 178
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3.3.8.10 3.3.8.11 3.3.8.12 3.3.8.13 3.3.8.14 3.3.8.15 3.3.8.15.1 3.3.8.15.2 3.3.9 3.3.9.1 3.3.9.2 3.3.9.3 3.3.10 3.3.10.1 3.3.10.2 3.3.10.3 3.3.10.3.1 3.3.10.3.2 3.3.10.3.3 3.3.10.4 3.3.10.4.1 3.3.10.4.2 3.3.10.4.3 3.3.10.4.4 3.3.10.4.5 3.3.10.4.6 3.3.10.4.7 3.3.10.4.8 3.3.10.4.9 3.3.10.4.10 3.3.10.4.11 3.3.10.4.12 3.3.10.4.13 3.3.10.4.14 3.3.10.4.15 3.3.10.4.16 3.3.10.4.17 3.3.10.4.18 3.3.10.4.19 3.3.10.4.20 3.3.10.4.21 3.3.10.4.22 3.3.10.4.23 3.3.10.4.24 3.3.10.4.25 3.3.10.4.26 3.3.11 3.3.11.1 3.3.11.2 3.3.11.3 3.3.12 3.3.13 3.3.14
Capacitance Probe 179 Vibrating Fork Level Detector 180 Rotating Paddle Level Detector 182 Radiometric Level Detector 182 Tank Gauging – Manual 184 Automatic Tank Gauging (ATG) 184 Float Gauge–Servo 187 Hybrid Tank Gauging for Redundancy 187 Inline instruments – Temperature Instruments on Lines / Vessels / Equipment 187 General Guidelines for Temperature Measurements 187 Thermowells 188 Bi-Metal Thermometer 189 Process Analysers Installation 190 Introduction 190 Analyser Fundamentals 191 Analyser Installation Basics 201 Introduction to Installation 201 Analyser Enclosures Installation 203 General Sampling System Installation 205 Installation Guidelines 208 pH Analyser 208 Conductivity Analyser 209 Composition Analysis – Chromatographs 209 Oxygen Analyser 210 Sulphur Analyser 210 H2S Analyser 211 H2S – Oxygen Analyser 212 Oxygen Combustibles 212 Distillation Analyser 212 TOC Analyser 213 Oil-in-Water Analyser 213 Hydrogen-in-Gas Analyser 214 In-Line Hydrogen Sensor 214 Viscosity Analyser 214 Densitometer – Liquid 215 Densitometers – Gas and Wobbe Index 216 Moisture and Dew Point Analyser 216 Flash Point Analyser 216 Freeze Point and Cloud Point Analyser 217 RVP Analyser 218 Cold Filter Plug Point (CFPP) 218 Safety Gas Detectors 218 Analyser – Flare Emissions – EPA 220 Analyser – Others – EPA – Water 221 Analyser – CEM Other Than Flare Monitoring 221 AMADAS 225 CV, MOV and PSV 226 Control Valves 226 Motor Operated Valves 229 Safety Valves 231 Instrument Air Piping and Pneumatic Transmission – Installation 233 Instrument Hydraulic Transmission Installation 235 Instrumentation Painting Requirements 237
Contents
3.4 3.4.1 3.4.1.1 3.4.1.2 3.4.2 3.4.2.1 3.4.2.2 3.4.2.3 3.4.3 3.4.4 3.4.4.1 3.4.4.2 3.4.4.2.1 3.4.4.2.2 3.4.4.2.3 3.4.4.2.4 3.4.4.2.5 3.4.4.2.6 3.4.4.2.7 3.5 3.5.1 3.5.2 3.6 3.6.1 3.6.2 3.6.3 3.6.3.1 3.6.3.2 3.6.3.3 3.6.3.4 3.6.3.5 3.6.3.6 3.6.4 3.6.4.1 3.6.4.2 3.6.4.3 3.6.4.4 3.6.4.5 3.6.4.6 3.6.4.7 3.6.4.8 3.6.4.8.1 3.6.4.8.2 3.6.4.8.3 3.6.4.8.4 3.7 3.7.1 3.7.2 3.7.3 3.7.4 3.7.5 3.7.5.1 3.7.5.2
Calibration 237 Introduction 237 Reference Accuracy vs. Bench Accuracy vs. Installed Accuracy 237 Accuracy in Terms of %FS (Full Scale) or % of Reading 238 Method or Procedure Statements 238 Method Statement 238 Guidelines 239 Calibration of HART and SMART Instruments 241 Calibration vs. Functional Test 242 Typical Hook-Ups and Calibration Steps 243 Typical Calibration Hook-Ups 243 Typical Instrument Calibration Steps 244 Pressure Instruments 244 Level Instruments 244 Temperature Instruments 246 Flow Instruments 246 Control Valves and Accessories 247 Safety – Relief Valves 250 Analysers – Calibration 250 Electrical Works For I&C 263 Scope of Works 263 Electrical and I&C Interface Activities 264 Control Room and Automation Works 273 Introduction to Control Room and Building 273 Introduction to System Architecture 274 Control Room (CR) Installation Works 276 Control Room I&C System – Installation Works 276 System Cabinet / Consoles / Workstations / Panel Installation 279 CR Conduit, Cable Tray / Ladder Installation 281 Power Cable, Signal Cable, Fibre Optic Cable Installation 281 Junction Box / FGS Panel Installation 282 FGS and Other Instruments Installation 282 Building Management and Access Control 282 Control Room HVAC 284 FGS for Control Room 287 Access Control 288 Rodent Control 289 Corrosion Monitoring – Control / SIH Rooms 289 Surge Protection Devices (SPD) 290 CCTV System 293 System Interfaces and Cyber Security – OT 294 System Interface Management 294 Cyber Security 295 Sys Interface – Contractor’s Role 295 MODBUS Inter System Links 297 Special Packs 298 Compressor I&C Packages 298 HVAC Systems – I&C 299 Satellite Instrument House (SIH) 300 Wireless I&C Preparations 302 Special Automation Packages 302 Tank Gauging Systems (TGS) 302 Tank Automation Systems (TAS) 303
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3.7.5.3 3.7.5.4 3.7.5.5 3.7.5.6 3.7.6 3.7.7 3.7.7.1 3.7.7.2 3.7.7.3 3.8 3.8.1 3.8.2 3.8.3 3.8.4 3.8.4.1 3.8.4.2 3.8.4.2.1 3.8.4.2.2 3.8.4.2.3 3.8.4.2.4 3.8.5 3.8.6 3.8.7 3.8.7.1 3.8.7.2 3.8.7.3 3.9 3.9.1 3.9.2 3.9.3 3.9.3.1 3.9.3.2 3.9.3.2.1 3.9.3.2.2 3.9.3.2.3 3.9.4 3.9.4.1 3.9.4.2 3.10 3.10.1 3.10.2 3.10.2.1 3.10.3 3.10.4
Product Terminal Systems 304 Meter Prover Systems and Custody Transfers 307 Chemical and Catalyst Loading Systems 309 Variable Speed / Frequency Drive System 310 Emergency Isolation and Depressuring System 310 Special Third-Party Interfaces on Installations 312 IBR (India) 312 Nuclear Third-Party Inspections 313 Fire and Gas Third-Party Interfaces 314 QA/QC Plan – I&C 314 Introduction 314 Typical I&C QA/QC Plan 314 Information and Construction Check List 318 Loop Test 318 Loop Folder 318 Loop Test / Checks 320 Basics of Loop Checks 320 Loop Check Principles 322 Loop Check Methods for 4–20 mA or HART Transmitters 323 Detailed Loop Checks Procedure 324 Site Acceptance Test (SAT) Works 327 Site Integrated Test (SIT) Works 335 Pre-Commissioning Check Lists 335 Activity Log Register 335 Change Management 336 Pre-Commissioning Check List 336 Commissioning Works 338 Integrated Control System Commissioning 338 Plant Commissioning Preparation and Steps 338 Loop Tuning 340 Loop Tuning Basics 340 Loop Tuning – A Brief Introduction 341 Trial and Error Method 341 Open Loop Control Method 341 Closed Loop Control Method 342 Final Commissioned Plant Submissions 342 Final Activities 342 Dossier and Forms 343 Sign-Offs and Handover 346 Final Site Cleaning 346 Punch List – Final for Handover 346 Post Punch Check List for Commissioning 346 HAZOP and PSSR 347 Site Handover After I&C Works 348
4 4.1 4.2 4.3 4.4 4.5 4.6 4.7
Bulk Construction Material Specifications 349 Stanchions / Pipe Stands Specifications 349 Instrument Sunshade Specifications 351 Instrument Tag Plate Specifications 351 Junction Boxes Specifications 352 Cable Gland Specifications 355 Local Control Panel 355 Tubing and Tube Fitting Specifications 357
Contents
4.8 4.9 4.10 4.11 4.12 4.13 4.13.1 4.13.2 4.14 4.15
Valve Manifold Specifications 358 Instrument Cable Specifications 359 Network Cable Specifications 366 Instrument Concrete Duct Bank Specifications 367 Instrument Trays / Ladder Specifications 368 Conduit and Conduit Fitting Specifications 369 Conduits 369 Conduit Fittings 370 Multi-Cable Transit Specifications 370 Earthing / Grounding Material Specifications 371
5 5.1 5.1.1 5.1.2 5.1.3 5.2 5.2.1 5.2.2 5.2.3 5.2.3.1 5.2.3.2 5.2.4 5.2.5 5.2.6 5.2.7 5.2.8 5.2.9 5.2.10 5.2.11 5.2.12 5.2.13 5.2.14 5.2.15 5.2.16 5.2.16.1 5.2.16.2 5.2.16.3 5.2.16.4 5.2.16.5 5.2.16.6 5.2.16.7 5.3 5.4 5.4.1 5.4.2 5.4.3 5.4.4
Engineering Information 373 International Standards List 373 Standards Specific to I&C Construction Phase 373 Standards Specific to I&C Engineering Design 375 Associated Standards Useful to I&C 376 Useful Engineering Information 376 Thermocouple Tables 376 RTD Tables 377 Flange and Gasket Standards 377 Flanges 377 Gaskets 378 Corrosive Environment Class for Control Rooms 379 Hazardous Area Classification 380 Ingress Protection 381 Safety Integrity Limit (SIL) 381 Pressure Definitions 382 Typical Piping Connection Size for Instruments 382 Differential Pressure Level Measurement Suppression Elevation Calculation 383 Selected Engineering Conversions 384 Material Selection Table 387 Commonly Used Elastomers in Gaskets and Seals in Refineries 388 Control Valve Inherent Flow Characteristics 388 Physical Constants of Fluids 389 MODBUS – An Introduction 389 Introduction 389 How is the Data Stored in Standard MODBUS? 389 What is the Server ID? 390 What is a Function Code? 390 Error Checking 390 MODBUS Messages 390 Typical Wiring for MODBUS Communications 390 Typical Sample Drawings / Documents for Construction 392 Software in I&C Construction Management 400 Software Tools in Site Office Management 400 Field Bus Testing and Training Lab 400 Software Trends in Site Management 400 Loss and Profitability in Construction Contracts 400
6 6.1 6.1.1 6.1.1.1
Compendium of Forms 403 General 403 Site Office Personnel Forms Index 403 Employee Weekly Time Sheet Form 404
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6.1.1.2 6.1.1.3 6.1.1.4 6.1.1.5 6.1.1.6 6.1.2 6.1.2.1 6.1.2.2 6.1.2.3 6.1.2.4 6.1.2.5 6.1.2.6 6.1.2.7 6.1.2.8 6.1.2.9 6.1.2.10 6.2 6.2.1 6.2.1.1 6.2.1.2 6.2.1.3 6.2.1.4 6.2.1.5 6.2.1.6 6.2.2 6.2.2.1 6.2.2.2 6.2.2.3 6.2.2.4 6.2.2.5 6.2.3 6.2.3.1 6.2.3.2 6.2.3.3 6.2.3.4 6.2.3.5 6.2.3.6 6.2.3.7 6.2.3.8 6.2.3.9 6.2.3.10 6.2.3.11 6.2.3.12 6.2.3.13 6.2.3.14 6.2.3.15 6.2.3.16 6.2.3.17 6.2.3.18 6.2.4 6.2.4.1 6.2.4.2 6.2.4.3
Employee Requisition Form 405 Travel Request Form 406 Position Specification Form 407 Employee Leave Request Form 408 Employee Expense Report Form – Sheets 1 and 2 409 Site Office Technical Forms Index 411 Customer Work Request Form – CWR 412 Internal Work Request Form – IWR 413 Information Request Form – IR 414 CHANGE Request Form – CR 415 Site Incident and Investigation Report Forms – SIR – Sheets 1 and 2 416 Goods Despatch Register Form – GDR 418 Goods Receipt Register Form – GRR 419 Stores Transaction Register Form – STR 420 SRR and SPIR Forms – Sheets 1 and 2 421 Work Permit and Clearance Forms (WCP) 425 Technical Forms – Typical 436 Trade Skill Test Forms 437 Instrument Fitter 437 Instrument Fabricator 438 Instrument Electrician 439 Instrument Technician (Calibration) 440 Instrument Supervisor 441 Instrument Foreman 442 Calibration Forms 443 Controllers and Receivers – Local 443 Control Valves – Actuators – Calibration and Inspection 444 Field Instrument – General 446 Field / Receiver Switch 447 Analyser Installation and Calibration Check 448 Field Installation Inspection Check Forms 450 Impulse Line Check 450 IA and Pneumatic – Piping System Check 452 IA and Pneumatic – Manifold System Check 454 Junction Box – Local Panel Check 456 Cable Drum Check 458 Cable Installation Check (Instrument and Fiber Optic Cables) 459 Cable Trunking Check 462 Field Cable Termination Check 464 Fieldbus Segment and Extension Check 465 Orifice Plate Check 468 Inline Flow Instrument Check 469 Online Flow Instrument Check 471 Level Instrument Check 472 Temperature Instrument Calibration and Check 474 MOV Installation Check 475 Safety Relief Valves Check 476 Package Instrument Installation Check 478 Analyser Shelter Installation Check 480 Control Room Works 480 Introduction 480 Control Room Requirements 481 Control Room Contracting Trends 481
Contents
6.2.4.4 6.2.5 6.2.5.1 6.2.5.2 6.2.5.3 6.2.5.4 6.2.5.5 6.2.6 6.2.6.1 6.2.6.2 6.2.6.3 6.2.6.4 6.2.6.5 6.2.7 6.2.7.1 6.2.7.2 6.2.7.3 6.2.7.4 6.2.7.5 6.2.7.6
Control Room Installation and Construction Phases 482 Loop Check Forms 484 Analogue Input Loop 484 Analogue Output – Control Valve Loop 485 Digital (Binary) Input Loop 487 Binary Output Loop 488 Motor and VSDS Loop 489 Pre-Commissioning Check Forms 490 Closed Loop Precomm Check Form 490 Open Loop Precomm Check Form 491 BPCS Precomm Check Form 492 Fire Detector Check Form 494 Gas Detector Check Form 495 Commissioning Check Forms 496 Instrument Commissioning Check Sheet – DCS 497 Alarm Action Commissioning Sheet 498 Interlock (Logic) Action Commissioning Check Sheet 499 Trip / Shutdown Action Commissioning Check Sheet 500 DCS Sequence Commissioning Test 501 Authorisation for Process Fluid Let In 502 Index 505
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About the Authors K. Srinivasan Advisor, Mentor and Contributor Main sections contributed: ● ● ● ●
Section 1: Preface and Edits Section 2: Construction Management – Site Operations Section 3: Analysers Overview Section 6: Non-Technical Forms
Educational Qualifications: K. Srinivasan has an Honours degree in Physics, followed by a Post-Graduate diploma in Instrumentation from the Madras Institute of Technology Anna University, Chennai, Tamilnadu (MIT-AU), graduating in 1959. Industrial Experience: K. Srinivasan worked for 23 years with Imperial Chemical Industries (India). During this period he was Group Head on design, maintenance, construction and commissioning of chemical, explosive and fertilizer plant instrumentation. Then he moved to Australia and worked with the Foxboro and Leeds & Northrup companies for 22 years before retirement. During this period, he supervised the implementation of digital computer control in steel, power and cement plants. A pleasing aspect to him during this period was that the company started making profits on their bids. a) Papers Presented: i) Intelligent Automation, at the University of Sydney; ii) Is Advanced Control Relevant Only for Large Plants? at the University of New South Wales; iii) Advanced Control of Distillation Plants, at IIT Chennai. b) Papers Published: A series of articles on Advanced Control of Unit operations. c) Teaching: After retirement, he taught at the TAFE (Technical and Further Education) Sydney for four years on Instrumentation – measurement, installation, testing and commissioning. An extended course on flow meter engineering was given.
About the Authors
T.V. Vasudevan Chief Editor and Contributor Main sections contributed, besides all fill-ins: ● ● ● ● ●
Section 1: Introduction Section 3: Site Operations Manual – I&C (part) Section 4: Bulk Construction Material Specifications (part) Section 5: Appendix – Standards and Engineering Information (part) Section 6: Technical Forms
T.V. Vasudevan has a BSc in Physics followed by a Post-Graduate Diploma in Instrumentation Engineering (DMIT), graduating in 1975 from Madras Institute of Technology, Anna University, Chennai, Tamilnadu (MIT-AU). Now retired, he moderates an online technical forum of Alumni of MIT-AU for I&C engineers. He had served with Engineers India Ltd., New Delhi; Kuwait National Petroleum Co., Kuwait; Stork Comprimo, Singapore; and as I&C Engineer on contract / consultancy in several Middle Eastern and S.E.A. companies. His professional experience is mainly in Design and Detailed Engineering of Oil and Gas, Refinery and Petrochemical Projects, Power plants, Cement plants, Pharmaceutical plants, Sugar plants, etc. D. Ramesh Kumar Contributor – Field Installations Main sections contributed: ● ● ● ● ●
Section 3: Field Installations (part) Section 3: Flow Instrument Installations (part) Section 3: Level Instrument Installations (part) Section 3: Temperature Instrument Installations (part) Section 4: Bulk Construction Material Specifications (part)
D. Ramesh Kumar has a B.Tech in Instrumentation Engineering, graduating in 2001 from Madras Institute of Technology, Anna University, Chennai, Tamilnadu (MIT-AU). Currently, he is with OQ, Oman Oil Refineries and Petroleum Industries Company in Oman as Lead Instrumentation & Control System Engineer. He has over 21 years’ experience in the field from feasibility studies, FEED, detailed engineering, etc. to Project Management, Installation, Commissioning of Oil and Gas, Refinery and Petrochemical Projects. Among other major oil and gas, refinery and petrochemical companies, he worked for are Chennai Petroleum Corporation Limited (CPCL), India; Indian Oil Corporation Limited (IOCL), India; Petroleum Development Oman (PDO), Oman; Saudi Aramco, Saudi Arabia; SABIC, Saudi Arabia, etc. S. Kannan Contributor and Sub-Editor Main sections contributed: ● ● ● ●
Section 2: Instrument Construction Tender Specifications Section 3: Edits & Research: I&C Construction and Site Operations Section 5: Appendix – Standards and Engineering. Information (part) Section 6: Technical forms – Manpower Trade skills, Installation and Calibration, Loop Check, etc. Information
S. Kannan is a BSc (Physics) graduate and has a Post-Graduate Diploma (D.M.I.T) in Instrument Technology from Madras Institute of Technology, Anna University, Chennai,
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About the Authors
Tamilnadu (MIT-AU), graduating in 1976. He has 40 years’ experience in execution of Field Instrument Installation, Precommissioning works and Project Management of various Instrumentation Projects of Refineries, Petrochemicals, Power and Sugar plants, etc. He is associated with Alkan Engineering, Bombay; NRC Engineers (Madras); Sical Yamatake Limited; SABIC, Saudi Arabia; CEGELAC, Abu Dhabi; and BAPCO, Bahrain, and finally retired in 2016. Grateful Acknowledgement to Other Information Contributors T.C. Chandrasekar has a BTech in Instrumentation Engineering, graduating in 1994 from Madras Institute of Technology, Anna University, Chennai, Tamilnadu (MIT-AU). He is currently a Manager (E&I) at M/S Petrofac, Sharjah. ● ● ● ●
Analyser Analyser shelter FAT & SAT Change management
G.R. Omprakash has a BTech in Instrumentation Engineering, graduating in 1993 from Madras Institute of Technology, Anna University, Chennai, Tamilnadu (MIT-AU). He is currently with M/S Deepak Group, Pune, India. ● ●
HVAC Control Room works
V. Satis Kumar is with Instrument Group at NPCC, Abu Dhabi. ●
QA/QC check forms
Thanks to members of MIT Instrument Engineers Alumni (Madras Institute of Technology, Chromepet, AU campus) technical forum (https://groups.google.com/g/itmitians_tech) for specific clarification / information on various topics.
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List of Figures 1.1 1.2 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 2.10 2.11 2.12 2.13 2.14 2.15 2.16 2.17 2.18 2.19 2.20 2.21 2.22 2.23 2.24 2.25 2.26 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12
Hazardous Area Classification map of plant area PERT-CPM / CPD / Gantt definitions Organisation structure – Head Office and SITE Organisation structure – Site Office Personnel Employee Requisition Form CRS or Change Request for Systems Scope Change Worksheet Trade Skill Test – Typical form Incident Report – Typical form Incident Investigation Report – Typical form Work Breakdown Structure – AWBS Work Breakdown Structure – ZWBS Work Breakdown Structure – PWBS CPM network CPM Task Weighted network PERT Chart Gantt chart Network plan S-Curve use S-Curve – Progress S-Curve – Cash S-Curve – Quantity Output S-“Banana” Curve Histogram Typical Project Gantt Chart Typical Critical Path Diagram Cost Estimation Plot Class and Input availability matrix Site Organisation structure for a medium-sized Refinery in India Typical SPI “embedded data” Data sheet Typical SPI “embedded data” Loop Sheet Typical Inspection and Test Plan Typical Instrument Stanchion – for Yoke or surface mounted Instrument Typical Instrument Stanchion – for Multiple Instruments / accessories Typical designs for other Stanchion Mounting possibilities Typical SPI “embedded data” Loop Sheet Typical Field Instrument name-plate JB installation details Cable segregation in paved and unpaved areas Cable crossings – typical
4 5 10 10 11 16 17 27 37 38 55 56 56 57 57 58 58 61 62 63 64 64 65 65 66 66 67 70 85 86 87 88 102 103 104 105 106 107 120 127
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List of Figures
3.13 3.14 3.15 3.16 3.17 3.18 3.19 3.20 3.21 3.22 3.23 3.24 3.25 3.26 3.27 3.28 3.29 3.30 3.31 3.32 3.33 3.34 3.35 3.36 3.37 3.38 3.39 3.40 3.41 3.42 3.43 3.44 3.45 3.46 3.47 3.48 3.49 3.50 3.51 3.52 3.53 3.54 3.55 3.56 3.57 3.58 3.59 3.60 3.61 3.62 3.63 3.64
Cable Ladder Installation Cable Tray Installation MCT Installation Cable from Tray to Inst / JB FF cabling – Field FF cabling – Control room FO network cabling – Distributed vs. Structured Fibre Optic Link and Testing FO – TDR testing FO test check form Field Earthing / Grounding at various locations Manifold valve details Typical Direct PG Mounting Diaphragm assembly for Pressure gauges Pressure and DP installations Draft range transmitter installation Venturi (D–D/2) and Flow Nozzle – as per standards Wedge flow meters Ultrasonic Flow meter Coriolis Flow meter – preferred Orientations Mag Flow meter – Empty Pipe Detection Turbine Flow meter setup Pitot Tube working illustration Averaging Pitot Tube working illustration Air / Gas Pitot array GWR Mount and Level references Radar Antenna Types and Installation Radar Level Dimension considerations in Installation Level DP arrangement Capacitance probe principle Vibrating fork Installation Radiometric Detector Types Tank Gauging – Hand dip ATG – Servo HTG – Hybrid Tank Gauging Thermowell Mounting Sampling system Fast Loop Small Volume Sample Probe Probe for high temperature Water wash Probe Steam Ejector High Pressure Sampling Distillation Column and Volatility Pneumatic system for distillation control sampling pH control Analyser rangeability control Overlap for rangeability control Analyser shelter layout Single Line, Probe and Simple Fast Loop Sample transport types Extractive type gas sampling
129 130 131 132 133 133 134 136 136 137 140 142 145 146 147 149 154 155 156 157 160 162 164 164 166 170 172 173 174 178 180 181 184 185 186 187 190 191 192 192 193 193 195 196 198 198 199 199 203 205 206 206
List of Figures
3.65 3.66 3.67 3.68 3.69 3.70 3.71 3.72 3.73 3.74 3.75 3.76 3.77 3.78 3.79 3.80 3.81 3.82 3.83 3.84 3.85 3.86 3.87 3.88 3.89 3.90 3.91 3.92 3.93 3.94 3.95 3.96 3.97 3.98 3.99 3.100 3.101 3.102 3.103 3.104 3.105 3.106 3.107 3.108 3.109 3.110 3.111 3.112 3.113 3.114 3.115 3.116
pH – flow-through cell Sulphur Analyser UV scheme Viscosity Analyser sampling Freeze and Cloud point graph Freeze and Cloud point Analyser safety Flare Analyser and sampling Dissolved Oxygen Analyser principle High Temperature Oxidation Analyser for TOC CEMS and PEMS Dry Sampling – EMS Wet Sampling – EMS Control valve in the field – with typical hook-ups Control valve piping layouts Control valve drain piping layouts Typical Safety Valve Installation arrangement Multi-Safety Valve Installation guidelines Typical Safety Valve Piping downstream arrangement Inst Air distribution scheme Instrument Air manifold Calibration standard levels Accuracy Full Scale vs % Reading Span and Range – Suppression and Elevation Typical Instrument calibration report Typical Inspection / Calibration Check List Calibration setup for Pressure Transmitters Calibration setup for Temperature Transmitters Level Suppression / Elevation Ranges Control valve calibration setup PST – a typical schematic Safety Valve Test setup Lab Validations for analyser calibration Analyser 2-point calibration setups Chromatogram and Chromatograph Typical Analyser / Detector calibration flow chart Typical E&I Interface and Responsibility matrix Typical Interposing Relay Panel power scheme Typical UPS E–I interface Typical Power supply – SLD–E–I scope in CR Typical Earthing / Grounding – E–I Interface Typical MOV – E–I Interface Typical VSDS – E–I interface Typical IRP and Pump / Machinery – E–I Interface Typical Fire Panel Interface Typical CR console Desk Ergonomics Typical CR console layout concepts Process area and console layout relationship System Architecture – ISA95 model Typical Hierarchical System architecture Typical System Architecture Component Block diagram Control room equipment layout Plan and Index Typical Sample Chiller Utility Information diagram (UID) Typical Duct Instrumentation diagram (DID)
207 210 213 216 216 220 221 221 222 223 223 225 227 229 231 232 233 234 235 236 237 237 239 241 242 242 244 246 248 249 250 252 255 263 264 265 266 267 268 268 269 270 271 273 273 274 274 275 276 282 284 285
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List of Figures
3.117 3.118 3.119 3.120 3.121 3.122 3.123 3.124 3.125 3.126 3.127 3.128 3.129 3.130 3.131 3.132 3.133 3.134 3.135 3.136 3.137 3.138 3.139 3.140 3.141 3.142 3.143 3.144 3.145 3.146 3.147 3.148 3.149 3.150 3.151 3.152 3.153 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 5.1 5.2 5.3 5.4 5.5 5.6
Typical Sample Roof units (DID) ISA chart for Reactive Contaminants classification ISA class G1 air for CR Corrosion monitor for CR Surge Protection Device (SPD) SPD Loop diagram SPD components CCTV Monitor system Simplified System Interfaces and Interconnects Common Cyber and other threats System architecture with Cyber Security protection Secured USB Auxiliary Packs in Control room Compressor Surge control Tank Gauging system Typical SLTS – MLTS ESD system Typical Ship-Shore ESD Link Typical LNG Loading arrangement Meter skid, Bi-directional prover and instrumentation HAZMAT transfer – UN class numbers VSDS – VFDS HIPPS System – minimum requirements HIPPS component schematic. and possible HIPPS in O and G plants Typical IBR Form C Typical Test Handover and Site Acceptance form Loop Folder with Loop Scheme Typical Transmitter Loop Test Scheme Sequence of Acceptance tests per IEC Subsystems for Acceptance tests SAT & SIT Relationship per IEC Typical logic and control block Loop scheme Typical Change Management form Typical Pre-commissioning Check form Open Loop Tuning parameter Motor Check sheet Typical Handover stages and Sign-off documents Post Punch sample list for Commissioning Standpipe / Stanchion Fabrication and BOM specification Stanchion classification Sunshade fabrication Name-plate Valve Manifolds Condensate / Seal pot Instrument cable sections Cable sizes vs. Applications Fiber Optic LAN cable Thermocouple Table RTD table Flange tables Gasket details and tables Hazardous Area Classification Ingress Protection classifications
286 289 289 290 290 291 292 292 293 294 295 296 297 298 302 303 304 305 307 308 309 310 311 312 318 319 320 326 327 328 329 330 336 340 343 344 346 350 350 351 352 359 359 360 362 366 376 377 377 378 380 381
List of Figures
5.7 5.8 5.9 5.10 5.11 5.12 5.13 5.14 5.15 5.16 5.17 5.18 5.19 5.20 5.21 5.22 5.23 5.24 5.25 5.26
Typical layers of Protection and SIL Pressure definition Typical Piping connection sizes Level – DP – Suppression Elevation calculation Selected Engineering Conversion and Data tables Material Selection Table Elastomer table and properties Control valve characteristics Physical constants of some common fluids in Refinery Data Store Protocol in MODBUS Access to Function code in MODBUS Wiring used in MODBUS communication Typical Air Piping layout Typical Cause and Effect diagram Typical CCR console layout Typical Equipment layout – Control room Typical Cable schedule Typical System architecture Typical I/O list headers Typical Functional / Operational Logic diagrams (FLD)
381 382 382 383 384 387 388 388 389 390 390 391 392 393 394 395 396 397 398 399
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List of Tables 1.1 2.1 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 3.20 3.21 3.22 3.23 3.24 3.25 3.26 3.27 3.28 3.29 3.30 3.31 4.1 4.2 4.3 4.4 4.5 5.1 5.2 5.3
Stakeholder Definitions Direct – Indirect – Start-up cost division Contract Documents List Engineering Drawings and Document List Input / Output information Field Installation Quantity information Control Room Works information Controls and Logics Quantity information Man-hour Estimate Construction Cost Estimate form – Field Typical Engineering Cost Estimate form – Control room works Testing Tools and Calibration Instrument Typical Equipment and Manpower requirements Instrument Accessibility Guidelines Typical BOM for Stanchion Cable Colour Coding Cable categorisation FF Field Trunk cabling and marshalling at CR Sampling system conditioning – Liquid & Gas Analysis Hazards General types of analysers used in Refinery Sampling system conditioning – Liquid and Ga Safety Analysers Analyser Types by Calibration / Validation Method BMS Interdisciplinary works table F&G Detector application areas OIML Accuracy Class for Custody Transfers QA/QC and Activity Summary Plan Activity Log Register Inspection Test Control Plan Loop Tuning DS Punch List form HAZOP close-out Report and PSSR (I&C) partial checklist Junction Box data sheet Cable Gland data sheet Ground / Earth wire colour codes Cable and Wire Colour Codes Cable DS I&C Construction Standards I&C Engineering Design Standards I&C Associated Standards
2 68 81 82 90 91 91 91 92 93 94 96 97 99 101 110 113 134 190 200 201 204 218 251 283 287 306 314 314 315 342 345 347 353 356 363 364 365 373 375 376
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List of Forms 6.1 6.2 6.3 6.4 6.5 6.6 6.7 6.7 6.8 6.9 6.10 6.11 6.12 6.13 6.13 6.14 6.15 6.16 6.17 6.18 6.19 6.20 6.21 6.22 6.23 6.24 6.25 6.26 6.27 6.28 6.29 6.30 6.31 6.32 6.33 6.34 6.35 6.36 6.37 6.38 6.39
Site Office Personnel Forms Index Employee Weekly Time Sheet Form Employee Requisition Form Travel Request Form Position Specification Form Leave Request Form Employee Expense Report Form – Sheet 1 Employee Expense Report Form – Sheet 2 Site Office Technical Forms Index Customer Work Request Form – CWR Internal Work Request Form – IWR Information Request Form – IR CHANGE Request Form – CR Site Incident Report Form – SIR – Sheet 1 Site Incident Investigation Report Form – SIR – Sheet 2 Goods Despatch Register Form – GDR Goods Receipt Register Form – GRR Stores Transaction Register Form – STR Stores Purchase Record – SPR Spare Parts List Interchangeability Record – SPIR Clearance to Work and Permit flow chart Clearance to Work Certificate Clearance Log Road Bridge Access Permit Excavation Permit Confined Space Permit Hot Work Permit Crane / Fork Lift Permit High Voltage Isolation Permit Field Instrumentation Permit Instrument Control and Measuring Work permit – ICMWP Technical Forms Index Instrument Fitter (Trade Skill Test) Form Instrument Fabricator (Trade Skill Test) Form Instrument Electrician (Trade Skill Test) Form Instrument (Calibration) Technician (Trade Skill Test) Form Instrument Supervisor (Trade Skill Test) Form Instrument Foreman (Trade Skill Test) Form Controllers and Receivers – Local – Calibration Form Control Valves – Actuators – Calibration and Inspection Form Field Instrument – General – Calibration Form
403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 445 446
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List of Forms
6.40 6.41 6.42 6.43 6.44 6.45 6.46 6.47 6.48 6.49 6.50 6.51 6.52 6.53 6.54 6.55 6.56 6.57 6.58 6.59 6.60 6.61 6.62 6.63 6.64 6.65 6.66 6.67 6.68 6.69 6.70 6.71 6.72 6.73 6.74
Field / Receiver Switch – Calibration Form Analyser – Installation and Calibration Check Forms Impulse Line Check – Field Installation Inspection IA and Pneumatic – Piping System Check – Field Installation Inspection IA and Pneumatic – Manifold System Check – Field Installation Inspection Junction Box – Local Panel Check – Field Installation Inspection Cable Drum Check – Field Installation Inspection Cable Installation Check (Instrument and Fiber Optic Cables) – Field Installation Inspection Cable Trunking Check – Field Installation Inspection Field Cable Termination Check – Field Installation Inspection Fieldbus Segment and Extension Check – Field Installation Inspection Orifice Plate Check – Field Installation Inspection Inline Flow Instrument Check – Field Installation Inspection Online Flow Instrument Check – Field Installation Inspection Level Instrument Check – Field Installation Inspection Temperature Instrument – Field Installation Inspection MOV Installation Check – Field Installation Inspection Safety Relief Valve Check – Field Installation Inspection Package Instrument Installation Check – Field Installation Inspection Analogue Input – Loop Check Form Analogue Output – Control Valve loop – Loop Check Form Digital (Binary) Input loop – Loop Check Form Binary Output loop – Loop Check Form Motor and VSDS Loops – Loop Check Form Closed Loop Precomm Check Form Open Loop Precomm Check Form BPCS – Precomm Check Form Fire Detector Check Form Gas Detector Check Form Instrument – Commissioning Check Form Alarm Action Commissioning Check Sheet Interlock (Logic) Action Commissioning Check Action Sheet Trip / Shutdown Action Commissioning Check Sheet DCS Sequence – Commissioning Check Sheet Authorisation For Process Fluid Let In – Commissioning Check Form
447 449 451 453 455 457 459 462 463 465 467 469 470 472 473 474 476 477 479 485 486 487 488 489 490 491 493 495 496 497 498 499 500 501 503
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Preface Instrumentation for process industries is evolving, perhaps faster than most other technologies. The accuracy and speed at which plant data is made available to personnel is way ahead of what it was, even a decade back. The advent of digital technology and advances made in communication have enabled a revolution. Together with associated computers, relevant reports giving details on current production levels, bottlenecks, raw material stocks, finished goods levels, etc. are made available to board members and production executives, enabling them to take appropriate decisions almost on a real-time basis. Yet, all this depends on one key factor – correct installation and commissioning of the instrumentation system. It is also essential to ensure long-term reliability without frequent breakdowns. For example, any form of analysis instrument, sophisticated or otherwise, is only as effective as its sampling system. Digital technology and today’s communication capabilities have forced changes in office organization structures and office management. Similar changes will start happening in construction management. Traditional management structures, with managers using methods and styles based on their previous experiences at other sites, may be found to be inadequate. In addition, installation, calibration and testing of today’s instruments call for different skills and experiences. Experience in installation and testing are not the only skills needed from a site Instrument Installation Manager, whose job calls for man-power planning, recruitment, site safety, attendance in meetings, progress reporting, material management, cost control, change management, database management, delay management, E.O.T. (Extension-Of-Time for reaching completion), managing government regulations / forms and a host of other issues. Against this background, we come up with a new set of qualifications needed for a site Instrument Installation Manager. Addressing the above needs, this Handbook provides information on all aspects of site management together with details on the traditional installation, calibration and testing of instruments. 1) Section 1 provides a short Introduction and a roadmap to the Handbook. 2) Section 2 on “Construction Management” summarises a list of actions to be performed by the site Instrument Installation Manager. It deals with site administration and control, documentation management and cost control. This section also covers sub-contractor management, breach of contract, progress payments, delay claims, extension of time, documentation, site safety reports, and project completion and closeout. Site incidence reporting system is introduced. 3) Section 3 discusses details of field installation and provides recommendations on installation of pipes, cables, junction boxes, termination, fibre optic networking, grounding, earthing plans, etc. Impulse line connections to different type of services are discussed. Process analyser installations for different duties are given. Details on the calibration of various types of instruments, including HART & Smart instruments are given. Control room I&C systems and building management systems and installations are discussed. Also provided are details on special packs such as – Compressor I&C packages, HVAC systems, Tank automation, Product Terminal systems, Meter-proving and custody transfer and VSD. QA/QC plans are also discussed. Included in this section are Loop check procedures (procedures to be followed for analogue and digital signals). Site Acceptance Tests (SAT), pre-commissioning checks, etc. are described. Guidelines for basic loop tuning are given. Sign-off and handover procedures are discussed. With change management, even after a detailed design effort, some oversight during design stages may lead to the requirement of additional instrumentation. It is not uncommon that during commissioning stages, such additional requirements may be highlighted. While some of the changes could be minor, others may not be so. All changes require time and personnel to handle them. Changes may also lead to further purchasing. In addition, while changes are being
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Preface
executed, associated documentation will need to be upgraded. These lead to additional costs. This Handbook provides procedures for handling change management and associated costing. 4) Section 4 discusses Bulk Construction Materials. From time to time, some items like sunshades, stanchions and nameplates may need to be manufactured or procured for site use. Drawings and specifications for some common items is given here. Specifications for cables are also given. 5) Section 5 is an Engineering Information compilation useful for I&C construction (really an Appendix of Information) that provides a list of standards generally referenced. Also, it has useful engineering standards for thermocouples. An RTD table is provided. Flange and Gaskets standards are provided. Information on Hazardous area classification and Safety Integrity Limits (SIL) are also provided. 6) Section 6 is a Compendium of Forms. Site work essentially moves by approvals, witnesses and authorisations. Entries require authorisation, work on site will need to be permitted, test procedures will need to be authorised, and test results will need to be approved. So, the importance of documentation cannot be over-emphasised. This book has been written by engineers with extensive field experience in installation and commissioning. As such, recommendations made, procedures suggested and tabular forms provided are based on actual practical field experience, rarely, if at all, seen in contemporary literature. After a satisfactory completion of testing, the plant is ready for commissioning. And commissioning is bringing on “stream” a process plant for production. This job is handled by the commissioning team who have a knowledge of all process operations. Though the job of Instrument Installation is complete by this stage, a small team from the installation group is usually retained to assist the commissioning team. K. Srinivasan
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Abbreviations Technical Abbreviations Abbreviations
Description
AWG BPCS BOM C&E CEM DCS EPA ESD FAT FBD HMI /MMI HMT /HMTD HW or H/W ICS I/O MC MTO PAS PC PLC SAT SIS SIT SW or S/W QMI
American Wire Gauge Basic Process Control System Bill Of Material Cause and Effect Diagram Continuous Environmental Monitoring Distributed Control System Environmental Pollution Act Emergency Shutdown System Factory Acceptance Test Functional Block Diagram Human Machine Interface / Man Machine Interface Heat & Mass Transfer (D – Department) Hardware Integrated Control System Input / Output Mechanical Completion Material Take Off Process Automation System Personal Computer Programmable Logic Controller Site Acceptance Test Safety Instrumented System Site Integration Test Software Quality Monitoring Instruments / Quality Measurement Instrumentation
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Abbreviations
Non-Technical Abbreviations Abbreviations
Description
BOT CBA CM CPD CPM CWR DE EPC EPCC FEED GANTT IWR NIST NPL MIV MAC MSDS PMC PPE RFP RFQ RFI SCW SIR TBA TQ UV WHS / WH&S /WHS & R JSA WBS
Build Operate Transfer Commercial Bid Analysis Construction Management Critical Path Diagram Critical Path Method Customer Work Request (form) Detailed Engineering Engineering Procurement Construction Engineering Procurement Construction Commissioning Front End Engineering Design Generalized Activity Normalization Time Table Internal Work List National Institute of Standards & Technology National Physical Laboratory Main Instrument Vendor Main Automation Contractor Material Safety Data Sheets Project Management Consultant Personnel Protective Equipment Request For Procurement / Purchase Request For Quotation Request For Information / Inspection Site Change Work (sheet) Site Incident Report Technical Bid Analysis Technical Queries Ultra Violet Workplace, Health (&) Safety and Rehabilitation Job Safety Analysis Work Breakdown Structure
1
1 Site Operations Manual – General 1.1 Introduction to the Handbook Construction Management (CM) is a professional service that uses specialised Project Management techniques to oversee the planning construction of a project. This Handbook deals with Project Management as applicable to Construction Management of Instrumentation and Control (I&C). There are a variety of plants in operation: Chemical, Petro-chemical, Power, Paper, etc. Some of them are continuously operating plants and some others are batch operating. Construction may be required for mega-sized plants, for small plants or for expansion of existing plants. This Handbook provides guidelines, tools and techniques for the completion of installation and testing of I&C systems to be ready in time for plant commissioning. Construction Management of small- and medium-sized plants is relatively less challenging compared to the mega projects. However, it has been observed that even these projects often run way over budget, defy timeline constraints, present numerous surprises and even lead to lawsuits. In all cases, attention to detail, documenting and highlighting the impact on project schedule and cost, particularly when changes are being proposed, is essential. An early warning of impending overruns is also essential to enable the management to take appropriate actions. This Handbook provides suitable documents to handle change management. Construction Management of I&C differs in detail from one Process Plant to another. This edition specifically covers the Onshore Oil and Gas Industry and mostly Refineries. In some ways, Construction Management is one of the purest forms of Project Management, especially since it shares many of the basic Project Management steps. While forces beyond your control can cause budgets to skyrocket, in most cases, cost over-run is a result of inaccurate estimates, poor installation and lack of co-ordination with other Contractors, poor budget management and lack of visibility into project costs. Cost over-runs are easier to prevent than to resolve later. Construction work starts after the completion of the design phase and a Contractor has been awarded the Instrument construction work. This Handbook is a reference manual to the Contractor right from the start of their job. It deals with resource planning, recruitment, health and safety, cable laying, Control room installation work, testing, pre-commissioning tests, documentation, database management and site meetings reporting, etc., among other things. This Handbook provides a number of typical forms for recording data. It also discusses procedures to handle “additional engineering work” and costing for it. Scope creep is one of the leading causes of project cost over-runs. The Contractor plans for one set of deliverables but, over time, the Client starts asking for “things” that were not originally planned for. Some changes might be called for, but drastic scope creep can put a construction budget in jeopardy. Billable hours can quickly mount up and the project budget will be out of control before the contractor realises it. Fighting scope creep is a constant challenge for Project Managers. This Handbook discusses ways to handle “site variations”. This Handbook provides tables, illustrations and figures to indicate the way things are typically done. Contractors and users may have to engineer them to suit their applications. This Handbook will also be useful as a source book for new engineers intending to take up Construction as a profession.
Handbook of Construction Management for Instrumentation and Controls, First Edition. K. Srinivasan, T.V. Vasudevan, S. Kannan, and D. Ramesh Kumar. © 2024 John Wiley & Sons Ltd. Published 2024 by John Wiley & Sons Ltd.
2
1 Site Operations Manual – General
1.2 Need for Handbook The construction of an industrial process plant project requires many gradual design steps such as feasibility engineering study, basic flow engineering design, front end engineering, detailed engineering, procurement engineering, etc., followed by construction engineering and finally commissioning engineering activities, before a plant is up and running. As an example, for the Oil and Gas Industry, planning a project is based on market resources sometimes controlled directly or indirectly by governments. The deliverability of a project depends on precise planning, scheduling and “flow efficiency” between a very large number of multi-disciplinary activities, which are controlled in a complex sequence of activities from the start (i.e., Feasibility Engineering) to finish (i.e., Commissioning Engineering). All of the above depend on years of evolution of methods and practices. The collective experience of many over the years has now evolved into a great professional career by themselves in the field and hence the need for a Handbook. This Handbook is prepared from the perspective of a Construction Contractor.
1.3 Contract Types and Construction Management Industries have been adopting different contracting approaches leading to construction of chemical plants (also termed as the Process Industry), typically, Cost-reimbursable, Fixed price, Lump sum, Turn-key, Build Operate Transfer (BOT), Costplus, Cost-plus fixed fee, Cost-plus-incentive fee based on Cost percentage, Joint venture, Sub-contract, etc., all of which are legally vetted too. This Handbook concerns itself only with Construction Management specific to I&C. In the Chemical Process Industry, often the plant’s intellectual and design rights are vested in a Process Licensor, and a licensor fee for knowhow and an engineering fee will be add-ons, if applicable, usually taken care of by the Client under the feasibility stage but sometimes added in later. Typical Contract Management follows the following sequence: ● ● ● ● ● ●
Bidder Prequalification Request for Quotes (RFQ) Request for Procurement (RFP) – in lots or by disciplines Technical Query (TQ) to bidders for RFQ/RFP Technical and Commercial bid evaluation and recommendations Award of contracts and mobilisation finalisation.
However, in the Process Plant Industry and specific to I&C systems, other terms, EPC/EPCC (E-Engineering, P-Procurement, C-Construction, C-Commissioning), MIV/MAC (Main Instrument Vendor / Main Automation Contractor), Novated Contractor (in a loop-within-loop contract, slightly modified from the sub-contract), etc., are used further to define engineering services and functionality, mainly for the “non-management” engineers, to identify their responsibilities within a complex contract. Accordingly, the stakeholder / contract definitions in the industry are as in Table 1.1. Table 1.1 Stakeholder Definitions. Definitions
Description
Owner, Customer, Client, Owning Company
All referring to the same entity or a company that owns the plant & facilities; and on whose behalf a contract is issued to build a facility with material & services and is the Primary stake holder
Contractor
Company or organisation entrusted with a contract award to carry out supply of materials & services towards completion of a milestone or milestones for operation & production from plant
Sub-contractor
Company or Organisation contracted & managed by the Contractor
Project Management Consultant (PMC)
Consultant to Owner / Owning Company for Project Management Services
Vendor
Supplier of the Equipment under a specification
Construction contractor
For the context in this book, it refers to Construction Contractor for I&C
EPC/EPIC contractor
For the context in this book, Engineering Procurement (Inspection) Construction Contractor for I&C
EPCC/EPICC contractor
For the context in this book, Engineering Procurement Inspection Construction Commissioning Contractor for I&C
Novated contractor
Replacement of a new contractor from a legitimate existing contractor with a new or old contract, where the transfer is mutually agreed by both parties concerned
1.4 Roadmap to Handbook
The pre-selection criteria before RFQ and selection criteria after RFQ are based on Technical Bid Analysis (TBA) and Commercial Bid Analysis (CBA) in whole or in part and separated for different stages of the project. For example, MAC or PMC contracts may be decided by the Owner at the FEED stage and MIV decided at the Detailed Engineering Stage (DE) based on the Owner’s in-house experience on such matters. The EPCC model is dealt with in this Handbook. Control systems choice – Integrated Control and Safety System (ICS) or Discrete Standalone Systems (DCS, SIS, etc.) and System Architecture and Interfacing required, etc., – lead to some decisions on type of contract complexity.
1.4 Roadmap to Handbook 1.4.1 Oil and Gas Industry Most of the ground rules of Construction Management generalities are common to all industrial process plants and are generalised in this chapter. Operations specific to Construction of I&C is dealt with in Chapter 3. However, there are nuances in Construction Management specific to different Process Plants, as in Oil and Gas exploration (Onshore / Offshore), Refineries and Petrochemicals, Power Plants, etc. This book focuses on Refinery – Oil and Gas. Also, since environmental considerations play a great part, some definitions may vary from common-place use. For example, outdoor locations correspond to wet or damp locations and indoor locations correspond to dry locations. A structure enclosed by walls on three sides only, and with a roof, is considered an outdoor location. A non-air-conditioned building is considered an indoor location. However, a packing and freight area that has to keep its doors open to facilitate entry of vehicles is considered an indoor location.
1.4.2 Codes and Standards Construction in Process Plants needs to follow local codes, rules and regulations in standards. They vary widely from country to country. Specific global engineering requirements follow the international standards and laws. This Handbook will generally follow the International Electrotechnical Commission (IEC) standards. The International Standards Organisation (ISO) will be the alternative standard for safety regarding construction machines / equipment. For local regulatory or mandatory codes, the Handbook provides a generic heading to understand the requirements to be followed. The local codes always take precedence over international regulatory codes.
1.4.3 Influence of Chemical Plant Nature on Construction a) Material management Construction in Process Plants (unlike in basic Civil or Mechanical Construction, say a Mechanical Industrial complex) require wide chemicals management in all aspects from construction to commissioning. But knowledge of the applications to which all civil, mechanical, electrical, etc., are exposed to finally manage chemicals pertains to the type of plant. It is inbuilt into Construction Management as in Material-of-Construction (MOC) management, etc. A corrosive environment is a factor too in determining MOC, and in other areas as well. Severe corrosive environments include: a) Outdoor offshore locations, and b) Outdoor onshore locations within 3 km from the shoreline. b) Electrically Hazardous Area An Electrical Hazardous Area is part and parcel of Process Plant Engineering from start to finish. A hazardous area is “a space in which a flammable atmosphere may be expected to be present at such frequencies as to require special precautions for the control of potential ignition sources including fixed electrical equipment”. Control of such ignitions is by following a risk-based set of national and international codes and regulations. Recognition of hazardous areas follows three important attributes such as likelihood, grade of release and fluid category based on ignition properties. Potential for fire and protection thereof is by limiting energies, isolation / seclusion, enclosures, etc. Figure 1.1 shows typical mapping of a hazardous area that plays an important part in the selection of Instrumentation suitable for that area, classified based on the location of the Instrument in the map and its distance from the possible point of hazardous gas release by accident or mal-operation. Chemical fire management, in combination with other fires such as electrically-induced fires, is a separate engineering in itself. Safety engineering, including safety shutdowns, chemical detection (gas especially) and fire detectors, are an integral part of I&C engineering and therefore of construction. Fire and gas protection is a necessary safety engineering.
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Horizontal section
1.5 m 1.5 m Pressure above
8
1.5 m 1.5 m
Air lock Ventilating duct 3 m Pressure above
Escape location
3m
Suffiently ventilated
Opening (door) Zone 1
Self-closing door
Zone 2
Unclassified
Figure 1.1 Hazardous Area Classification map of plant area (source: Standard IP15, Institute of Petroleum, Part 15 – Area Classification code for Petroleum Installations).
The occupational health and safety of all during construction is always part of any Construction Management, more so in process plants, where multi-disciplinary work is carried out based on work fronts and independent of each other. Regulations followed are common to most construction industries but environmental / specific process safety requirements are part of process plants according to the type of chemicals involved. For example, plants that use flammable utilities like hydrogen or keeping the state of the fluid in vapour form by heat tracing or for geographical conditions such as winterising requirements are factors that play a significant part in Construction Engineering. c) Plant complexity Plant structures vary with type of plant. If the final product is a solid, as in cement plants or PVC in petrochemicals, it would be housed in buildings. Generally, in Refineries, a downstream / upstream concept is followed for locating plant units, in a linear fashion or in a looped square formation if area is at a premium, based on well-established chemical engineering plant design principles. However, safety also defines the separations of plant units. But it is a given axiom that a good plot plan saves cost and time in plant material and construction.
1.4 Roadmap to Handbook
d) Industrial Process Plants need a large multi-discipline group involvement ● Process or Chemical Engineering (design of process, process equipment, etc.) ● Civil Engineering: civil foundations and buildings structures (an example of special interest for this Handbook is the Control Room) ● Structural Engineering (for pipe racks, vessel structures, flare column, etc.) ● Mechanical Engineering of all hues from piping engineering, rotating equipment engineering, static equipment (vessels, columns, etc.) engineering ● Heat and Mass Transfer Engineering (HMT) such as fired heaters, flares, heat exchangers, insulation (hot and cold), refractory, etc. ● Electrical and Electronics Engineering ● Control System Engineering ● Telecommunication Engineering ● Information Technology ● Fire and Safety ● Planning Scheduling and Costing Engineering ● Security Engineering (Access control, Cyber Security, etc.) ● Occupational Safety Health Administration (OSHA) / Workplace, Health, Safety and Rehabilitation (WHS7R) ● Several trades within each engineering with cross discipline experiences with instrumentation. e) Planning and scheduling complexities Understanding the complex sequence of activities in Construction Engineering in process plants is of utmost importance. It is a multi-disciplinary environment and it lays out the work-front available to the Contractor to complete the jigsaw puzzle of works related to a goal. Essential to its management is Planning, Scheduling and Costing Engineering. Several algorithmic software (the most popular being Primavera) are available to do the same. The most common methods widely used are PERT, CPM/CPD and Gantt charts – a brief introduction to them is given in Figure 1.2. Taken together, they form the backbone of planning and scheduling of a large or small project. A base line schedule and current schedule together are required to monitor progress, bring correction to unexpected events or activities or recover from delays. Installation and testing of Instruments always comes towards the end of the project construction activities, by which time other works like Civil, Structural, Piping and Electrical have nearly been completed. For this reason, Instrumentation work always falls on the critical path and pressures to complete the work will be high. Delays are not tolerated. f) Project costing complexities Project costing of many types are performed by another software to do Analogous Estimation, Parametric Estimation, Bottom-Up Estimation, Three-Point Estimation, etc., techniques of cost control or a combination of such techniques. The cost estimation includes and involves material, labour, resource availability and time. There are many ways to compute project costing and the same is applied to construction costing: a) Capital costs (by quotes for equipment); b) Capital costs (by estimation on unit rates); c) Site engineering costs (by man hours); d) Installation costs (by factoring on unit rates from tenders); and e) Commissioning (man hour estimation or lump sum from the Process Licensor) and allowing for Contingencies (as a percentage of subtotal cost). Whatever the nature of the project planning, costing and scheduling mechanisms and delays in I&C construction costs the Owner and / or the Contractor in project completion. With the ramp-up delayed, cash flow will be affected.
PERT - Project Evaluation and Review Technique – is an event driven planning tool and where sequence is established but time for activity may be unknown; & probability math driven.
CPM/CPD - Critical Path Method / Critical Path Diagram – is a time driven activity planning tool where time for a group of activity is known so that it can tell the largest time required in a path of activities. CPM is accepted as a legal basis for measuring project delays & consequent financial claims in courts.
Figure 1.2 PERT-CPM / CPD / Gantt definitions.
A GANTT chart is a graphical depiction of a project schedule & is evolved out of CPM database. It is a type of bar chart that shows the start and finish dates of several elements of a project that include resources, milestones, tasks, and dependencies.
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This in turn leads to increased interest payments on loans and also delays depreciation and amortisation. Another reason could be that with delays in product manufacture the owner might lose an edge over a competitor releasing a similar product. There are basically three effects of delay: time over-run, cost over-run and, in the worst-case scenario, abandonment of the project itself! The Construction Management and / or Contractor can claim an extension of time and increased cost on account of improper planning and scheduling when they are not the cause of any delays and / or delays were out of their control. But the contract can then move into contract term interpretations and legalities of proof, which is undesirable to all stakeholders. g) Objectives of this Handbook The vision of this Handbook is to present a road map to address and understand the basics of technical and technocommercial knowledge involved in proper Construction Management of I&C systems by addressing various guidelines and complexities involved in depth. It addresses methods to avoid delay errors by ignorance of basics and integrate a proper change management plan such that a proactive approach can be adopted involving all stakeholders in the successful completion of I&C works, preparatory to plant start-up and run.
7
2 Construction Management – SITE Operations 2.1 SITE Management and Operations – Overview The word “SITE” is a short form for Project Site but refers not only to the construction area work site but also includes in its bubble-of-access a number of auxiliary offline work areas and offices which are required for successful Construction Management, avoiding waste of time and resources. SITE Management (of activities) for Instrument and Control (I&C) is responsible for the Installation as well as Commissioning of instruments and systems. Many factors make the SITE a key centre in a project. All the efforts of the Designers, Subcontractors and Consultants find their moment of truth on site. SITE personnel, be they from large or small companies, or Subcontractors, operate day in and day out in front of the Client. Hence, they are under the watchful eyes of many parties to the Contract and Client. Being the nerve centre for high activity, the risk of accidents is high, as many other high disciplinary activities are ongoing at the same time. The SITE is one of the big centres. A successful SITE operation will open the door for further opportunities for the Owner and others. A failed one drives the last nail. Every care taken to establish a good SITE establishment is well worth the effort. A well-monitored and controlled SITE not only saves in project costs but also has the potential to pick up a number of opportunities for additional engineering work. In order to establish a good SITE office, the Contractor has to be clear in their mind on how they want their SITEs to function. This Handbook attempts to establish sets of guidelines and procedures for a SITE and SITE office. Works done in earlier projects, wherever available, have been collected, suitably modified and added in this manual. Accurate and timely reporting is essential for an efficient control of project functions. The Handbook offers a number of forms and spreadsheets for this purpose. It is envisaged that various forms and spreadsheets used on projects will be standardised and linked so that the Project Manager quickly gets the status of the project without having to work for hours linking up the various spreadsheets. It is hoped that, with experience, engineers will fine-tune the procedures suggested in this Handbook to meet the changing demands of the times and industries they serve. The reality check on risks with the Construction Industry Business is increased project penalties, shorter delivery cycles and more demanding Clients – these are the challenges in Construction Management today. To succeed and grow, one has to think outside the box. Engineers have to find ways of lowering total Installation costs at reduced levels of risk for their projects. This is best accomplished by analysing the key areas of project activities with a view to establishing costeffective ways of doing them and yet meet the requirements of the Contract. Faced with competition, projects are awarded with very narrow margins. In a number of cases, SITE cost differences are equal to the difference in project bid prices. Different Installation and Commissioning approaches result in different costs. To add to this, very often Instrumentation jobs fall on a “critical path” to completion, for terminating the assigned contract works. Failing to meet the dates attracts penalties. As a result, Site Managers accelerate the schedule to drive the costs down. Against this background, Construction Companies have to be always on the lookout for variations, claims and bonuses to augment the business profits or offset unforeseen losses. If SITE Management is not attentive, heavy losses may occur on account of this. At the same time, the SITE Management cannot lose sight attentive of other key issues such as safety, quality, timely completion, the environmental issues and documentation.
Handbook of Construction Management for Instrumentation and Controls, First Edition. K. Srinivasan, T.V. Vasudevan, S. Kannan, and D. Ramesh Kumar. © 2024 John Wiley & Sons Ltd. Published 2024 by John Wiley & Sons Ltd.
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2 Construction Management – SITE Operations
SITE Management involves the management of the following: 1) 2) 3) 4) 5) 6) 7) 8) 9) 10) 11) 12) 13) 14) 15) 16) 17) 18) 19) 20)
SITE mobilisation SITE organisation Activity sequence Resource planning SITE work clearances and permits Plans and schedules for construction milestones Staff management Materials management Occupational Health and Safety SITE administration and cost control Material supply, reconciliation and spare part management Engineering administration Subcontractor management Dealing with the Client Installation, testing and commissioning Reporting Records Project completion Demobilisation Close out with Management Meeting.
Note: “SITE” and Site mean the same throughout this Handbook, as defined in the beginning of this chapter – SITE is used for emphasis.
2.2 Site Operations Manual SITE Operations and Management can now be looked at in more detail.
2.2.1 Site Construction Manager At this point, it would be good to define the person in charge of Site Management, the Site Construction Manager, and his role. The Site Manager (as the person is noted for short) is responsible for all construction activities to the Contractor Company they serve. He is also the Head of Operations at the site. This is normally a senior position. He reports to the Project Manager. He operates from the SITE. and is mostly responsible for all activities on that site: ●
●
●
● ●
● ● ● ●
He receives: a) all documentation for Installation and Pre-Commissioning (and commissioning too if such assistance also is called for, in the construction contact; b) dates for completion and handover of plant sections; c) ordered items: instruments, accessories; and d) spares, etc. The Site Manager can recruit site Personnel (after obtaining necessary approvals) staff, technicians, engineers, safety and security related personnel, etc. He is responsible for safety at the site. All incidents are to be properly documented. They may be scrutinised by government authorities. Entry into the site will be authorised by the SITE Manager He provides a cost estimate for Installation, Commissioning (in case this assistance is called for) and Handover – this includes: a) man hours cost; b) materials cost – including piping, cables, fittings, etc. (part of it may have been ordered by the Design Department); c) testing and calibrating equipment; d) transport costs; e) services on site; and f) Subcontractors for supply of labour, etc. He is the one-point contact for the Owner on all matters He attends site meetings with the Client He attends Project Review Meetings along with Project Manager Authorises all payments
2.2 Site Operations Manual ● ● ● ●
●
● ●
Authorises all site purchases Responsible for meeting site estimates at the end of the site work Responsible for providing commissioning assistance as requested after costs for it have been approved Responsible for documentation updates (both digital and hard copy formats) as construction and commissioning progresses As changes occur at the site (they usually do occur), the software and drawings are updated quickly so as to be ready well before commissioning. The Master Database is also to be updated simultaneously Responsible for meeting site cost estimates. Provide a report on reasons for over runs if they occur Responsible for site discipline.
2.2.2 Site Mobilisation Mobilisation refers to the movement of teams of men and material required for Construction Management. a) Site-Planning document A site-planning document is essential before start of mobilisation to the site. The plan should contain details such as: ●
● ● ● ● ● ● ● ● ●
Number of people expected on site, including administrative if any (if expected to increase over a period of time, give details) Facilities required on site (office space, phones, fax machines, photocopiers, furniture, etc.) Mobilisation and demobilisation of people as per overall initial project schedule and subsequent changes if any Transport facilities needed Subcontractor details and requirements for them Accommodation details and plans for visitors including vendors Site store details Safety requirements and costs due to them The cost of establishing and maintaining a site office should be worked out and indicated A graph comparing the estimated cost to that allowed in the Contract should be indicated.
The site-planning document needs approval of the Overall Project manager. Too early mobilisation of troops at the site will increase site costs. At the same time, too late a mobilisation may lead to serious delays in the project. b) Site resources mobilisation Usually, this is activity driven but when mechanical resources are shared for large construction equipment or one-offequipment need to be hired for use such as when a heavy-duty lift crane (usually used for Column lift) is required for I&C works, a mobilisation plan and the application request for mobilisation and to the Crane movement controlling authority should be made in advance. A mobilisation plan for special equipment is also planned.
2.2.3 Site Organisation 2.2.3.1 Size
Size of the Site organisation depends on the size and the needs of the project. It should be close to what has been estimated at the time of bidding for the job. Careful planning of the site operations goes a long way in deciding its success. Planning involves such details as: the site organisation and reporting structure; identifying the type of resources needed for the site; the selection of the right kind of people to go to the site; the location of the site office; laying down the site procedures; scheduling activities; safety management; cost monitoring and control procedures; etc. This planning should start right at the time of bidding for the project. To assume that the site can be managed by borrowing engineers from the Design Office is really looking for trouble. Very often, Design engineers do not prove to be good Site engineers. While the need for careful site planning for each project can hardly be over-emphasised, a few guidelines are given in this Handbook. Small projects (up to $500K) in advanced countries within the Metropolitan area may be managed without any site establishment. However, generally all larger projects requiring site establishment will need resource planning for the site. While the numbers might vary depending on the size of the project, the basic requirements will remain the same.
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2.2.3.2 Organisation Structure and Manpower Resources
a) Structure Typical organisation structure samples are given in Figures 2.1 and 2.2. The Site Manager may have a Site Superintendent to assist him. b) Manpower Resource planning Whenever there is a requirement for additional resources on site, it is usually requested at short notice. It would be almost impossible for Project Manager / Head Office to meet these requirements in the absence of planning. In a number of cases, these are done at enormous project costs. Invariably, the compromise consists in sending whoever is available at the time, even if they are not the right kind or have the right skill needed for the job c) Weekly review of manpower It is imperative that the site staff and Manager make a weekly review on manpower requirements. This review should also cover, in addition to the Contractor Company’s direct employees, others such as temporary staff, Contract staff and Subcontractors’ staff. At least a six weeks’ notice should be given to search for and organise additional resources d) Additional manpower requests A spreadsheet that can be used for estimating manpower required on site is attached in Chapter 6. Recruitment of staff, over and above the approved manpower list for the Contract, may need approval unless, as stated earlier, pre-ordained within the SITE Manager’s ambit. SITE Manager can request the recruitment of: a) Casual Staff b) Contract Staff only. Usually, all such recruitment is preceded or initiated by the discipline heads at the site in an “Employee Requisition form” and authorised by the SITE Manager, while simultaneously forwarding to Head Office (Figure 2.3). CONSTRUCTION SITE
HEAD OFFICE
CONSTRUCTION MANAGER / SITE MANAGER
Owner / President /Senior Projects Manager -
ENGINEERING MANAGER VARIOUS DISCIPLINE HEADS
SUPERINTENDENT
THE PROJECT’S MANAGER
PROJECT SITE OFFICE TEAM - PROCUREMENT, ACCOUNTS, CLERICAL, STOREHOUSE, ETC_ NON-TECHNICAL
COMMISSIONING TEAM
INSTALLATION TEAM OF VARIOUS DISCIPLINES
Note: Based on the project and Project location, the link & authority between Project Manager and Site Manager is either Provided or Not provided. OR Project Manager and Site Manager both report to Senior Projects Manager at Head Office.
DRAWING OFFICE
Figure 2.1 Organisation structure – Head Office and SITE. Site Manager
Figure 2.2 Organisation structure – Site Office Personnel.
1 Secretary
1
1
Commissioning Manager
1
Drg. Office Mgr + Dbase Manager Proj. expeditor + Scheduler
1
Systems Engineers Application Engineers Materials Mgr + Safety officer
1
2.2 Site Operations Manual
Sometimes, the Project Manager or their designated Human Resources Head may retain some authority on Contract staff above a certain pay grade. The SITE Manager then fills in the “Employee Requisition” form and sends it to the Project Manager for processing the request in such cases. A typical Employee Requisition form is included below (Figure 2.3). c) Manpower Chart The SITE Manager should always have an up-to-date manpower list with him, with the names of all people working at the site. This list should separately indicate names of: a) Direct Contractor Company staff; b) Temporary / Contract / Casual staff; c) Subcontractor staff; d) Long- and short-term specialists, etc. A separate attendance register should be maintained to indicate who is currently working on site and is on site, or away on tour / inspection / leave, etc.
2.2.4 Engineering Administration Site operation mainly involves efficient administration of resources to meet the primary site objective of handing overall installed equipment to the Client. Meeting this broader objective involves a number of subsets. Adherence to National / International standards, Quality requirements, Safety aspects, etc. are some of them. These have to be achieved within the framework of meeting the contractual requirements, time targets and budgeted costs. Hence, sites have to plan and equip themselves adequately.
Figure 2.3 Employee Requisition Form.
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Some recommendations are listed below. 2.2.4.1 Engineering Standards On Site
Work done on site has to meet certain standards. Invariably, the site is involved in buying some cables, equipment, etc. Drafting work may also be carried out on site. It will be helpful to have copies of selected National / International / Owner standards at the site. An internal work list (IWR) is generated. 2.2.4.2 Documents to be Available On Site
A few documents are critical for the operation of the site. It will be the responsibility of the Site Manager to ensure that the latest revisions of these documents are available at the site office. A suggested list is given in this chapter, appropriate to Plant Construction such as Refineries, Power plant, etc. 2.2.4.3 Material Management
Material Management is essentially: ● ● ●
Material supply Material reconciliation at stages Spare parts management, including commissioning spares.
2.2.4.4 Tools and Tackles On Site
Site Engineers keep in touch with the Design Office and even the Integrated Control system (ICS), Basic Process Control system (BPCS), Safety Integrity Systems (SIS), etc. and Critical-Mission Contractors, where they are independent Subcontractors. They obtain clarifications and get assistance to resolve incidents and technical problems. In addition, they obtain most of the information by e-mail, e.g., database, graphic files, configuration files, version upgrades, etc. For this reason they need to be adequately supported, such as with PCs, etc. 2.2.4.5 Installation and Commissioning Schedule
The Contract with the Owner includes schedule dates for the commencement and completion of Installation of Equipment. Failure to meet these dates, generally, attracts penalties. The obligation from the Superintendent is to ensure that the Site / Equipment is ready for the Installation of Instruments and further commencement of project construction work, without any hindrances. Dates for these are also indicated in the schedule agreed with the Client. A precise role is to be defined by the Site Manager for the Superintendent. The Superintendent shall coordinate with other site disciplinary personnel for timely release of their equipment for Instrument works. The Site Manager will manage his resources to meet these dates. Hence, a copy of this schedule should be available on site and all Project team members should be fully familiar with the dates and details. In fact, all team leaders and heads of Subcontractors should have copies of this schedule. Failure by the Superintendent to get the site ready for Installation work will result in a delay. The Site Manager will be taking immediate action if such a delay occurs. 2.2.4.6 Detailed Schedules for Installation and Shutdown
Where a large number of activities are involved for completing an Installation or shutdown work, the Site Manager will get a detailed schedule prepared for such work. This detailed schedule should be supplemented with: 1) detailed list of all equipment needed for the work; and 2) detailed manpower list needed to carry out the tasks. This should include all staff – Direct, Contract and Subcontract staff. A copy of this schedule and planning should be sent to the Project Manager. Details of Progress made on the previous day, against this schedule, should reach the Project Manager by early next morning. Copies of this schedule and the progress made should be displayed at a prominent place on site. 2.2.4.7 Clearance Certificates
Work to be carried out on site will need permissions and clearance certificates. In a number of cases, people may have to attend an induction course before they are even allowed to enter the site. A notice (at times, even a week) for attending the induction course is to be given.
2.2 Site Operations Manual
All these need to be planned and obtained in advance. A separate chapter is provided on clearances and work permits in detail elsewhere. 2.2.4.8 Morning Meetings
The Site Manager or his nominee at Superintendent level will hold a meeting every day to discuss the progress and the bottlenecks. All Lead Engineers should attend this meeting. Among other things, the following should be discussed at the morning meetings: ● ● ● ● ● ● ● ● ● ●
Ensure that all equipment needed is available Ensure that all manpower needed are ready and available Clearance certificates / necessary work permits have been taken Drawings, manuals and documentation needed are on hand Safety Progress made the previous day Plans to make up for delays if any occurred Bottlenecks anticipated and solutions Precautions to be undertaken Help, of any, needed for clearance from authorities.
2.2.4.9 QA Procedures
A number of software changes are generally made during Testing and Commissioning on site. Unless these are properly controlled, they can get out of hand and lead to chaos. The above is one element of QA procedure. Likewise, the following measures are suggested: ●
●
● ●
●
● ●
● ●
All site incidents are to be covered by appropriate Site Incident Reports (SIRs). SIRs will be carefully preserved for future study and analysis. SIRs to be provided by a Unique numbering system All other changes requested by anyone should be covered by a Customer Work Request (CWR) form and duly approved by the Site Manager before action can be taken on them. CWRs to be provided by a Unique numbering system Design changes and database changes can be made only after obtaining approval from the Designers The Site Manager will decide whether the requested change constitutes a chargeable item. He will discuss, obtain and issue agreement with the Superintendent before authorising the change to be implemented Version Changes of S/W or H/W should be carried out after the receipt of CWR for the same. All CWRs should be carefully preserved These will apply to all cases including where the system has already been handed over to the Client A clearance certificate will be needed to carry out any type of work on the system, e.g., H/W changes, S/W configuration changes, Version updates, archiving, etc., to prevent any unauthorised changes being made to protect the system. Changes to Alarm and Trip settings require approval from the Commissioning Manager Appropriate Password protection is to be provided to prevent unauthorised changes Whenever configuration work takes place, the Site Engineers at the end of that day itself should save all configuration work on designated memory storages.
In addition to this, all configuration software should be saved to designated memory storage in the following manner. Two different memory storages have to be used for saving Configuration Data. One should be used on Mondays, Wednesdays and Fridays. The other should be used on Sundays, Tuesdays, Thursdays and Saturdays. Memory storages should be removable and be stored in separate locked steel cupboards. At the end of each fortnight, a complete backup (including graphics, code work, etc.) must be made on offline storage and should be stored at a safe location. When parameters (e.g., tuning constants, feed-forward constants, etc.) are changed, these should be uploaded before saving: ●
●
Changes made of any type should be recorded on the documentation – without any delay. All changes made should be clearly marked with a red pen. Documentation thus corrected should be kept in a location approved by the Site Manager as Documentation officer (usually fireproofed). This will be the Master documentation Once the changes on the system are made and the Master documentation created, all previous drawings should be kept in a separate place and be destroyed after completion of the project
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● ● ●
CAD drawings incorporating all changes made on the Master documentation should be on site within 10 working days with an appropriate revision number. On receipt of these CAD drawings, hand-marked Master documentation should be kept in a separate place and be destroyed after completion of the project At any time, the site should not have the same drawings with different version numbers Typically, Calibration and Loop checks are QA/QC procedures associated with I&C. There is more on this in Chapter 3 A final inspection summary logbook is submitted to the Owner for reference.
Typical Instrument Quality Control File (IQCF) headers are shown below for every activity as part of the Instrument Inspection Control File (IICF). For example, IICF 001 may be for “Field Instrument Installation Inspection” and its QCF tabulation may be as follows:
QCF no.
Date of Issue
Issued by
IQCF-001 July 31, 2021 TDH
Request for Inspection (RFI)No.
Area / Unit Subunit
Rev
Close date
RFI-310721-1
Crude/ 11-01
0
Aug 31, 2021
Note: Application for Inspection (AFI) instead of Request for Inspection (RFI) or Inspection Call Request (ICR) can also be used. This is issued for every inspection activity, however small. 2.2.4.10 Safety Policy
All personnel are to be committed to safety in the workplace at all times. To achieve this, the Site Manager will ensure appropriate management systems are implemented, as listed below: ● ● ● ●
●
Comply as a minimum standard, with all relevant statutory obligations Continuously improve occupational health and safety performance Provide adequate injury management resources to ensure timely and safe return to work Put in place a system responsible for ensuring safe work practices, and ensure that all Employees and Contractors are appropriately trained by Supervisors. They must monitor safety performance in their areas of responsibility and initiate action to improve any deficiencies found Every employee and Contractor is responsible for their own safety and the safety of others. All Employees and Contractors will report any incident that might impact on safety so that any problems can be rectified before an accident occurs. If it is safety-related, report it.
The commitment and full participation of all members, including Contractors, is required to reach the goal. The bottom line is “No business objective takes precedence over safety”. The implementation of the safety policy will be the responsibility of all staff and the staff of the Contractors. Line management has the responsibility of ensuring procedures and resources are in place to enable the policy objectives to be achieved, and to ensure that the policy is understood, implemented and maintained by all staff under their control. The Safety Manager or their presiding Officer has responsibility for the overall monitoring of compliance with the policy. 2.2.4.11 Installation, Testing and Commissioning
1) Site Installation A Subcontractor under the supervision of a Contractor Company Site Engineer generally carries out site Installation. Installation is carried out as per the Installation sketches / drawings. Installation may involve: 1) Field instruments / equipment; 2) Marshalling panels / I/O cubicles / Control panels; and 3) Laying of associated piping and cabling, etc. Field Instruments will be installed as per details given in Installation sketches. The Contractor may be involved in free issuing Instruments to the Subcontractor. Details of such issues should be recorded in a register titled “Free Issue to Subcontractors”.
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Installation of marshalling panels, I/O cubicles and control panels are carried out, generally by a Subcontractor under the supervision of a BPCS Engineer. Interconnections between the Field Instruments, marshalling panels and I/O cubicles are carried out as per wiring and cabling drawings. Often, some of these smaller drawings are prepared at site. It is to be noted that cable tag numbers and termination details go into the Master I/O Database for the project and the site staff will carry these out. Extreme care should be taken in allocating numbers to avoid duplication. Changes in the Master Database cannot be done without agreeing the change with the Design Office. 2) Additional Engineering Work and Estimation Often many Owners request additional I/O points on site. A couple of things have to be borne in mind while quoting for this additional engineering work: a) The Contract will specifically call for some spare I/O terminals to be made available for future use. Hence, the Contractor may not be able to use (during Installation and Commissioning) the few existing spare points on the I/O cards unless the Owner agrees to a reduced number for future use b) While adding an I/O, there is lot more work to be done associated with it, e.g., Master Database changes, calibration, testing, wiring drawing revisions, commissioning, graphics changes, alarm settings, control changes, etc. A spreadsheet that can be used for estimating the cost for such additional engineering, as shown in Figure 2.4. 3) Change Management The information available in the tender documents at the time of bidding may be partial or incomplete. Similarly, designs proposed and approved by the Owner during design development may not come up to their expectations. These lead to requests for a change of major / minor nature. The Owner shall make a provision in their budget for changes of this nature. It is the responsibility of the Contractor to note each and every change and claim to cover the costs. The steps involved in claiming for variations are: a) b) c) d) e) f)
To demonstrating that it is so To make a cost and time estimate for correcting it To indicate whether it will cause a delay in the project schedule To submit to the Owner by Contractor and get their written approval for the variation, cost and delays indicated To make / correct drawings / documents to reflect the variations called for and get the Owner to approve it To complete Implementation / Installation and Commissioning.
It must be noted that records are very important. Actions taken based on oral requests inevitably lead to confusion. Requests for any work, from the customer, to be done on site must be supported by a “Customer Work Request Form” (CWR) – whether they lead to a variation or not. A copy of this is provided in Chapter 6. The Lead Engineer will advise the Site Manager whether it constitutes a variation. Once the work has been categorised as a variation, then the Lead Engineer will use a “Scope Change Work Sheet” (SCW) for estimating the cost of variation. Also, specific to DCS and SIS/ESD systems, design-to-commissioning change management after systems received on site are usually too numerous; and hence require a separate change management sheet. It may be called a “Change Request for Systems” Sheet or CRS as given below. Usually, the System Manufacturer or System Integrator or Main Instrument Vendor may have a more detailed CRS form but initiation may be done by Client / Contractor on Site using the basic CRS form also. Also, it is not uncommon for the Client to increase the scope of supply and work for field items at some point through the progress of a plant installation due to various requests from their operations and engineering who are deputed to take over after commissioning. For the purposes of pricing, it is often treated by Contractors as a totally new scope / items not part of the existing contract and costing done specifically for changes and identified in a Scope Change Worksheet, shown in Figure 2.5. 4) Delays, Their Measurement and Notification Delays on site directly affect the project completion schedule, if no action is taken to accelerate the job; and acceleration costs money. If delays, which result in practical completion not being achieved on time, are outside the control of the Contractor, then the labour scheduled to finish the task will be lying idle until the clearance to proceed with the work is given, and this also costs money.
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2 Construction Management – SITE Operations Change Management Sheet DCS-ESD Control System Project Change Request Sheet Revision
Subject
CRS No: Date
Description
Change Originated from Customer Contractor Others Origin of modifications (Refer documents, correspondence, minutes of meeting....) Description of modifications Consequences
(Give details)
Technical (material, services, documentation................) Example of costing Item
Annunciator Engineering
Cost
Time Schedule
Total cost
Final Status of Change Request Agreed to be done Before FAT
After FAT
During FAT
On site
Cancelled
Issuer Checked Approved
Figure 2.4 CRS or Change Request for Systems.
It is up to the Contractor to provide a mechanism and documentary evidence for recognising the delay which will impact the schedule. Typical recognisable delays are: ● ● ● ● ● ●
Events beyond the control of the Contractor (industrial conditions, weather, etc.) Delays caused by the Owner and other disciplinaries like civil, mechanical agencies, etc. Increase in scope of work Variations and additional engineering Delays caused by authorities Breach of contract by the Client.
It is absolutely essential to thoroughly document the basis. Site diaries are to be maintained, even if the work is not progressing, recording the nature of the delay, its timing, the nature of work interrupted, amount of labour and material affected and the duration before the works can recommence again.
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Figure 2.5 Scope Change Worksheet.
The Site Manager serves a notice of delay and the estimated cost implications (which should include equipment hire, labour costs, price increases and overheads) on the Client. The “Delay Notification Form” is issued. 5) Extension Of Time (EOT) Delays which result in practical completion not being achieved and which are beyond the control of Contractor / Subcontractor will need to be recognised as to their impact on the schedule. The Site Manager usually applies for the date for practical completion to be extended. The Site Manager must provide supporting evidence behind this claim. After approval from the Owner, the Contractor shall be entitled to an EOT.
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It must be cautioned that not all delays entitle the Contractor to an EOT. Assessing the impact of delays on project completion time is a complex exercise. Meticulous keeping of records is essential. An “EOT variation calculation” spreadsheet is provided. 6) Managing Owner Data By Contractor The purpose of this procedure is to provide a traceable means of documenting and distributing supplementary information and variations from an initial contract. All projects are priced for tender purposes on an initial Owner requirement or specification. Any deviations from the original specification, which forms part of the Contract, must be assessed for project cost and delivery schedule implications. This instruction or procedure will assist in formalising assessment of the Owner information and variations. 7) Procedure – Recording Contract-Related Telephone Discussions a) Telephone conversations that pertain to the project shall be recorded on the “Record of Telephone Discussions” form b) A copy shall be made and a distribution list attached to the copy, at least to the immediate supervisor. The Project Manager will be on the distribution list c) The Master shall be filed in the master file under the appropriate section of the project d) Each generated record of telephone conversations shall be registered. 8) Procedure – Record of Conversation or Meeting Any conversations or meetings with the Owner that pertain to the project shall be recorded on “File Note” or “Minutes of Meeting”. Copies shall be made and distributed to all the attendees. The Master shall be filed in the master file under the appropriate section of the project. Each file note or MOM shall be registered and sequentially numbered. 9) Procedure – For Handling Documentation From the Owner Any documentation such as functional specifications, databases, instructions and the like, received from the Owner that pertain to the project, shall be registered with a project number taken consecutively from a document register. The front sheet and transmittal document of all Owner information shall be stamped with a date-received stamp. A copy shall be made and distributed. The Master, defined as the original with the date-received stamp, shall be filed in the master file under the appropriate section of the project. 10) Procedure – For Handling Drawings From the Owner a) Any drawings received from the Owner that pertain to the project shall be registered with the project number taken consecutively from the document register file “From Owner” b) All Owner information shall be stamped with a date-received stamp on each drawing c) A copy shall be made and distributed d) The Master shall be filed in the Drawing-Master file under the appropriate section of the project. A Contractor drawing number can be issued if deemed necessary.
2.2.5 Site Safety Practices and Rules 2.2.5.1 General Requirements
1) Major Legislative Requirements Where a method of work has been prescribed by the legislation, an employer shall carry out the work as prescribed. Fully documented details of the method of work (whether the prescribed or approved method of work) shall be prepared by the employer or a person nominated. This documentation shall be retained on the project site for reference and update. Where, due to special project circumstances, all or part of this Safety Management System is not applicable, the Contractor should determine safe alternative methods of work. These alternative methods of work should then be documented and the documentation retained on the project. Any alternative methods should not conflict with the requirements of the relevant legislation.
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Under the Workplace Health and Safety Regulations, the Principal Contractor and / or Employer: ●
●
●
shall keep a record in the prescribed form showing the particulars in respect of every work injury, work-related illness or dangerous occurrence that occurs at a workplace shall notify the particulars of that work injury, work-related illness or dangerous occurrence not later than 24 hours for a preliminary report and a full report not later than three clear days after its occurrence shall make that record available for inspection when requested to do so by Concerned authorities.
In addition, the regulations require that where any serious personal injury, work-related illness or dangerous occurrence occurs on or in relation to a place of work, notice shall be given to the Division of Workplace Health and Safety in the prescribed form. This notice shall be given immediately after the occurrence of a serious personal injury or dangerous occurrence, or of becoming aware of a work-related illness (but not later than 24 hours). The Contractor and each of his Subcontractors are required to demonstrate that they are complying with the documented procedures contained in this Handbook. Evidence of compliance shall be through quarterly audits that are completed by a Contracting Company nominated officer. Non-conformances identified through these audits must be addressed promptly and diligently. Suitability of corrective action shall be determined at the subsequent audit. Where there are any concerns with the use of this Handbook as provided, they should be directed to the Director of Contracting Company. These concerns should be formally recorded on a Document Change Request form or a corrective action request form. These documents shall then be processed in accordance with the relevant Owner Company procedures. Wherever these procedures have reference to Country Standards and Legislation, it is the responsibility of the Contractor to provide that documentation where appropriate and ensure that it is kept current and up to date. These documents may be held by the Owner Company but must be kept current and up to date by the Contractor. 2) Definitions To assist in using this Safety Management System, some definitions are given below. Generally, these are the same as those in the Workplace Health and Safety Legislation: ● ●
● ●
●
●
●
●
●
“Approved” means approved by the Regulator “Competent person” means a person who by reason of qualifications and experience has the skills necessary to perform the duties under the regulations in respect to which the expression is used and who has been appointed by the employer to perform those duties “Employee” means an individual who works under a Contract of Employment or apprenticeship “Employer” of either an Owner or a Contractor means a corporation which, or an individual who, employs persons under contracts of employment or apprenticeship “Inspector” means any person who holds an appointment as such within the Country’s Division of Workplace Health and Safety “Mobile Plant” means any earthmoving, road making or other mobile machines, like a crane, etc. This term does not include items of plant which are mobile for transport between projects, but operate in a fixed mode on the project “Non-employee” means a person reasonably at a workplace on the project who is not an employee of the Owner Company or any other Contractor or person in control of the workplace. Examples are: Local Government authorities, delivery truck drivers, members of the general public, etc. “Person in Control of a Workplace” means either the Principal Contractor or a Subcontractor and can include a representative of the Contractor Company or the Principal Contractor or Subcontractor in control of a workplace used by employees and non-employees “Personal Protective Equipment” means clothing or equipment which, when worn or used correctly, protects part or all of the body from identified risks of injury or disease in the workplace. The term includes multiple items and may include: – eye protection – protective footwear
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– protective headwear – gloves – hearing protection – high visibility safety garments – respiratory protective equipment – safety harness, full body harness, etc. Note: Personal protective equipment will be referred to in this Safety Plan as PPE. ●
● ●
“Site” shall be taken to mean all areas encompassed by the project, including the workplace and all associated offices, amenities and facilities “Subcontractor” means any Subcontractor engaged by the Contractor “Incident” is an unplanned event that causes or could have caused injury or damage to personnel or property and involves: i) an employee of a Consultant, Contractor or Subcontractor working on behalf of the Contractor Company, and ii) occurs at a place under the control of the Contractor Company or its Principal Contractor, or a Subcontractor while engaged in activities related to the work, or iii) involves operation of the Contractor Company’s or the Principal Contractor’s property, plant or equipment.
“Major Incident” is an incident that: ● ● ● ● ● ●
causes death or disabling injury to a person results in Lost Time Injury (LTI): Alternative Duties / Medical Treatment is likely to give rise to public comment is likely to result in legal proceedings against the Owner Company or the Principal Contractor causes significant property damage is a near hit has the potential to cause any of the above is a near hit.
“Minor Incident” is an incident that results in: ● ● ●
First Aid injuries minor property damage a near hit with limited consequences.
“WHS and R” means Workplace, Health, Safety and Rehabilitation 3) Site Safety Management Meetings: Workplace health and safety matters are to be Item 1 on the agenda of all site meetings between the Owner Company, the Principal Contractor or Subcontractors, or other workplace personnel, as the case may be. The Principal Contractor and / or Subcontractor’s Site Manager shall convene Site Safety meetings on a monthly basis. The agenda items shall include: ● ● ● ●
Safety performance statistics Safety issues and resolutions Progress reports on the safety training programme Disciplinary measures required for breaches of SITE safety by staff, employees and / or Subcontractors.
Workplace Safety Committees are required to hold regular meetings to discuss issues related to the health and safety of the workforce; and provide recommendations to Management. Whenever necessary, the Principal Contractor will convene safety co-ordination meetings with the Subcontractors to discuss safety issues affecting the works in progress. 4) Toolbox Safety Meetings Toolbox Checks are a means to check that the Toolbox is as-issued and returned in place, leaving no tool in the workplace to cause accidents. However, Tool Box Safety meetings are to be convened daily (or some weekly based on trade) and should be used to encourage two-way communication and participation in the continuous improvement process.
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Topics for discussion may include: ● ● ● ● ● ●
Safety performance to date Discussion of progress of work on the work site and any related safety issues Any changes to the safety manual or procedures Safety awareness topics or specialised topics of particular relevance to the work group Specific items such as Job Safety Analyses (JSAs) Any specific issues that the Owner Company require to be discussed.
Assistance with the preparation for Toolbox Safety Meetings is available through Safety Personnel. It may also be appropriate in certain circumstances for Safety Personnel to assist with the delivery of the topic. All project personnel of the rank of Supervisors and their workforce will be required to attend the Toolbox Meetings. A record of attendance at Toolbox Safety Meetings will be recorded and details retained. The Minutes of the meeting will be recorded. These will be displayed on the notice boards in the crib rooms. 5) Workplace Safety Committee The Workplace Health and Safety Committee will comprise the Principal Contractor’s Site Manager or nominee, their Site Safety Co-Ordinator and an employee representative at a minimum. The meeting is to be held at monthly intervals with the Minutes documented and displayed on the notice boards. A copy shall be forwarded to the Owner Company. 6) Workplace Safety Audits and Inspections The Principal Contractor, Owner Company and other regulatory bodies, such as Department of Transport, will carry out Workplace Health & Safety (WHS) audits. The Principal Contractor shall carry out WHS audits within three months of the commencement of the project and every two months thereafter for the life of the project. The Principal Contractor shall carry out weekly site safety inspections conducted by the management and employee representative. Copies of the audits and inspections will be recorded and retained for a minimum of 12 months or until Project completion, whichever is later. Supervisors are required to inspect their areas and have hazards and deficiencies removed and rectified on an ongoing and minimum daily basis Personnel are required to report any unsafe areas or work practices to their supervisors The progress of all WHS audits and site safety inspections will be reported in the monthly progress reports to the Project Manager and Owner Company. The Project Manager and Owner Company will verify the effectiveness of these Safety Audits and Inspections through the Quarterly Company Safety Audit. 7) Site Safety Co-Ordinator The Site Safety Co-Ordinator will carry out regular safety audits of the workplace and discuss the results with the Site Manager. These shall be carried within three months of the commencement of the project and every two months thereafter for the life of the project. 8) SITE Manager Review The Site Manager will monitor site conditions and ensure that all activities comply with the agreed work methods statements. These statements can be modified to suit the activities being carried out in the workplace as work progresses. These shall be carried within three months of the commencement of the project and every two months thereafter for the life of the project. 9) Procedure for Unsafe Work Situations Personnel in the workplace are to be made aware of the procedures for reporting unsafe conditions or unsafe work practices during their initial Safety Induction. Should any person become aware of an unsafe situation in the workplace, that person shall be expected to notify the person in charge of the area immediately.
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The following procedures shall be implemented: a) Hazardous Conditions: ● The hazardous condition shall be rectified immediately ● If unable to do so, the hazard shall be isolated and signposted to warn other personnel of the danger ● As soon as practicable, the hazardous condition shall be rectified. b) Hazardous Work Procedures: ● If the issue involves an immediate threat to health and safety, work shall cease in that area until the issue is resolved ● The work procedure is to be reviewed by the Workplace Safety Committee and the issue resolved by joint consultation ● If the issue cannot be resolved by consultation, Management shall seek assistance from the Workplace Health and Safety Authority ● Supervisors are responsible for notifying the Site Manager of hazardous conditions or unsafe work procedures in their area of responsibility ● They are to rectify the hazardous condition if competent to do so. The Site Safety Co-ordinator is to inspect the hazardous condition in the Owner Company with a member of the Workplace Safety Committee to ensure that effective action has been taken to rectify the matter. The Site Manager shall not, under any circumstances, allow personnel to work in areas that have been identified as unsafe. 10) Risk Assessment and Hazard Control Measures It is the duty of every employer to ensure that risks to the health and safety of all persons in the workplace are identified and that appropriate control measures are implemented to eliminate or minimise such risks. Risks to health and safety are to be controlled by elimination of the hazard or if this is not practicable, substitution by a less hazardous method of operation. If it is not practicable to eliminate the hazard or substitute with a less hazardous method of operation, one or more of the following measures are to be applied as appropriate to control the risk to health and safety: ● ● ●
●
isolation of the hazard engineering controls adoption of safe work practices, including changes to work methods which minimise the risk of injury and illness from the hazard the provision, maintenance and proper use of suitable approved PPE.
Work method statements are to be developed, in consultation with the Workplace Safety Committee, by the person in charge of the particular work area or process. Work method statements are to rely on accompanying Safety Audits for implementation. Work method statements are not to be amended without consultation with the Workplace Safety Committee. The work method statement and any alterations or amendments must be made known to all persons in the workplace who may be affected by the works in progress. Tool Box Meetings can be used to develop applicable Safety Audits. 11) Material Safety Data Sheets Material Safety Data (audit) Sheets (MSDS) are to be maintained on site by the Principal Contractor and Subcontractors for any hazardous chemical, substance or material prior to being brought onto site. A copy of the MSDS will be retained in a central register at the Principal Contractor’s site office and be readily available on request by any employee. 2.2.5.2 Administration
a) Employee Records Employers will be expected to maintain a current employee file, at an immediately accessible site location, identifying each employee’s next-of-kin (with contact telephone number and address) and any known medical problems, including allergies, regular medication, etc., for use in the event of injury or illness at work Prior to commencing work on the project, employees, including those of Subcontractors, shall have attended a preemployment medical examination designed to check the person’s suitability for the proposed work to be carried out.
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b) Photography Unless specific approval has been granted by the Owner Company or the Principal Contractor, the taking of stills, movies or video pictures of site activities or Installations is prohibited. The Owner Company will not unreasonably withhold approvals for such activities where it is required for external compliance audits, accident or incident investigations. c) Visitors Visitors to operational workplaces are required to register their name and reason for the visit with the Principal Contractor and We can leave as such also must be accompanied at all times whilst at the workplace. d) Site Safety Requirements The Owner Company or the Principal Contractor may, from time to time, promulgate site safety requirements relevant to the work in progress. The Site Safety requirements will be binding on all persons in the workplace from date of issue. e) Mobile Telephones The use of mobile telephones on site may be restricted from time to time, depending on the activities being conducted at the time. f) Safety Promotion The Owner Company, the Principal Contractor and any Subcontractors should actively promote safety awareness throughout the project in order to maximise safety attitudes learned during the Safety Induction. Managers and Supervisors shall demonstrate their commitment to safety on the Project by leading by example and shall instruct and encourage employees to work safely at all times. A programme of safety awareness posters shall be put in place to complement the programme of Supervisor Safety Talks. g) Safety Targets Companies have a single primary target for safety on this project – NO LOST TIME ON INJURIES. The personnel injury target is of utmost importance to the Owner Company. The safety target attempts to emphasise: ● ● ●
the great value placed on the health and safety of all personnel in the workplace a commitment to safety at all levels within the organisation accidents are not inevitable, but that they can be prevented with a mixture of training, attitude and care. The Owner Company’s secondary target is to prevent through the safety management process any damage to property:
h) Discipline Adherence to discipline at Site shall have been briefed to Employee prior to start of employment. i) Working Under the Influence. The Owner Company’s policy in relation to Drugs and Alcohol is zero tolerance. That is, no quantity of drugs or alcohol whatsoever will be tolerated on the site. The possession of any drugs or alcohol, or detection of any person being affected by drugs or alcohol, will require immediate action as outlined below. Employers have an obligation to ensure the health and safety of employees and any other persons at the workplace. This includes the health and safety of any alcohol- or drug-affected person. The following rules shall be implemented: ● ● ●
The possession, use or consumption of drugs of abuse and / or alcohol at the workplace is prohibited Persons in possession or affected by them are not allowed in the workplace. Managers and Supervisors shall ensure that personnel in the workplace who appear to be affected by drugs or alcohol are immediately removed from risk of danger to themselves.
The person shall be counselled in the presence of their Workplace Health and Safety Representative to ascertain if they are on medication prescribed for illness or injury by a medical practitioner. If the counselling session reveals that prescribed medication is not the cause of the person’s behaviour, they will be advised that the Owner or Contracting Company will not allow any person apparently under the influence of drugs or alcohol to place themselves or others at risk in the workplace. The person is then to be advised that they have breached their Contract of Employment and will therefore have his services terminated on the grounds of wilful misconduct.
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Any person who places the health and safety of any other person at the workplace at risk, i.e., by being affected by alcohol or drugs while at the workplace, commits an offence under the Workplace Health and Safety Act.
Other Act rules are listed below. 1) Working in an Unsafe Manner Where employees of the Owner Company or the Principal Contractor disregard safety practices and procedures, or fail to wear the clothing and personal protective equipment supplied, the following procedure, designed to encourage improvement in safe working practices, shall take place. When a member of a Subcontractor’s workforce is found to be in breach of the Site Safety requirements, the employer will be directed by the Owner Company or the Principal Contractor to remove that person from the project. The above rules apply equally to management personnel of the Owner Company, the Principal Contractor and Subcontractors. 2) Incident Reporting The Owner Company and the Principal Contractor’s Site Manager shall be notified immediately of the occurrence of an incident at the site. If the incident involves the Owner Company’s or the Principal Contractor’s personnel or property, the Site Manager shall conduct an investigation as to the causes of the Incident and record the information. The Incident Investigation Report shall be forwarded to the Owner Company within 24 hours of the occurrence of the incident and shall include recommendations to avoid a recurrence of the incident. The Owner Company and the Principal Contractor shall take the necessary steps to amend procedures or remove any hazards identified during the investigation. Any incident involving a Subcontractor shall be investigated by the Owner Company or the Principal Contractor. Subcontractors shall submit a monthly health and safety report to the Principal Contractor for inclusion in the Principal Contractor’s report to Owner Company. The report shall provide the following information for the month: ●
● ● ● ● ● ●
a summary of all major and minor incidents during the month including “near hit” incidents, medical treatments, first aid treatments, alternate duties and lost time incidents cumulative totals for the above for the preceding month and the cumulative totals since commencement of the work monthly and cumulative totals of exposure hours number of days lost due to Lost to Incident (LTI) number of days worked since last LTI and medical treatment status of follow-up action arising from incident investigations summary of safety highlights including initiative taken to improve safety performance and planned activities for the following month.
The accident and reporting process shall involve a review of all accidents and incidents by the Project Manager with the Owner Company. The PM or Owner Company will: ● ● ●
● ● ● ●
ensure that a central system is in place to record the incidents review all reports and track recommendations ensure that all incident data and investigation findings are incorporated into the Exposure Record Inventory of the Owner Company Risk Control and Management Plan ensure that all relevant information is quickly and effectively communicated to all relevant external agencies review all relevant emergency and control procedures ensure that any investigations are undertaken by suitably qualified and skilled personnel ensure that any preventative measures are applied within the safety management system.
In certain instances, rehabilitation activities may be referred to an approved Rehabilitation Provider by the treating physician, the employee or some other interested party. Under those circumstances, the Site Manager shall offer full co-operation to all involved. Subcontractors shall ensure that the procedures listed above are followed within their own organisation for personnel registered as employees on this project.
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3) Safety Training and Certification record General Training records and qualifications will be retained by the employing body or Contractor in the employee’s personnel employment record. 4) Safety Inductions Under the Workplace Health and Safety Act, the employer shall ensure that employees have received instruction in workplace health and safety issues. All personnel required to work on the project are required to attend a Safety Induction Course. Instruction will be supported by appropriate written safety material to be distributed to all persons being trained. Safety Induction will include instructions on: ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●
Obligations Drugs and alcohol in the workplace Emergency procedures Hazardous substances Personal protective equipment Barriers and warning signs Vehicle rules Oxy-acetylene work, welding, cutting and heating Cranes and lifting Handrails Ladders Working platforms Manual handling Specific site requirements Reporting and controlling hazards Reporting injuries / accidents and near misses Toolbox safety meetings Hazardous substances or gases (e.g., H2S) Environmental issues and significant sites Restricted areas Aboriginal culture Explosive power tools Electrical equipment Compressed air Confined spaces Housekeeping.
a) Specific Safety Training When an employee is required to perform a particular task that has hazards associated with it, and those hazards have not been covered in previous Safety Induction Courses, the person’s Supervisor shall ensure that the employee is given specific safety information, training and instruction to protect him or her from those hazards. Supervisors shall ensure that employees clearly understand the nature of any hazard likely to be experienced and the controls put into place to eliminate or minimise those hazards, before they are permitted to commence work each day. Where PPE is provided, appropriate training and instruction shall be given to ensure employees understand how to use the personal protective equipment correctly. With some items of personal protective equipment, e.g., safety harnesses, improper use can cause injury or death. Some items also need to be fitted to the wearer to ensure that the necessary level of protection is provided, e.g., eye protection, protective footwear, etc. Supervisors, including those of Subcontractors, shall conduct “Toolbox” safety talks at regular intervals after consultation with the Workplace Safety Committee on the subject matter to be discussed. Details shall be recorded.
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Office employees shall attend safety training sessions at an appropriate On-Site Training Facility on a monthly basis. Employees of the Principal Contractor and its Subcontractors shall attend quarterly training sessions as promulgated by the Principal Contractor’s Site Manager. b) Certificates in a Prescribed Occupation Under the Workplace Health and Safety Regulations, the following occupations require the operator or user to hold a valid National Certificate to Work in a Prescribed Occupation or a Training Log Book, applicable to the item being operated or used: ● ● ● ● ● ● ●
Crane Driver Dogger Explosive-powered tool operator Boilermaker / welder Hoist driver Rigger Scaffolder.
It is the employer’s responsibility to ensure that: ● ●
work is only performed, and a person is only employed to perform work in a prescribed occupation on this project if the person performing the work is a holder of a current Certificate to Work in a Prescribed Occupation; or is listed in a Training Log Book and is supervised
c) Production of Certificates Any holder of a Certificate to Work in a Prescribed Occupation, or permit, may be required to produce that document to an inspector or employer on request. Personnel carrying out any work requiring a Certificate to Work in a Prescribed Occupation are to have in their possession a valid certificate d) Operator Instruction Before an operator of plant or equipment performs any allocated task, the Supervisor shall ensure the person has been adequately instructed in: ● ●
procedures used in safely performing that task hazards that may occur during performance of that task.
Any person found to be wilfully operating plant or equipment in an unsafe manner will be immediately removed from the project on the grounds of wilful misconduct e) Skills Competency Tests Potential employees may, at the discretion of the employer, be required to undertake competency tests in relation to the skill requirements of the particular level of the classification structure to which they are appointed Employees shall be advised of this requirement at the time of their initial interview for employment on the project If required, the skills tests will be carried out under the supervision of the employee’s Area Supervisor who will record the results Employees who fail to reach the competency standards set for the various skill levels shall not be employed in that particular work process until such time as the appropriate skill levels are attained. (e.g., all support fabrication related welding and instrument fittings socket / other welding have to be carried out by approved / qualified welders only). A typical Trade skill TEST form is shown in Figure 2.6. The skill test forms for all trade associated with I&C for use are under Chapter 6. f) Other workplace hazards 1) Housekeeping A high proportion of workplace accidents are directly related to unsatisfactory housekeeping standards. Companies therefore expect their employees, and Contractor and Subcontractor personnel, to co-operate towards adoption of a “clean up as you go” policy
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Figure 2.6 Trade Skill Test – Typical form.
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Storage and stacking of materials shall be restricted to areas approved by the Principal Contractor. Such storage shall be safely arranged, and if storage hazards (e.g., toxicity, flammability, etc.) exist, appropriate barriers and signs shall be provided Solid waste materials shall be disposed of into the bins provided on site by the Principal Contractor or its Subcontractors, as the case may be Liquid wastes shall only be removed by a licensed Waste Disposal Contractor Under no circumstances shall liquid wastes, including contaminated water, be disposed of through site drains or into any adjacent waterway Details of the management of all types of waste and construction debris shall be made available in the Environmental Management Plan developed specifically for the project. 2) Loading and unloading trucks i) The following rules shall apply when loading / unloading solid materials: ● Never enter or leave the cab during loading / unloading operations ● Watch for and avoid other vehicles, personnel and structures on entering or leaving the loading area ● Stay a safe distance from trucks ahead at the loading point, and follow the directions of the crane chaser or dogman before moving into the loading position. Only move off when signalled that loading is complete ● Load material, e.g., timber, so that it does not project beyond the truck body and present a hazard to other plant, people or structures ● Where material is to be transported on a public road, Traffic Regulations require that material projecting either 1.2 m or more beyond the front or rear of the vehicle, or 150 mm on either side, shall have a visible red flag or object fastened to the projecting end. Unusually wide or long loads require a permit from Government authorities ● Secure loads at the lowest possible level on the tray with ropes or chains, and take special care when the truck is to travel over rough terrain. Cover up with tarpaulins or nets as appropriate. ii) The following rules shall apply when unloading loose materials: ● Lower truck bodies before leaving the dump area ● Only raise truck bodies to unload materials on surfaces where the vehicle will remain stable and upright ● Never raise truck bodies to within a specified distance of overhead power lines unless approval has already been obtained from a local electrical authority ● Take special care when tipping a load or spreading screenings on a road. With the tray up, trucks are less stable and are more likely to roll over, particularly on hilly sections or roads with surface irregularities or steep shoulders. Check that the raised tray will not foul overhead power lines or telephone wires. 3) Manual Handling Manual handling means any activity requiring the use of force exerted by a person to lift, lower, push, pull, carry or otherwise move, hold or restrain any animate or inanimate object. These activities may stress or strain the body when the force required exceeds the inspiratory capacity of a person to safely provide, or the activity is improperly undertaken. The risks from manual handling shall be assessed and reduced at the workplace, in accordance with the requirements of the “Advisory Standard for Manual Handling”. Construction sites by their nature are constantly changing. As the project takes shape the physical characteristics and nature of risks change dramatically. This creates a great deal of difficulty when it comes to redesigning work systems and work tasks. Nevertheless, a number of general principles apply. If employees are educated about how to reduce exposure to risk, and the employer is committed to risk reduction, effective changes can be made. The Advisory Standard for Manual Handling called up under the Workplace Health and Safety Act, has information to assist employers in meeting their duty of care in this respect. Generally, the following principles apply: ● ● ●
● ● ● ● ●
use smooth, controlled actions and movements avoid repetitive bending, twisting and overreaching movements design the workplace and work station layout to allow employees to use an upright and forward-facing posture, to have good visibility of the task and to perform the majority of tasks at about waist height and within easy reach decrease the frequency, repetition and duration of the manual handling activity where practicable store frequently used items between knuckle and shoulder height when carrying a load, keep it as close as possible to the body for seated work, avoid lifting, lowering or carrying loads above 4.5 kg avoid lifting, lowering or carrying loads above 20 kg, where practicable
2.2 Site Operations Manual ● ● ●
●
never lift, lower or carry loads above 55 kg without mechanical or other assistance persons under the age of 18 should never lift, lower or carry loads in excess of 20 kg without mechanical or other assistance extra care should be taken when lifting, lowering or carrying awkward, large, unbalanced, slippery, soft, hot, cold or sharp-edged loads poor housekeeping, inadequate lighting, lack of space, poor walking surfaces, uncomfortable working temperatures, lack of training in manual handling techniques, young or old age, all increase manual handling risks.
Manual handling risks can be controlled by: ● ● ● ● ● ● ●
job redesign changing the weight, size or shape of the load changing or rearranging the workplace layout rearranging the materials flow using different actions, movements and forces to do the task modifying the task through mechanical assistance or team lifting mechanical handling assistance, providing mechanical handling equipment and appropriate training to use the equipment
Training ●
where the previous control options do not reduce the manual handling risk then appropriate instruction, training and / or education shall be provided.
4) Noise Appropriate measures shall be implemented to ensure that risks to health and safety due to excessive noise are controlled. A hazardous noise survey shall be carried out on all plant and work activities to identify potential risks to health and safety from excessive noise and to ensure compliance with “Hearing Conservation”. The hazardous noise survey shall include: ● ● ●
the identification of plant and work methods likely to create a hazard from excessive noise an evaluation of the likely effects of any noise hazards identified on the health and safety of persons at that place of work the need for measures to control any hazards identified at that place of work.
Risks to health and safety identified during the survey are to be controlled by elimination of the hazard or if this is not possible, by application of one or more of the following measures: ● ● ● ●
isolation of the hazard engineering controls adoption of safe work practices, including changes to work methods which minimise the risk of injury from the hazard the provision, maintenance and proper use of suitable approved PPE.
Noise control strategies for employees shall be completed in accordance with the advisory standard for noise. 5) Heat Exhaustion In addition to the UV exposure, all Contractors to be observant for and protect persons from excessive heat exposure. Cool water shall be readily available at the site with all persons encouraged to drink frequent small amounts. Crib areas will provide cool areas out of the Sun. All persons are to be alerted to the dehydrating effects of alcohol; drinking alcohol the night before work will make a person more susceptible to the effects of heat exhaustion. Any person who shows symptoms of heat exhaustion ranging from vagueness, sluggishness, nausea and headaches to having abdominal / muscle cramps must be sent for immediate first aid attention. If left uncorrected, a severe medical emergency can result. 6) Operation of Plant Employees shall be given relevant information, training and instruction on the health and safety procedures associated with the operation of plant at the workplace. Employees must be trained in the identification of the risks to health and safety associated with the operation of plant. All physical guards on plant shall be of solid construction and securely mounted in such a manner that they cannot be altered or detached without the aid of a tool.
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7) Protruding Objects The ends of all protruding objects capable of causing injury to persons at the workplace shall be covered. 8) Slips, Trips and Falls Slips, trips and falls are a very simple way in which serious injuries occur in a workplace. Almost all of the vertebral fractures which occur on construction sites are the result of falls. Modifying the work environment is the most effective way of reducing the risk of falls. The risk of slips, trips and falls shall be reduced by: ● ● ● ● ●
● ● ● ● ●
keeping all pedestrian areas free of tripping hazards where practicable, ensuring all pedestrian surfaces are non-slip or that appropriate footwear is worn ensuring the edges of walkways, stairs, etc. are clearly visible to pedestrians providing hand rails on walkways, stairs, etc. These are particularly needed when accessing machinery complying with all trenching regulations, e.g., providing barricades around excavations where a person may fall a distance of 1.8 m or more complying with all scaffolding regulations providing adequate hand and foot holds for access to vehicles or machinery ensuring that all ladders are well-maintained and used correctly, particularly with respect to surface anchoring ensuring clear paths and good visibility where tandem carrying of goods, materials, etc. is necessary using safety harnesses and safety lines where a person may fall 1.8 m or more and it is not practicable to provide guardrails, midrails or edge protection.
9) Smoking in the Workplace To ensure compliance with the Workplace Health and Safety Act to “provide a place of work that is safe and without risk to health”, the smoking of tobacco products is not permitted in any site office, training room, crib shed or any other area where personnel could be exposed to the risk of passive smoking. Passive smoking describes the inhalation by non-smokers of other people’s tobacco smoke in the form of either “mainstream smoke” inhaled and exhaled by the smoker or “side stream smoke” emitted directly from the burning tobacco. Smoke inhalation in this manner is therefore unintended or involuntary, placing passive smokers at risk of getting diseases caused by tobacco smoke without lighting up themselves. Where signs prohibit smoking, these shall be obeyed without question. Failure to comply with smoking restrictions may result in removal of the offender from the workplace. All personnel are to be advised of the smoking restrictions during their initial induction prior to commencing work. 10) Use of Electric Power All electrical wiring installations and equipment used in the workplace must be safe for use. The use of electric power shall comply with the Workplace Health and Safety Regulations and CE certified as a minimum. Where a more specific provision is not made in the Workplace or Mining Health and Safety Regulations, they shall conform to the provisions of “Wiring Rules”, and the local Supply Authority Service and Installation Rules. Electrical equipment that does not comply with the provisions of the Workplace Health and Safety Regulations will be removed from the workplace. 11) Welding, Cutting and Grinding Operations The process of welding or cutting shall be performed in accordance with local standards: a) b) c) d)
“Protective Clothing for Welders” “Fire Precautions in Cutting, Heating and Welding Operations” “SM Welder Certification Code”, and “Electrical Welding Safety”.
All welding activities shall be conducted in such a manner that personnel in and around the area are not subjected to arc flash. Portable screens shall be used where appropriate. Prior to undertaking any hot work, consideration shall be given to the effect of sparks and slag upon personnel and property. Signs and barricades shall be installed beneath welding / cutting operations and combustible materials shall be removed or covered to reduce the risk of fire.
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Welding fumes are to be removed from the work area by providing adequate ventilation and / or mechanical fume extraction equipment. Appropriate protective clothing and hard hat with protective welding shield should be provided and worn by all personnel involved in welding or cutting operations. Where any grinding or cutting is being undertaken, the operator and any other personnel assisting in/or near proximity to the activity shall wear goggles or a face shield with sufficient coverage to protect the eyes and face from high-speed projectiles from the grinding or cutting activity. Where appropriate, particular care shall be taken to ensure sparks are contained and do not cause clothing or materials to ignite or produce a hazard to other persons nearby. In general, Welder Qualifications must be verified for the person’s WPS/WQS procedure knowledge. 12) Working at Heights “At height” is defined as above 1.8 m. Wherever possible, employees will work within protective barriers. Where this is not possible and there is a risk of falling, the following shall take place: ● ●
●
Identify the hazards involved including access or egress to a work area and the risk involved Control the risk by using one or more procedures or pieces of equipment including safety harness, fall arrest systems and anchorages to eliminate the risk of a person falling If required, proper scaffolding / staging has to be erected and kept during duration of the works and during inspection.
13) Working in Confined Spaces All conditions, precautions, etc., as outlined in mandatory country standards (i.e., AS-2865 “Safe Working in a Confined Space”), shall be complied with when working in confined spaces (as defined). Where a person is required to enter a confined space while at work, another person shall be appointed to assist that person in the event of an emergency. All reasonable steps must be taken to ensure the health and safety of the person working inside the confined space and the person appointed to assist, including: ● ● ● ●
the testing of the atmosphere in the confined space the ventilation, cleaning or purging of the confined space the provision of an appropriate respiratory device the appointment of a person or persons outside the confined space to ensure that adequate communication, support, first aid and rescue services are available to the persons within the confined space.
A person who enters a confined space must have received, within the preceding six months, adequate training and instruction in: ● ● ● ●
the use of respiratory protective devices the use of suitable rescue and first aid equipment the use of any other equipment provided for the work in the confined space safe procedures for working within a confined space.
If, for any reason, the conditions specified in standards (i.e., AS-2865) cannot be complied with, an exemption from the Regulation should be sought in writing from the division of workplace health and safety before work commences. Any request for an exemption from the regulations must be discussed with and agreed to by the Principal Contractor and their Workplace Safety Committee. Where it is impracticable to erect handrails or provide safety harnesses to prevent persons falling into water, approved life jackets or buoyancy vests shall be worn by all persons exposed to the risk. 14) Working With or Near Compressed Gas Equipment a) A person who uses compressed gas in the performance of any work must be aware of the hazards associated with the use of the compressed gas and be reasonably competent in its use b) Reasonable steps shall be taken to control, at their source, hazards associated with the use of the compressed gas and to ensure that safe systems of work are maintained c) Appropriate equipment shall be provided to control the supply of gas effectively and to ensure that the gas pressure is appropriate for its particular use
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d) Any equipment used in connection with the supply of the compressed gas (including hoses, connections, gauges and pneumatic tools or machinery) shall be maintained in effective working order e) Hoses which are not permanently attached to equipment shall be stored safely and the gas supply isolated at the source when it is not being used f) A person shall not use compressed gas for an inappropriate purpose that could endanger his or her own health or safety, or the health or safety of another person g) A person shall not use compressed gas to clean dust from clothing h) If there is a risk of injury to the person’s eyes through the use of the compressed gas, the person shall be provided with and use suitable eye protection i) When a compressed gas cylinder is not in use, the cylinder shall be safely stored and protected from exposure to excessive heat j) When a compressed gas cylinder is being moved or used, suitable precautions shall be taken to prevent damage to the cylinder, or to any associated fitting k) Compressed gas cylinders shall be secured in an upright position when in use and when in store l) A “Dangerous Goods Keeping Licence” shall be obtained for the storage of more than seven of any of the following: ● ●
Flammable (LPG and Acetylene) gas cylinders Oxy-Cutting (Oxy-Acetylene) carts.
Containers or sheds used to store gas cylinders shall be sufficiently ventilated to prevent a hazardous build-up of leaked gas. 15) Working With or Near Hazardous Substances Under the Workplace Health and Safety Regulations, manufacturers and suppliers shall provide Material Safety Data Sheets (MSDS) for all hazardous substances supplied. Employees who receive an MSDS must treat the substance as a hazardous substance in accordance with requirements of the Workplace and Mining Regulations. When a hazardous substance is first introduced into the workplace, all employees shall be advised of the safety requirements for that hazardous substance. Where a significant proportion of employees are non-English speaking, the MSDS shall be translated into the appropriate language. Arrangements shall be made for protecting safety and health in connection with the use, handling, storage or transport of such hazardous substances. Every person employed in the use or handling of a hazardous substances shall be informed of: ● ● ●
the effects and symptoms of exposure to such substance the ways in which exposure may be avoided, including the proper use of engineering controls the selection, use, care and maintenance of any PPE provided for the protection of persons against the effects of that hazardous substance.
A register of hazardous substances used in the workplace shall be kept readily available for inspection by health and safety representatives. 16) Work Involving the Use of Ladders ●
●
● ● ● ● ●
Suitable ladders shall be provided for the safe means of access of persons to all places where they may have to work until such time as temporary or permanent stairways or other methods have been completed and are available as safe means of access Every ladder shall be securely fixed so that it cannot move either from its top or bottom points of rest. If such fixing is impractical, a person shall be positioned at the bottom of the ladder to prevent slipping Effective means shall be provided to protect a ladder from collision No ladder, except a trestle ladder, shall be used to support a plank upon which a person has to work Ladders shall extend at least 1 m above any landing Defective ladders are not to be used under any circumstances and must be removed from site Metal ladders, ladders reinforced with wire, or any other electrically conducting ladder shall not be used in the vicinity of any electrical conductor or of any electrified equipment or apparatus if there is a danger that such use may result in any person receiving an electric shock.
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17) Personal Protective Equipment (PPE) a) General Requirement The minimum requirement for protective clothing and equipment on the project is as follows: ● ● ● ●
protective helmet protective footwear eye protection (with side shields), and appropriate industrial clothing. The protective clothing and equipment shall be correctly worn and in good condition at all times.
b) Eye Protection Eye protection shall be issued and worn by all personnel as part of the minimum site PPE requirement. Eye protection shall be selected and used according to local standards on: ● ●
“Recommended Practices for Eye Protection in the Industrial Environment” and “Filters for Eye Protectors” “Filters for Protection Against Radiation Generated in Welding and Allied Operations”.
c) Hand Protection Gloves shall be provided where an employee or other person are required to handle materials, tools, equipment or substances which could harm the hands. These gloves shall be in accordance with “Industrial Safety Gloves and Mittens (excluding electrical and medical gloves)” as per local standards. Suitable protective substances shall be provided where an employee or other person is required to handle harmful substances or agents which could cause injury or irritation to the skin. d) Hearing Protection Suitable hearing protection shall be provided and used where an employee or other person is exposed to noise which is likely to be injurious to their welfare, and which cannot be suppressed at its source to an acceptable level. Hearing protection shall be in accordance with local standard on: ●
“Acoustics: Hearing protectors”.
e) Protective footwear For most construction activities, steel capped safety boots, complying with “Safety Footwear” standards, will be needed to protect against crush injuries to the feet. In some situations, additional forms of protection against injury to the feet will be required, e.g., footwear which protects against water, chemicals, hot splashes, penetration injuries to the underside of the foot and ankle twist injuries from rough terrain. f) Protective Headwear Protective headwear ranges from industrial safety helmets for protection against impact injuries, to broad brimmed hats to protect against eye damage and skin cancer caused by exposure to the Sun. Where both risks exist, i.e., Falling objects and Sun exposure, industrial safety helmets with wide brims shall be worn. Industrial safety helmets to protect against impact injuries shall comply with local standards on “The Selection, Care and Use of Industrial Safety Helmets”. g) Respiratory Protective Equipment Suitable respiratory equipment, protective clothing and ventilation shall be provided where any impurities (e.g., gas, vapour, dust or other atmospheric contaminant) are present, cannot be suppressed at the source of emission, and are likely to be injurious to the health and welfare of an employee or other person, or are likely to produce an unsafe condition. Respiratory protection shall be in accordance with local standards on: ● ●
“Selection, Use and Maintenance of Respiratory Protective Devices” “Respiratory Protective Devices”.
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h) Safety Lines and Harnesses A safety line and harness shall be provided and used where an employee is required to work on any part of a site or structure and they cannot practicably be protected from the risk of falling by the provision of work platforms, guard rails, etc. Safety harnesses shall be selected and used according to local standards on: ● ●
“Industrial Safety Belts and Harnesses: Selection, Use and Maintenance” “Industrial Fall Arrest Systems and Devices”.
i) Elevated Work Platforms (EWP) All persons working from an EWP shall secure themselves to the attachment point on the inside of the cage with a safety harness. No person is permitted to leave an EWP at height without the permission of their supervisor who will have conducted a Job Safety Analysis (JSA) and ensured that the operator is fully aware of the safety requirements. j) Skin Protection Employers shall ensure that appropriate protection is provided for all personnel exposed to the effects of UV rays from the Sun. Supplies of sunscreen lotion shall be readily accessible for use by employees working in direct sunlight. Employees shall be warned of the dangers of exposure to UV rays and of the necessity to wear the protective clothing and equipment supplied. k) Excavation Work 1) General Reference “Advisory Standard Excavations of Australia”. Before excavation work is commenced, an engineer must assess all SITE conditions that could affect the excavation and prepare a written report on: ● ● ● ●
those site conditions recommendations as to the use of temporary support systems other forms of making the excavation safe any other matter that may be relevant to protecting the safety of persons involved in the performance of the work, or in the vicinity of the excavation.
Where excavation work has commenced, a competent person must, at least once a day, carry out an inspection to ensure that conditions at the site are safe and that the work is being performed in accordance with any relevant engineer’s report. Suitable materials must be provided and used to ensure that conditions at the site are safe and safe systems of work must be implemented. The site must be left in a safe condition when work is not in progress. Materials or spoil shall not be placed near the edge of an excavation where it is likely to cause a collapse of any part of the excavation or endanger any person in any way. 2) Access and Egress Safe and serviceable ladders, stairways or ramps shall be provided for access-to and egress-from every place in an excavation where an employee or other person is required to work. In every trench 1.5 m or more in depth, ladders shall be provided for safe access or egress. Ladders used for access or egress in a trench or excavation, shall extend from the bottom to at least 1 m above the top and shall be secured to prevent movement. 3) Barricades Suitable barricades or guard rails shall be provided as near as practicable to the edge of every accessible part of an excavation into which an employee or other person may fall a distance of l.5 m or more. A protective beam or timber baulk should be placed at the edge of those excavations where there is a risk that an item of plant may accidentally enter into that excavation. 4) Dust Control When excavation work is carried out in siliceous material, adequate precautions shall be taken to prevent the liberation of dust. The plant shall not be used for drilling, picking, scabbling, cutting or ripping of siliceous material unless fitted with a dust suppression device.
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Regular tests of the atmosphere shall be carried out to ascertain the levels of dust particles whenever excavation work is undertaken in siliceous material. When the concentration of dust particles in the atmosphere exceeds the limits set by the Statutory Authority, all work in the excavation shall cease unless effective means are provided to protect persons exposed to the hazard. Dust control strategies for employees shall be completed in accordance with the advisory standard for dust. l) Site Facilities and Amenities i) General The Principal Contractor’s employees and the employees of Subcontractors must be provided with reasonable facilities for keeping clothes and personal belongings while at work. Where the work does not require a change of clothes, the facilities shall at least consist of hanging space with provision for the safe custody of personal belongings. The type and size of the facilities shall be in accordance with WH&S regulations and workplace amenities Advisory Standard. ii) Amenities The facilities provided in workplaces must: ● ● ● ● ● ●
be hygienic and waterproof be separated from any hazard (including noise, dirt and atmospheric contaminants produced by any work process) provide reasonable facilities for washing and storing utensils contain the means for boiling water for hot drinks have refrigerated storage for perishable foodstuffs have a supply of clean cool drinking water.
The dining room shall not be used for the storage of materials and tools. The dining room may be used for meetings and training sessions with prior approval from the Principal Contractor. 3) Cleanliness All crib huts, offices and other amenities shall be maintained in a healthy, clean and sanitary condition at all times. Rubbish bins shall be kept covered and emptied daily. Sanitary conveniences and washing facilities and the floors and drains thereof shall be cleaned with disinfectant and water at least once a day. 4) First Aid The number and location of First Aid Kits will depend on the size and layout of the workplace. The Advisory Standard for First Aid details the requirements for First Aid facilities and personnel. First Aid kits and the First Aid Room shall contain appropriate supplies to cater for all hazardous substances used on the project. A First Aid attendant who holds a current First Aid Certificate shall be readily available whenever work is in progress on the site. The First Aid attendant shall maintain a “Record of First Aid / Medical Treatments” for the Project. Details of all first aid and medical treatments are to be recorded and forwarded to The Principal Contractor’s Site Manager and Senior Safety Co-ordinator each month and must be made available to the Owner Company upon request. Procedures for obtaining First Aid and medical treatment are to be posted on notice boards and included in the employee induction course. 5) Fire Prevention and Extinguishment To minimise the risk of fire in the workplace: ● Waste materials and accumulated dust shall be removed on a regular basis ● Flammable materials shall be kept and handled in a manner that reduces the risk of fire ● Fire extinguishing equipment shall be in accordance with local standards on “Portable Fire Extinguishers” and maintained in accordance with “Maintenance of Fire Protection Equipment”: – provided and located in readily accessible positions – suitable for the special risks involved, and – maintained in good working order.
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Employees shall be instructed in the use of such equipment as soon as practicable after commencing work on the project. Where possible, without endangering life, every effort shall be made to extinguish a fire outbreak in its incipient stage. If control of the fire cannot be achieved promptly, efforts shall be abandoned and all personnel evacuated to a safe area. Any fire incident, no matter how minor, shall be reported to the Site Manager as soon as possible and an investigation undertaken to identify the causal factors. 6) Emergency Procedures The procedure for evacuation of the workplace shall be posted on notice boards and included in the employee induction course. Note, the emergency assembly points are fluid based on the operations that are being completed on a daily basis. Each employee should ensure that they are familiar with “today’s” emergency assembly area. As soon as practicable after commencement of the project, a practice evacuation drill shall be carried out to determine the effectiveness of the procedures. Where the failure of an artificial lighting system at the workplace could cause a risk to the safety of persons at work, or to the safe and rapid evacuation of persons in the event of an emergency, a suitable emergency lighting system shall be provided and maintained. 7) Special Appendix: Treatment and Reporting a) Purpose To provide for a system of reporting injuries which ensures prompt and effective treatment for the injured person; and immediate and thorough investigation of the causes to prevent recurrence b) References Local government industrial rules and regulations c) Definitions ●
● ● ●
●
●
Serious Injury: where a person has suffered major trauma, is totally incapacitated and in need of immediate medical assistance. This category applies to ALL electric shock exposures Minor Injury: where a person may require medical treatment but is not severely incapacitated First Aid Injury: injury which requires simple treatment available from a standard first aid kit Medical Treatment: the issue of any medicine, drug, X-ray, etc. or treatment that cannot be sourced from a standard first aid kit Incident: any event which causes damage to property, vehicles or equipment, any unplanned uncontrolled release of energy, equipment malfunction, fire or explosion Near Miss: an event which could foreseeable have resulted in any of the above.
d. Procedure All employees who sustain any injury or suffer any illness, no matter how minor or insignificant, are to report the matter to their foreman immediately. The foreman will then arrange such treatment, transport or response as is appropriate. Serious Injury Upon notification of a serious injury including any exposure to electric shock the foreman shall: 1) ensure that the injured person is in a safe and comfortable position 2) as soon as practicable, notify their relevant Manager (within one hour) 3) notify the Senior Safety Co-ordinator of the Principal Contractor (within one hour) 4) within one hour of the accident occurring, the following shall be notified: a) Site Manager b) Project Manager c) Engineering Director. 5) When the situation is under control, immediately prepare an appropriate Incident Report and Investigation form and forward to the Site Manager (see Figures 2.7 and 2.8). All witnesses’ statements, photographs, drawings, diagrams and relevant documentation must be included. The Site Manager will forward a copy to the Project Manager who will forward a copy to the Owner Company’s representative. Minor Injury When notified of a minor injury the foreman shall:
2.2 Site Operations Manual
Figure 2.7 Incident Report – Typical form.
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Figure 2.8 Incident Investigation Report – Typical form.
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1) Upon advice from the medical personnel, arrange the transport of the injured person to the medical centre or hospital 2) Within one hour, notify the Site Manager and Site Safety Co-ordinator 3) Within one hour, complete a record of First Aid / Medical Treatment and forward to: a) Site Manager b) Site Safety Co-ordinator c) Project Manager. The Site Safety Co-ordinator in consultation with the Site Manager will decide whether further investigation is required. 4) As soon as the injured person has been treated, follow up with the medical personnel for any changes, further treatment or reclassification to alternative duties 5) If follow-up treatment is required, ensure that the injured person attends the medical centre at the appropriate time 6) When the injured person regains full health, ensure that he or she returns to the medical centre or hospital for review and return to normal classification. First Aid Injuries Where an employee sustains a minor injury, which requires minimal treatment obtainable from a standard first aid kit, the foreman shall take the following actions: 1) Ensure that adequate treatment is administered by the First Aid Attendant 2) Return employee to appropriate duties. Note: The First Aid Officer shall complete the Record of First Aid / Medical Treatment. a) Workers’ Compensation If an injured person is issued with a Workers’ Compensation Certificate, ensure that both copies are handed in, that is, the Employer’s and Worker’s copies. These are to be handed in to the Site Administrator, who will arrange for the injured person to complete the appropriate claim form. b) Major Accidents and Near Misses All major incidents and near misses must be reported immediately to the relevant Foreman. Upon being informed of a major incident or near miss, the Foreman shall: ● ●
Advise the Site Manager immediately Within one hour, advise the Project Manager and Owner Company representative.
A full investigation is to be carried out immediately by the Foreman and Site Safety Co-ordinator. Note: The Site Safety Co-ordinator will consult with the relevant Site Manager and will make a decision on whether to carry out a full investigation. e) Forms to be filled in Given below are typical blank forms. These forms are required to be filled in and submitted in the event of an accident. f) Clearance Certificates ● No work on site can be commenced without an appropriate Clearance Certificate from the Superintendent ● Either the Owner Company Site Manager or their nominee can request a Clearance Certificate ● All precautions indicated in the Clearance Certificate should be strictly observed ● All Clearance Certificates have an expiry period. In case work needs to be carried out after this expiry period, then the existing Clearance Certificate will need to be extended or a fresh one issued in its place ● The onus for handing over a plant safe for construction activities rests with the Owner Superintendent ● Clearance Certificates will be needed for work that will be handled by Subcontractors ● In case the Owner does not have appropriate Clearance Certificates to cover for the types of work that the Owner Company intends handling, it is suggested that the Owner Company use their own Clearance Certificates and get them approved by the Client ● The Clearance Certificate will need to be displayed at the place of work
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The Construction Manager assigned Team Leader for Clearance Permits will be responsible for obtaining the Clearance Certificate and ensuring that its conditions are followed.
g) Site work Clearances and Permits Refer to Chapter 6 for procedures to be followed and suggested Clearance Certificate forms.
2.3 Site Administration and Cost Control 2.3.1 Plans and Schedules The Contract documents always have a milestone chart indicating target dates to be achieved by the Owner Company for key activities. Penalties may be incurred when these dates are violated. Based on this, the Project Manager prepares a more detailed schedule for the entire project. This document is used as a reference document for monitoring the project progress. The schedule would indicate a few key dates to be met during the installation and commissioning phase of the project. The Site Manager, usually, prepares a detailed schedule for the installation and commissioning phase of the project. This schedule takes into account the following: ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●
Dates by which a clear site will be available to carry out prescribed / allotted work Arrival of documents and software to site after the FAT List of activities to be performed Estimate of duration of activities Resource requirements (men and material) and their availability Resource capabilities Constraints Calendars Dates and days of working Hours of working Number of teams to work Number of shifts planned to work Assumptions Leads and lags Work that can be done preparatory to a shutdown, if any.
For major shutdowns, a separate schedule would be prepared called “Shutdown Schedule”. This schedule will be used as the key document for monitoring the progress of the site work. A copy would be made available to the Subcontractor to enable them meet the target dates. Another copy should be sent to the Project Manager to enable them track the progress. Delays likely to affect the Owner Company meeting their target dates will be known in advance so appropriate actions can be taken.
2.3.2 Materials Management and Storage Materials management and storage is for all Equipment, Hardware, Software and Spares. 2.3.2.1 Goods Receipt ●
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All equipment meant for the project is eventually sent to site. This includes items ordered by the Owner Company design group (cubicles, marshalling panels, system items, spares, cables, pipes, fittings, etc.) and those supplied by Subcontractors. At times, items such as hardware storage devices, etc. are sent by post or courier. Material purchased locally by the Site Management will also end up on site On receipt on site, they require checking and inspection. Checking is done to ensure that the correct items and quantities have been received on site. Inspection is done to ensure that the items have reached the site without damage. Checking with Data sheet for physical details, model number if any, etc., Positive Material Identification (PMI) tests on materials to analyse and identify the material grade and alloy composition for safety and quality control are typical checks and inspection
2.3 Site Administration and Cost Control ●
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When wrong items are received on site (i.e., digital input card received in place of an analogue input card), the sender will need to be informed urgently One of two possibilities exists when lesser quantities are received. (a) Short shipment from the sender (b) Lost in transit. Insurance claims might be involved in the latter case Once again, an insurance claim might be involved when equipment arrives on site in a damaged condition. Within three days from the date of receipt of goods on site, checking and inspection should be completed A register should be maintained on site to record the inward / outward movement of all goods This register should clearly indicate: date of receipt, the purchase order number, brief description of item, sender details, quantity received, quantity ordered, delivery notification details, test certificates, manuals if any, notification details on short shipment, damaged items (if applicable) Bin or shelf reference within the store where the item is kept should also be recorded. Where applicable, the Tag number in the plant section where the instrument will be installed will also be recorded (this will enable traceability) Date of goods issued, quantity withdrawn and the name of the person who authorised the issue will also be entered in the same register A Site Engineer’s assistance will be needed to carry out checking / inspection All electronic and digital equipment will need to be stored in a safe and dry location. They are best kept stored in the boxes that were used for their shipping Items such as CDs, USBs and documentation such as User Manuals are often shipped along with the system. Descriptions of such items and quantities should be noted in the “Inwards Goods” register. After that, these items should be handed over to the Site Engineer for safe custody.
2.3.2.2 Goods Issue
1) When goods are moved from the store, a material withdrawal form will need to be filled in and approved Only authorised personnel approve the material withdrawal form. The Site Manager will issue the names of the authorised people 2) Subcontractors are not authorised to approve the form to withdraw any material from the store. Their request will need to be authorised by approved persons 3) Once the goods have been withdrawn, the stock will be updated 4) It is important to note that at the project handover to or at the time of commissioning for plant custody, a material reconciliation exercise is carried out; therefore, maintaining accurate updating is of high commercial importance. 2.3.2.3 Spares
Among the materials stored at the site store, spares will need to be treated separately for various reasons: a) Most likely they will lie in the store for a long time b) Electronic spares may have a special H/W and S/W version number. This might need to be verified or even upgraded before installing on the system c) Someone has to specifically inspect and ensure that it is in working order. Otherwise, one may have an unpleasant surprise d) In general, the Owner Company will be required to supply a specific quantity of spares. e) If spares are consumed to replace items that failed during commissioning, then the Site Manager will need to get them replaced. f) The Site Manager’s authorisation will be needed to withdraw spares from the stores g) Spares will need to be fully protected and stored separately at dry location h) A separate register should be maintained for spares i) Serial numbers and version numbers of all spares must be recorded in the register j) A very important distinction is made regarding spares for various purposes. A. Maintenance spares (usually stored in a common warehouse by the Contractor until handover but sign-off required by the Plant Owner). These spare parts are the parts required for the two-year period of normal operation of the supplied systems. The period of coverage might be further extended up to five years at the Owner Company’s sole discretion B. Construction spares (for Contractor supply and use) may be bought out or handed over to the Owner Company on handover of site and generally they are once-through non-metallic consumables like O-rings, gaskets, etc.
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C. Pre-commissioning and Commissioning spares (usually lumped together as main team members are commonly represented). These spare parts mean the parts required during the start-up and commissioning period, which in consequence shall be available at the Work Site prior to the supplied systems being put into operation D. Hot Spare facility is a facility used for hot testing of spares, training and simulation. It shall comprise a rack complete with Main Unit(s), power supply, I/O, bus, communication modules and peripherals, of the same model / parts number as the supplied equipment and system components. This Assembly will be located in the Owner Company’s maintenance shop and normally powered but managed by the Contractor until handover Bonded Spares Facility siting is sometimes requested by the Contractor from the Owner, free of charge, with free access to the inventory and restocking of the store, subject to mutually agreed rules of use and access. 2.3.2.4 Software
i) Software arrives on site in different mediums. Sometimes, it arrives by an e-mail. The Site Engineer then copies it on to a Hard disk ii) Software is there for different purposes. Documentation comes by CD or suitable memory device – some suitable for running various workstations CD or suitable memory device. Configuration files and version upgrades are often sent by Hard disk or a suitable mass-memory device. Databases also arrive on a different disk iii) All software should be handed over to the Lead Site Engineer for verification and safe storage. These will be kept in appropriate enclosures and stored in locked cabinets iv) Date of arrival and version numbers should be marked on each disk or memory device on arrival v) An up-to-date register should be maintained on site of all software, including those that will be eventually be handed over to the Client vi) An up-to-date register on system items with details of software loaded and software version number it is running should be maintained on site. Disks / Memory devices containing obsolete versions of all software should be destroyed. 2.3.2.5 Site Purchase
A number of Installation materials are often purchased from Site. This should be done by using a “Site Purchase Requisition” or SPR form. A typical SPR form is provided in Chapter 6. All purchase requisitions should be approved by the Site Manager. The authorised limit for the Site Manager is set by the Project Manager and based on size of project. In some companies and in certain types of contracts and large plants, the SPR is arranged later to be integrated with the Spare Parts Interchangeability Record (SPIR). These days, both of them are generated using “SAP” or equivalent asset management software.
2.3.3 Staff Management 2.3.3.1 Site Organisation Structure
Human Resource Management includes the processes required to make the most effective use of people involved in the site activity. A variety of people gather on site to complete the Installation and Commissioning of the plant, e.g., direct Contractor staff, temporary / Contract staff, consultants and Subcontractor staff, not to mention Project Management Consultants (PMCs) / Owner representatives. The temporary nature of the project means that the personal and organisational relationships will be both temporary and new. The site Manager should be able to select techniques that are appropriate for such transient relationships. Organisational planning involves identifying, documenting and assigning site roles, responsibilities and reporting relationships. The site organisational structure is tightly linked with the communication structure. This should be planned and announced as early as possible. This is essential so that the Client, the Subcontractors and others at the Design Office know who is doing what. 2.3.3.2 Site Working Hours
All staff have to fill in timesheets. Refer to Chapter 6 for normal working hours for the site is 8 hours per day and 48 hours per week (6 working days per week). The Engineer in Charge of Subcontractors will monitor the working hours of Subcontractor staff. Depending on the urgency and workload, the Site Manager may ask their staff to work extended hours. Such overtime work will be controlled on a need basis. Working of overtime will need to be approved by the Site Manager. Proforma of a timesheet is to be used.
2.3 Site Administration and Cost Control
The Site Manager may also request their Subcontractors to work extended hours and holidays to meet the plan / schedule. 2.3.3.3 Charge Numbers For Site
The Site Manager, in consultation with the Project Manager, will issue a set of charge numbers to be used by staff on site. The charge numbers will closely line up with the cost centres that are being used by the management for cost monitoring and control purposes. All major cost centres will have budgeted hours and actual hours available for comparison purposes. 2.3.3.4 Applying for Leave
The Contractor Company’s direct employees working on site will use the leave application form being used by the home office. Staff intending to take leave for a week or longer will need to give adequate notice. All leave application forms arising on site will be approved by the Site Manager. Part-time / Contract staff / key Subcontractors intending to take holidays for more than three days will need to give adequate notice to the Site Manager. 2.3.3.5 Travel for Staff on Site
Direct employees working on site will use the home office “Domestic Travel- Approval and Reservation Request” or such form for all business travel. The Site Manager will approve the travel form. A separate charge number will be raised for travel by site staff and all travel charges will be charged against this charge number. As stated earlier, the Project and Site Manager can then compare the budgeted cost to that actually incurred on the project. 2.3.3.6 Discipline on Site
All site staff shall conduct themselves in a responsible way at all times as they work closely with the Client. Any staff behaving in a way that will bring disrepute to the Contracting Company should be discharged instantly from the site. 2.3.3.7 Performance Review for Staff On Site
Performance reviews for direct Contracting Company staff will be performed by the Project Manager and submitted to the Head of the Contracting Company for approval. Performance review for the Site Manager will be conducted by the Head of the Contracting Company. 2.3.3.8 Staff on Temporary Transfer to Site
The Contracting Company directing staff, being sent to the site for periods longer than one month, will be addressed separately by the Manager they are reporting to, with the additional inputs received from Site Manager / Project Manager.
2.3.4 Site Administration and Cost Control The SITE is one of the major cost centres for the project. It is essential that strict cost control measures are put in place right from the early stages of site establishment. Strong Owner presence, tight schedules and a little poor planning, at times, induce the Managers to get the job finished at any cost. Sensible site administration could convert these threats into opportunities. 2.3.4.1 Site Cost Monitoring
Site costs must be carefully monitored before they can be controlled. A set of charge numbers must be raised to which costs incurred may be charged. The budgeted cost for these items must be known. A spreadsheet “Site Report” format is required to lodge all site costs. The spreadsheet has links and it will plot the “S-Curve”. A copy of this should be sent to the Project Manager as part of the monthly report. 2.3.4.2 Site Cost Control
The Site cost management and control include the processes required to ensure that the project is completed well within the budgeted costs.
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Cost control is concerned with: ● ● ●
Influencing the factors which create changes to the cost baseline to ensure that the changes are beneficial Determining that the cost baseline is changed Managing the actual changes when and as they occur.
In managing costs, the Site Manager may take into account the following: ● ● ● ● ● ● ● ● ● ● ●
Cost baseline Monitoring cost performances to detect variances from the baseline Resource requirements Resource rates (including Subcontractors) Activity duration estimates Days, dates and hours planned to work Change requests Prevent incorrect, inappropriate and unauthorised changes from being included in the cost baseline Site activity schedule Lessons learned Cost Management plan. The Site Manager should keep the Project Manager informed of the cost changes being incurred.
2.3.4.3 Revised Cost Estimates
A revised cost estimate is the forecast cost information to complete the project. If the revised cost is estimated to go over the baseline cost, a detailed explanation giving the reasons, the assumptions made and a plan to recover the cost should be sent to the Project Manager. Revised costs do not mean revised budgeted costs. It may be an increase or decrease. Increased scope or decrease in quantities may also be a reason for revised cost estimates. 2.3.4.4 Budget Updates
Budget estimates are a special category of revised cost estimates. Budget updates are changes to an approved cost baseline. These numbers are, generally, revised only in response to scope changes. In some cases, cost variances may be so severe that “re-baselining” is needed to provide a realistic measure of performance. The Project Manager is the only person authorised to change the cost baseline. 2.3.4.5 Corrective Action
Corrective action is anything done to bring the expected future project performances into line with the project plan. Cost blow-out forecasts must always be accompanied with “Corrective Action” plans. 2.3.4.6 Estimate at Completion (EAC)
An estimate of at completion (EAC) is an estimate of (a) Forecast date for Project Completion and (b) Forecast cost to complete. 2.3.4.7 Lessons Learned
The causes of variances, the reasoning behind the corrective action chosen and other types of lessons learned from Cost Control should be documented, so that they become part of a historical Database for future use.
2.3.5 Subcontractor Management It is common to sub-contract a portion of the site work to Subcontractors. Generally, a specification for the sub-contract is written by the Project Manager for work to be performed by the Contractor. From among the bidders, one is selected. Invariably, it will be a back-to-back contract, with performances, completion dates and penalties imposed on the Contracting Company being passed on to the Subcontractor. For the Client, the Subcontractor is no different from the Contractor and shall consider them to be part of the Contractor.
2.3 Site Administration and Cost Control
The Subcontractor has to be advised to note and record the variations, delays, etc. and submit to the Contractor to take up with the Owner, as they are also eligible for such claims from the Contractor. 2.3.5.1 Subcontractor Check List
The Management of Subcontractors involves the following: ● ● ● ● ● ● ● ● ● ●
Ensuring that a timely and orderly site mobilisation occurs Ensuring that they have the right skill and sufficient workforce to handle the job Have the right tools in adequate numbers to handle the job Have experienced people on the job (not learning at project cost) Have fully understood the details of the job on hand Have prepared a detailed schedule to handle the job Have a disciplined workforce Have a safety-conscious workforce Have skills and experience and know how to deal with the Owner Have enough backup resources to handle emergencies.
2.3.5.2 Obligations to the Subcontractor
Contractors also have some obligations to Subcontractors, which will enable them meet their targets. ● ● ● ● ●
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Ensure that the Contractor hands over all appropriate drawings, manuals, Databases, etc., as per agreed scheduled date Ensure that the Subcontractor gets a clear site to work on as per the scheduled date Ensure that the Subcontractor gets the necessary clearance certificates on site to proceed with their work Ensure that changes of plan are communicated to the Subcontractor without any delay to enable them plan alternatives Make sure that there is no confusion between the Contractor and the Subcontractor in relation to the procedures to be followed and plans of action. Both work as a single team Agree on how many days of advance notice is needed for resource changes and ensure that it is given.
2.3.5.3 Subcontractor Supervision
Subcontractors have their own supervisors to manage their resources and activities. However, Contractors have to ensure that they handle their jobs efficiently, timely and in a safe manner. Hence, there are benefits in getting one of the Senior Site staff of the Contractor to supervise all Subcontractors. The assignee would supervise their discipline, safety in work, start and stop hours, claims, etc. However, on technical matters, the Subcontractors may respond to Lead Engineers. 2.3.5.4 Quality in Work
The Contractor has to ensure that the quality of work performed by Subcontractors is of a high standard. Quality should be built into the work as they perform it, not arrived at through a series of rejections. This latter course will delay the job. This should be made clear right in the early stages of the project. Quality work includes preparation of appropriate documentation, e.g., producing test results, marking up of changes made on drawings, etc. 2.3.5.5 Morning Meetings
The Subcontractor’s Lead Engineer should attend the daily progress meetings held by the Site Manager or their representative. As indicated elsewhere, the topics discussed at the meeting will cover, among other things: ● ● ● ● ● ●
Overall progress against planned target Progress made the previous day Delays caused Bottlenecks Potential problems foreseen Resource status (men and material).
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2.3.5.6 Delays Caused by the Subcontractor
Delays caused by the Subcontractor, which have the potential to prevent meeting the target dates, should immediately be brought to the attention of: ● ● ●
Site Manager Project Manager Subcontractor Head.
A corrective action plan to bring the project back on track should be arrived at in consultation with the above three persons. Estimated costs for such actions should be evaluated by the Site Manager and approval sought from the Project Manager. A plan action of action to be taken with respect to the Subcontractor should be formulated and implemented. 2.3.5.7 Breach of Contract by the Subcontractor
Breach of Contract from the Contractor’s Subcontractor is a serious issue. With good Site Management, it would not have come to such a serious stage. At least, the warning signs would have been there for some time. The Site Manager in consultation with the Project Manager and the Head of the Contracting Company should draft a plan of action to deal with this issue. 2.3.5.8 Subcontractor Safety
The Contractor has the responsibility for the safety of Subcontractors working for them as their own staff and workforce. All the precautions taken and procedures followed by Contracting Company staff while working on site would also be applicable to Subcontractors. The Lead Engineer from the Subcontractor shall attend all safety meetings conducted by Contractor. 2.3.5.9 Claims by the Subcontractor
The Subcontractor in the process of execution may submit a variety of claims. The Site Manager should have well defined and streamlined processes and procedures to handle these. 2.3.5.10 Progress Payment Claims
The Subcontractor would be raising invoices for progress payments. A well-defined procedure for processing these should be instituted. A separate register should be kept for the invoices made and their status. 2.3.5.11 Delay Claims
The Subcontractor could issue a delay notice. This would be in respect of: (a) Information / Data / Equipment not supplied by the Contractor as per schedule (b) The site not ready for installation / commissioning as per schedule (mostly due to the Owner being delayed). In all cases, these notices will lead to: (a) notice for Extension of Time (EOT) claim (b) Cost incurred by the Subcontractor due to these delays. The Contractor has to respond to these claims within a nominated period and these issues have to be resolved with the utmost urgency. The Site Manager should put in place a procedure to handle such claims. A register should be maintained to indicate claims made and their status 2.3.5.12 Extension of Time Claims (EOT)
Extension of time is claimed based on the delay notices served. Once again, these are serious, like the delay notices. They should be handled with the utmost speed. The Site Manager should put in place a procedure to handle such claims. A register should be maintained to indicate claims made and their status.
2.3 Site Administration and Cost Control
2.3.5.13 Dealing With the Client
The Owner / Client is the key stakeholder and “Client satisfaction” should be the motto that should pave the way for further projects with them in future projects. The management of Owner expectations may at times be strenuous with differing views and working for the benefit of the project is a major challenge for Contractor Site Management.
2.3.6 Role of the Site Manager The role of the Site Manager should be as a: ● ●
Manager Leader.
As a Manager, he will be responsible for producing key results expected by the Contractor Management (i.e., their Company), a successful project well within the budgeted cost and Schedule. As a Leader he will be: ● ● ● ●
establishing direction aligning people motivating and leading the team to reach targets managing the Owner and influencing their expectations / decisions for the benefit of the project.
2.3.7 Documents and Records On Site For the successful operation on site, it is absolutely essential to maintain and keep up to date some key documents and records. These are indicated below. 2.3.7.1 Engineering Manuals
All operating, installation manuals, brochures of all instruments, equipment and all accessories supplied by Contractor and other vendors are to be made available on site, in adequate numbers, for reference as well as for installation, calibration and commissioning purposes. 2.3.7.2 Engineering Drawings and Database
A lot of changes will occur during the course of execution of the project and commissioning. All drawings and other documents are be recorded / updated in the Master Drawings / Database, as and when a change occurs. Recordings are to be distinctly distinguishable and the drawings maintained as “Master Drawings”. Changes in the Master Database maintained at the home office should be made forthwith, on a weekly cycle basis as backup. An alternative practice has been found to be more satisfactory while commissioning plants with a large Database. The Master Drawings / Database is shifted to site. Changes in Database / Interlocks will be updated, as and when they occur, during commissioning. The Project Manager will be informed once a week about the changes. Revised CAD drawings should replace the hand-marked drawings as soon as possible. 2.3.7.3 Registers / Files to be Maintained On Site
A number of suggestions have been made on Registers to be maintained on site. A summary is given below. 2.3.7.3.1 General ●
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Attendance Register: To indicate who is in and working somewhere on site or outside for site works like follow-up inspection, etc. Visitors Register Travel Register.
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2.3.7.3.2 Contract Related ● ● ● ● ● ● ● ●
Telephone conversations with the Client Meetings with the Client Approved Drawings / Documents / Data received from the Client Delay notices issued on the Client EOT claims on the Client Drawings / Documents / Data sent to the Client Weekly / Monthly / Quarterly Project reports Invoices / bills raised on the Client.
2.3.7.3.3 Subcontractor Related ● ● ●
Free Issue items handed over to the Subcontractor Progress Payment claims made by Subcontractor Delay notices issued by Subcontractor.
2.3.8 Drawings / Documents / Manuals Issued to Subcontractor 2.3.8.1 System Related ● ● ● ● ●
Register indicating H/W location, Cubicle number, Serial number, Version number, Software version number Items for which S/W upgrade was done and the date when carried out Spares Register (includes those issued in an emergency and expected to be replaced) Site Incident Report (SIR) and their status Owner Work Requests and their status.
2.3.8.2 Software on Site ●
List of Software on site and their version numbers.
2.3.8.3 Material Management Related ● ●
Register for Inward / Outward movement of goods Register of equipment sent for repair and / or re-calibration / certification, etc. and when expected back.
2.3.8.4 Safety Related ● ● ● ●
Material Safety Data Sheets (MSDS) List of Hazardous chemicals kept on site Incidents on site (Major, Minor, Near misses) Safety meeting reports.
2.3.9 Overseas Construction Sites (Middle and Far East) Construction sites located overseas require a special mention. To start with, the Site Office is far away from the Design Office and what can be usually sorted out in a couple of hours will take days. Also, overseas sites differ in many ways from sites located within the base country. Some of the key areas of difference are: ● ● ● ● ● ●
Communication problems Work cultures Local laws / Codes of Practices will apply, which may be significantly different to those within the same country Some or same skill sets may be difficult to hire Skill levels Productivity
2.3 Site Administration and Cost Control ● ● ● ●
Subcontractor management Currency Time zone differences Infrequent travels / visits.
All these will eventually impact on the project cost and the effectiveness of site Management. Allowance must be made in the estimates for site Operations. The gain in currency cross rates may be more than lost in other areas. From experience, it appears that: a) b) c) d) e)
Approvals for variations are more difficult to obtain Multinationals are expected to meet the Contract requirements more rigidly compared to the local companies Demand for a higher quality of engineering Accidents attract, apart from severe penalties, greater publicity Higher demand to meet the target dates.
Many of these are applicable to local projects too but the effect is heightened for overseas projects. In view of the above, the Contractor may have to get more closely involved and drive the Site Management. Employing a Subcontractor to manage sites overseas may not be the best option. Once again, from experience, a more streamlined Site Management with predictable outcomes may be obtained by using more printed formats and visible targets (checklists, Data sheets, questionnaires, etc.) as opposed to oral communication. A stable skill base goes a long way to project success.
2.3.10 Communications and Reporting 2.3.10.1 Language Parlance
In the common parlance of project constructions in Process Industries, the following English language use is common. Generally, all technical documents that have a legal implication in form of duties, responsibilities, services and commercial cost implications, etc. are required to follow the language connotations without fail. Some or all listed below may be found in Contract documents: ●
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“Will”: is used normally in connection with an action by the Owner and / or nominated representative, rather than by a Contractor “May / Can”: is used where alternatives / action are equally acceptable “Should”: is used where provision is preferred “Shall”: is used where a provision is mandatory by this specification, a strongrecommendation “Must”: is used where a provision is vital, as it signifies a legal or statutoryrequirement, suggesting an absolute obligation to comply.
2.3.10.2 Types of Communication
Communication involves exchange of information. There are many types: ● ● ● ● ● ● ● ●
Internal within Contracting Company With Subcontractors Formal Informal External With Client With Vendors With regulating authorities.
Communication may be classified in different ways: ● ● ●
Oral In writing Informal memo
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E-mail Fax Formal report Video: webinar, Zoom, etc.
The Site Manager and their staff will decide the mode and media for communication. The Contractor will deal with the Formal reporting that has to happen between the Site Manager and the Project Manager on progress-related issues. It must be noted that these are routine reports. The Site Manager will discuss and agree with the Project Manager the dates for their submission. The reason for this is that the Project Manager in turn has to prepare and submit their own reports to the management as per scheduled dates. 2.3.10.3 Fortnightly Events Report
The Site Manager will submit a Fortnightly Events report addressed to: (a) The Project Manager; and (b) Head of Contract Company. This will highlight important events of the previous fortnight and those expected in the next fortnight. 2.3.10.4 MPR and S-Curve
The Site Manager will submit once a month a “Monthly Progress Report (MPR) with an SCurve” to the Project Manager, with a copy to Head of Contractor Company. The spreadsheet is available on PC display with appropriate links. The spreadsheet needs to be slightly modified to customise it to the project on hand. The Site Manager will submit once a month, a report on the variations claimed and their status. 2.3.10.5 SIR and CWR
SIR refers to Fortnightly Report on Site Incident Report and CWR to Customer Work Requests. The Site Manager will submit once a fortnight, the status of Site Incidences and Customer Work Requests. In the case of SIRs, it will indicate the total number, the numbers resolved and the target for the next fortnight. In the case of CWRs, the number issued and the numbers accepted as variances will be highlighted. 2.3.10.6 Safety Report
The Site Manager will submit once a month, a report on Site Safety. This will give brief details on incidences that occurred on site.
2.3.11 Project Completion and Closure 2.3.11.1 Check List for Project Closure
Project completion is an administrative closure for the project. It involves: ● ● ● ● ●
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Verify that all work (as prescribed in the Contract and subsequent variations) has been completed Correctly and Satisfactorily Verify that all payments have been completed (to Contractor Company and to Subcontractors) Update Punch List (discussed in detail with Forms on specific plant I&C works) Update records to reflect final results Verify whether the Contract Terms and Conditions prescribed specific procedures for Contract Close Out. Ensure these have been satisfactorily done Prepare a complete set of indexed records for inclusion in the Contract File.
2.3.11.2 Formal Acceptance of Closure
The requirements for the formal acceptance and closure are usually defined in the Contract. The person or Organisation responsible for Contract administration should issue a formal notification indicating the final acceptance of the project.
2.3.12 PMC / Owner – Roles and Responsibilities 2.3.12.1 Data Sharing
The Owner is responsible for sharing precise data in construction tenders.
2.4 Site Work Clearances and Permits
For example: a proper I/O count in a tender with rate Contract for increase / decrease above 5% is a fundamental responsibility of the Owner. Most Owners circumvent this responsibility by devolving on a count by the Contractor and providing inadequate base documents. 2.3.12.2 Legal
Legally, the Owner responsibilities are seen as: 1) Time-Related Compensation / Negotiations for delay in work must be resolved urgently. Delay in work due to details not provided, approvals not timely provided and suspension of work by the Client are usual issues that require prompt rectification 2) Cost-Related Related to payments of Running accounts. Cash flow is very important to a Contractor and the Client must recognise this. Escalation of rates, deviation in quantities / specifications, deduction of penalties / recoveries, etc. are often seen as common issues on site 3) Quality-Related Differences in interpretation of the Contract to be quickly resolved by negotiations. Quantity audit is critical and differences in interpretation of Bill of Quantities is an issue that requires Owner vigil. Work not conforming to specifications is often the main Owner complaint seen, so the Owner employs a Project Management Consultant (PMC) to audit QA/QC on a daily basis 4) Notifications to Authorities Notifying the relevant enforcing authority of certain projects (where notifiable) promptly is Owner Responsibility unless it is devolved to the Contractor and accepted by authority 5) Responsibility In an EPC contract, the Contractor takes on more risk, so it may cause an increase in costs to account for their increased level of responsibility. The Client loses involvement in the design process or is legally considered intrusive, so the Owner generally involves a PMC to expedite such issues on a day-to-day basis. The Owner must ensure that the PMC does not delay the project 6) Financial Guarantee The Client usually takes financial guarantees such as Performance Bank Guarantee (PBG), which varies but mostly at 10% of the Contract price, bank guarantee for Defect Liability Period (DLP), which varies from 5 to 10% of the total Contract price and few other warranties from the Contractor. This helps in reducing the financial risk to the Client but it increases the financial burden of the EPC Contractor. A failed EPC Contract due to Client delays is often cited as a major issue.
2.4 Site Work Clearances and Permits 2.4.1 Introduction a) Purpose Site Work Clearances and Permits to Work are important issues on any site and so it is necessary to define the process by which such clearances are issued and managed by a procedure b) Scope This procedure applies to all construction and remedial work within the project, unless exempted by the Site I Project Manager c) Definitions ● ●
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Authorised Issuer: a person authorised by the Client’s Superintendent to issue clearances and / or permits Clearance to Work: formal, written clearance authorising construction or remedial work to proceed. No work can be undertaken without a valid Clearance to Work Clearance Log: log maintained by the site Manager recording the scope, limitations, period of validity and conditions of their authorisation Responsible Manager: the Owner’s Project Manager or Nominee such as site Manager, Engineer, Supervisor, Engineer responsible for supervising the works. Supervision may be from a Contractor or a Subcontractor
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Work Permit: formal written permit authorising particular types of work or particular activities. Work Permits are not valid without a valid Clearance to Work covering the overall scope of work and responsibilities Authorised Issuers (Client’s Superintendent) shall be responsible for ensuring that health and safety requirements specified on Clearance Certificates are appropriate to the tasks being undertaken Supervisors are responsible for ensuring that they obtain a Clearance Certificate when required and for ensuring that their personnel working under the clearance follow the specified precautions The Safety Advisor is responsible for ensuring that Clearances remain current and the Authorisation Log is updated in a timely manner and records are filed.
2.4.2 Clearance Requirements 2.4.2.1 Clearance to Work Certificate
This certificate is issued to cover: ●
A defined scope of work within a particular zone, which may run for several days or weeks.
2.4.2.2 Types of Permits
Generally, work permits are issued for the following activities: ● ● ● ● ● ● ● ● ● ● ●
Confined Space Entry Heavy / difficult lifting Isolation Permit Hot Work High Voltage Permit: only Authorised Government Trade certified Engineer Excavation Personnel Cage Road Bridge Access Road closure permit General permit not involving any hot work Vehicle entry permit.
For the above work activities, the Clearance to Work may define that: ● ● ●
A Work Permit is required before the work can proceed The Contractor’s own permit or safe work method is acceptable The work is not allowed. Owner permits are also there where finally approved, as in existing plant battery limit cross-overs.
2.4.2.3 Work Requiring a Clearance to Work
All construction work within the project requires a valid Clearance to Work Certificate before work can commence, except for: ● ●
Work within an established workshop Work specifically exempted by the responsible Manager (generally, no exceptions. Even to carry out a wiring modification inside an office building, a permit is required where the Owner may be the Contractor, but a provision is kept for a dire emergency).
2.4.2.4 Requesting a Clearance to Work
The Supervisor shall submit a request to the responsible Manager or delegate containing at least the following information: ● ● ●
Scope of work for which clearance is requested Work method statement(s) for the scope of work Any Job Safety Analyses required.
The request shall be submitted at least 24 hours prior to the time the work is planned to commence. All Clearance to Work requests are to be submitted to a responsible Manager.
2.4 Site Work Clearances and Permits
2.4.2.5 Issuing a Clearance to Work
Clearance to Work Certificates shall only be issued by an appropriate Authorised Issuer. The following notes apply to completing the Clearance to Work Certificate (copy attached in Chapter 6). Section 1: Contract Details, Duration of Work The Authorised Issuer shall ensure that the top section of the Clearance is filled out clearly Section 2: Description of Work The Authorised Issuer shall ensure that the description of the work, nature of hazards and (general) precautions to be taken are completed in conjunction with the Supervisor. Detailed information, such as a Work Method Statement, shall be attached (if applicable) Section 3: Owner’s Clearance The Authorised Issuer shall then determine if any additional clearance from the Owner is required. If so, the Authorised Issuer shall assist the Supervisor to obtain the Clearance. The Owner clearance number shall be entered on the Clearance to Work Certificate before it is issued Section 4: Type of Work Allowed and Permit Requirements Define what types of specific work activities may be performed under the Clearance ● ● ● ●
If the work IS NOT allowed, circle NO and / or cross out YES If the work IS allowed, circle YES and / or cross out NO Insert name / abbreviation of Subcontractor if the Subcontractor’s own system for permits is to be used for the work Insert “JSA (Job Safety Analysis)” if the Supervisor can undertake the work without a permit after completing a JSA.
If there are specific Owner or relevant authority requirements that must be followed in addition to the above, they are to be indicated. A Permit course shall be arranged by Owner. It shall be for permit raisers as well as receivers, Permit authorisers and for Permit approvers. On satisfactory fulfilment of the course, a certificate shall be issued. The Site Manager should decide the persons who should attend the course. Normally the Permit raisers / receivers shall be from Subcontractor. Authorisers shall be from Contractors. Approvers are normally the Owner and in few cases some from Contractors for their own building related works Section 5: Authorisation Once the Authorised Issuer is satisfied that the Clearance is in order and that the Supervisor understands the scope of work permitted under the Clearance, he or she shall complete the Authorisation section Section 6: Acceptance This is to be signed by the Supervisor who will be directly responsible for supervising the work to be undertaken Sections 7 and 8: Hand Back and Cancellation When the work is finished, the Supervisor shall return the permit to the Authorised Issuer and sign under Section 7 to signify that the work group has left the work area. This is required at the end of the job only, not at the end of each shift. The Authorised Issuer shall then inspect the work area and upon satisfaction shall sign in the cancellation column and close. If the Authorised Issuer is not satisfied, he or she will direct the Supervisor to undertake any remedial or clean-up work necessary. Such work shall be under Clearance where appropriate. 2.4.2.6 Changes to Scope of Work
The Authorised Issuer and Supervisor shall review the Clearance during the works to ensure any changes to working conditions that may affect work are noted on the Clearance and Job Safety Analysis’s / Permits and Work Methods statements are updated to reflect those changes. The Authorised Issuer may update the existing Clearance for changes or cancel the clearance and issue a new Clearance to work. If a Job Safety Analysis (JSA) has been prepared by the Supervisor and relevant work group to cover any specific work activity allowed under the Clearance, the Authorised Issuer shall review it and attach it to the Clearance. The Authorised Issuer may require the JSA to be re-done or refer it to the Safety Adviser for advice if he or she is not fully satisfied with its scope, content or quality.
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2.4.2.7 Authorised Issuers
Authorised Issuers shall be authorised in writing by the Client’s Superintendent. The Superintendent shall satisfy themselves that the candidate is suitably trained, experienced and responsible to fulfil the role of Authorised Issuer before signing the authorisation log. The authorisation log shall state: ● ● ● ●
The name and position of the person authorised The area(s) that they may issue Clearances in The limitations on work types, permits if any The period of validity of the authorisation (maximum two years).
2.4.2.8 Documentation
The original copy of the Clearance to Work Certificate shall be kept by the Supervisor / Team / Crew Leader who accepted the Clearance. ● ● ● ● ●
Each clearance shall be uniquely numbered to allow traceability The Applicable Zone and Area Number (Z001/A002 typical) must be entered to the relevant Clearance A copy shall be kept with the Authorised Issuer from which the Clearance was issued All closed Clearances and associated attachments, including permits, shall be filed by the Authorised Issuer The authorisation log shall be available for inspection by any person who may be working under a Clearance issued by the Authorised Issuer.
The following forms are included under Chapter 6: i) Clearance to Work and Permit Flow chart ii) Clearance to Work Certificate iii) Clearance Log iv) Road / Bridge Access Permit v) Excavation Permit vi) Confined Space Permit vii) Hot Work Permit viii) Crane / Forklift mounted Personnel Cage Permit ix) Isolation Permit x) Field Instrumentation Permit xi) Work on Monitoring and Control Signals Permit – usually for building access control systems, say for CCTV surveillance.
2.5 Planning, Scheduling and Cost Control 2.5.1 General Generally, Planning, Scheduling and Cost Control are run as a single segment works / software at the home office and divided into many stages of a project such as Basic engineering, Detailed engineering and Site Construction Management, etc., if run on complex software such as Primavera (current version is P6). However, the most common practice is to divide Planning, Scheduling and Cost into two segments – Home Office and Site Office. However, integration and reporting is from the Home Office. It should be noted that this is a very important pillar-activity in Project Management and critical in Construction Management. Reporting progress, budgeting, invoicing and costing details are also part of the activities.
2.5.2 Introduction to Planning 2.5.2.1 WBS
Generally, the Contractor shall be asked to de-segregate the Project into an itemised Work Breakdown Structure (WBS), which defines work packages together with the processes, activities and deliverables of each package. The WBS definition allows for the individual work packages to be planned, controlled and monitored independently while providing updated information compatible with both the overall work programme and other associated work packages. The standards on WBS are not elaborated on for I&C works, so the Owner / Contractor evolve their own WBS for I&C project activities.
2.5 Planning, Scheduling and Cost Control
Generally, three forms (see Figures 2.9 to 2.11) of WBS are intermixed in I&C, viz. AWBS, ZWBS, PWBS (Source: Yokogawa Electric Works, Japan (YEW)): a) Activity-based WBS (AWBS)
Figure 2.9 Work Breakdown Structure (AWBS).
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b) Zone-based WBS (ZWBS) e.g., Process Hazardous area, Geographical area such as Loading terminals, Tank farms, etc.
Figure 2.10 Work Breakdown Structure – ZWBS.
c) Product-based WBS (PWBS) e.g., Systems in Control room or Field
Figure 2.11 Work Breakdown Structure – PWBS.
2.5 Planning, Scheduling and Cost Control
2.5.2.2 CPD and CPM
CPD is an acronym of “Critical Path Diagram”; CPM is an acronym of “Critical Path Method”. The critical path “consists of the longest sequence of activities from project start to finish that must be completed to ensure the project is finished by a certain time. The activities on the critical path must be very closely managed. The critical path essentially determines the end date in your project schedule”. To identify a critical path, a software programme called Critical Path Method (CPM) is used (Figure 2.12). Initially, Milestones or Deliverables are identified. Then a Work Break Down structure WBS is first created which identifies the activities involved in a project. Then the activities are sequenced as tasks. Then the tasks are placed in a network diagram. Then each task is assigned a completion time set as Best, Worst and Most Likely (Figure 2.13). Then a weighted average is placed on Most Likely and an Estimate is derived as: E = Mean of (Best + X* Most Likely + worst), If X = 1, then E = (Best + Most Likely + Worst) / 3. The longest path through the network (not shown in figures here but usually depicted in “red” ) identifies the critical path. As work progresses and tasks are completed, the network is updated and the critical path changes as we move along. The determinations are done in a software package and the inputs come from progress reporting by Construction Work personnel. Using the critical path, more resources can be thrown on a task to achieve a shorter time to complete. However, the CPM does not adequately help in Planning unless it is combined with another approach called PERT, which helps in looking at various possibilities of running an activity (Figure 2.14). A PERT chart is drawn with circles for each activity, with the name of the activity and estimated duration in each circle. Arrows represent the paths that relate to dependencies. By this approach, Tasks 1 and 3 are the critical path. Activity time for some tasks may be unknown here but the sequence shows the critical path to be different from the CPM approach. But analysing separately a PERT or CPM for complex construction projects and comparing Progress vs. Planning is a difficult exercise, and to make planning easy-to-read, the PERT-CPM data is converted into a Gantt Chart, as shown in Figure 2.15.
T2
T6
T4
T5 T1
T7
T8
End
T7
T8
End
T3
Figure 2.12 CPM network.
T2
T6
T4
5
5
10 T5
T1 5 10
T3 20
Figure 2.13 CPM Task Weighted network.
5
5
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T15d
Start
T25d
T310d
End
T410d
Figure 2.14 PERT Chart.
Figure 2.15 Gantt chart.
Tasks on the critical path can have “Red” Gantt bars. PERT networks now allow red lines automatically in networks. However, PERT / Network plan, CPM and Gantt charts together are used by experienced Project Managers to plan, schedule and report. 2.5.2.3 Network Planning
a) Introduction Network is a tool used for planning, scheduling and monitoring the progress of activities so that Work and Time Management is under control and it is analogous of a PERT chart. All CPM and Gantt charts can also flow from a network plan (Figure 2.16). It is extensively used in Construction Management, where many activities, critical in nature and a large number of resources or activities are involved and therefore, will benefit by network-based organised planning. ●
●
●
The Network depicts: – project activities to be completed – the logical sequences and the interdependencies of activities – times for the activities to start and finish – the series of activities that will take the longest time to complete and decide project duration – provides a basis for forecasting the start and completion of various tasks. The network also helps to forecast the duration and completion time for the project construction. It also provides a basis for scheduling labour and equipment The network will serve to indicate when activities can be delayed and when they cannot
2.5 Planning, Scheduling and Cost Control ●
In short, the above forms the basis of various Construction Management software and is the core for development of further data engineering such as PERT, CPM and Gantt that were discussed earlier.
b) Terminology ●
●
●
●
●
●
Activity It is an element of the project that requires time. It may or may not require resources. Waiting for materials to arrive on site is an example of where time is consumed and no resource is required Merge Activity This is an activity that has more than one activity preceding it Parallel activities These are activities that can take place at the same time Path A sequence of connected, dependent activities Critical path The longest path(s) through the network. If any activity on that path is delayed then the entire project will be delayed by the same amount of time Burst activity This activity has more than one activity immediately following it.
c) Basic rules ● ● ● ● ● ● ●
Networks, typically flow from left to right An activity cannot begin until all preceding connected activities have been completed Arrows in networks indicate precedence and flow Each activity should have a unique identification number An activity identification number must be larger than that of any activity that preceded it Looping is not allowed Conditional statements are not allowed.
Activity Rule charts
An activity plan is now made as a table, e.g., for a business centre Network Information Country Business Centre Preceding Activity Activity Description Application approval None A B Construction plan A Traffic study A C Service availability check A D Staff Report B,C E Commission approval B,C,D F Wait for construction F G Occupancy H E,G
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d) Introduction to Network plan From the above, a network emerges as a flow diagram
A network computation process can now be introduced
The activity table now becomes:
The network plan now gets elaborated with Forward and Backward pass using simple rules, logics and math (e.g., ES + Dur = EF) • • • • • • •
Early start (ES) Early finish (EF) activity) Late start (LS) and Late finish (LF) activity and Expected time (TE), Critical path (CP) - longest path in the network which, when delayed, will delay the project Slack or Float - How long can the activity be delayed (SL)
2.5 Planning, Scheduling and Cost Control
A further exercise is made to determine Float or Slack that allows some activities to be delayed to save on optimising resources.
Figure 2.16 Network plan.
The above network plan shows the critical path in shaded box. Most project software allows the network work plan to be converted to charts, graphs and illustrations to assist Planning and Scheduling.
2.5.3 Introduction to Scheduling (and Use of S-Curve) Like project scheduling, construction scheduling is usually on multi-levels and usually at least up to three levels, and again WBS is used. 1) Level 1 (L1): Project summary: highlights the major project schedules, milestones and key deliverables 2) Level 2 (L2): Master Schedule: divided into Project Phases, L2 is the master schedule and indicates all major activities on a critical path. Any delay of the project is reflected in the L2 revised schedule, to determine the amount of delay in the project. L2 schedule is normally a part of the Contract or agreed and signed by all the stakeholders of the project just after signing the Contract and before the commencement of the work 3) Level 3 (L3): Detailed work Package Schedule. This schedule indicates the integrated Critical Path Method (CPM) overview of the project. Many Contractors follow this schedule for monitoring and controlling the project. The Contractor uses it for engineering, procurement, construction and commissioning purposes. This schedule also defines the overall critical path for the project 4) Level 4 (L4): Working schedule (Internal) where each schedule is expanded and followed. This also indicates the “work ahead” situation on a short-term basis in the project
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5) Level 5 (L5): A short-term (internal) schedule for a specific area having detailed activities to be coordinated on a dayto-day basis. The Contractor is totally responsible for the preparation and regular updating of detailed critical path networks, bar-chart schedules and accurately monitor progress, to ensure agreed project target dates are met. The Contractor’s scheduling correlates the activities; and for those purposes this Handbook also includes all the I&C discrete packages as well. The Contractor shall provide the scheduling and monitoring functions utilising the latest version of commercial off-theshelf, integrated Construction Management Software that use PERT-CPM-GANTT and other techniques. How to use an S-curve – an example:
Figure 2.17 S-Curve use.
As shown in Figure 2.17, plotting man hours (on the left vertical axis), and percent complete (on the right vertical axis) against time on the horizontal axis, both against a planned percent-complete curve (Brown dotted line) gives a method to evaluate project and cost status. It shows that after 6.5 months, the 13-month project is essentially around the 40% point. However, it also shows that the costs are exceeding the budget, and actually have been so since the work was initiated. If this had been allowed to continue without a change in course, it would have resulted in an 18% overrun (or greater) of the budget.
2.5.4 Introduction to Reporting (Gantt Chart) A. Reporting as a minimum shall include: 1) Daily summary, weekly and monthly progress reports including activities accomplished and milestones reached, overall progress “S” curves, tabulated planned vs. actual progress and manpower histograms 2) Analysis of work performed and its trend for the scope completion forecast 3) Recommendations to improve / recover performance with float details 4) Detailed monthly payment report including variation status in detail and projected payment plan 5) Detailed control of documentation status of each deliverable 6) Reporting on the Contractor’s staffing and site mobilisation plans 7) Cost estimation for variations 8) Cost allocation 9) Expediting Reports 10) Material consignment tracking System reports
2.5 Planning, Scheduling and Cost Control
11) Installation reports: ● a daily diary of events of a general nature recording weather conditions, installation activities completed and planned for the next day(s), delays, shutdowns, etc. ● daily manpower reports ● details of any delays ● dates when critical activities were started and completed ● field design change records 12) Punch Lists. 13) Site material control services shall include but not be limited to: ● issuing material receipt reports ● performing receipt inspection, checking for quality, damage and quantity of material ● supervision of field purchasing, issuing purchase requisitions for unforeseen items which could be supplied locally ● warehousing management ● reconciliation of all materials ● handling of surplus materials ● initiation of insurance claims ● settlement of claims, back-charges. B) S-curve, CPD, Histogram, etc. forms of the Report Generally, graphs and diagrams summarise a report faster than text and so figures speak a thousand words, especially in progress reports and their discussion in meetings. B1) S-curve and Banana curve S-curve or Sigmoid Curves (S-shaped) brings out the metrics of progress in a Construction Contract in a visual manner and some of the most common uses of S-curves are for progress and performance evaluation, cash flow forecasts, quantity output comparison, etc. ● ● ●
Project progress against the planned schedule Actual costs against budgeted costs Costs against progress as a measure productivity.
So, to create an S-curve, a Project Schedule and Time-line for activities must be prepared. With the plan as the base line curve and daily, weekly, etc. progress reporting of actual activity performed provide a comparison over time. Several formulae for Sigmoid equations are available to suit various requirements but in the Construction Industry the statistical cumulative distribution function that goes from 0 to 1 is used, as it accurately depicts the exponential nature of construction projects in the progress path. The Progress S-curve, Cash flow S-curve and Quantity output S-curve are shown in Figures 2.18 to 2.20. PROGRESS
100% 90% 80% 70% 60% 50%
Original Plan%
40%
Current Plan%
30%
Actual %
20% 10% 0% 9-Sep 0% 0% 0%
30-Sep 14-Oct 28-Oct 11-Nov 25-Nov 9-Dec 23-Dec 13-Jan 27-Jan 10-Feb 24-Feb 10-Mar 58% 67% 76% 84% 91% 5% 13% 21% 30% 39% 49% 97% 42% 54% 65% 74% 82% 90% 1% 5% 9% 16% 23% 30% 43% 50%
Figure 2.18 S-Curve – Progress.
31-Mar 14-Apr 28-Apr 100% 100% 100% 95% 98% 100%
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Figure 2.19 S-Curve – Cash. Note: Figure is representational and for format understanding only. Quantity Output S-Curve 250
200
Quantity
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150
100
50
Planned Quantity Actual Quantity
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Time
Figure 2.20 S-Curve – Quantity Output.
Two types of S-curves based on early and late scenarios of schedule overlap at the beginning and end of the project, producing a banana-shaped curve, known as “Banana Curves”. Floats or slacks in time are used for non-critical activities to plan late curves, while resources are diverted to complete critical activities (see Figure 2.21). The banana-shaped envelope of the early and late curves represents the range of possibilities that the project can expect if it is to be completed on time. B2) Histograms The histogram is a specialised bar graph that avoids the gaps in a conventional bar chart by an assumed mean value on numerical data between data collection times, i.e., instead of a line in a bar chart, numerical data is grouped in bins. It is used largely for manpower in the I&C construction industry (see Figure 2.22). The preferred software is Primavera (latest release) or MS Project (latest release). If Oracle or SAP is involved for a Database, the documents are integrated as a Life-Cycle Asset Management document. The software involved in Construction Management and their use are discussed briefly at the end of this chapter, where different Cyber-wares involved in Project Management are also briefly touched upon.
2.5 Planning, Scheduling and Cost Control S-curve with Early & Late Dates (Banana Curves) 25000 20000
Early Dates Late Dates
15000 10000 5000 0
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Figure 2.21 S-“Banana” Curve.
Figure 2.22 Histogram. Note: Figure is representational and for format understanding only.
Sep
Oct
Nov
Dec
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A sample Gantt chart for a Hydrocarbon project is shown in Figure 2.23: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
Refinery Project ABC FEED EPC Phase: Refinery Process Plant A Engineering Procurement (EP) Process Flow Diagram (PFD) PFD - HAZOP Review P&ID' s IFD (IFD - Issued for Design) Plot Plan (IFD) 30% (3D Model Review) Plot Plan IFC (IFC- Issued for Construction) Vendor Equipment data 60% (3D Model Review) P&ID's IFC 90% (3D Model Review) Piping ISO - IFC Contract Management Bidder Prequalification RFP package to Bidders (RFP- Request for Purchase) Commercial and Technical Evaluation of Bids Award Mobilisation Construction Civil works Equipment Erection Piping - Mecahnical works Electrical works Instrumentation works Mechanical Completion Pre-commissioning Commissioning Handover - Plant Guarantee run
Figure 2.23 Typical Project Gantt chart (PRIMAVERA).
A Critical Path Diagram (CPD) sample for a project is shown in Figure 2.24.
Figure 2.24 Typical Critical Path Diagram (Primavera).
2.5 Planning, Scheduling and Cost Control
By placing a scale across the diagram, all critical activities that must occur sequentially or concurrently become obvious.
2.5.5 Introduction to Construction Cost Estimation A process plant must be visually understood before any costing can be applied as a plot, as shown in Figure 2.25. 2.5.5.1 Overview
Refinery Project costing is a very involved exercise that requires a software to produce and manage. Essentially the math involved is regression process using the parametric approach. As stated earlier, it involves: A) Types of contracts A1. Single or Prime Contractor: here, monitoring and supervision is by Owner A2. PMC or Project Management concept: Independent Group management with several prime Speciality Contractors A3. Prime Speciality Contractor for each area of work, with either Project Management Consultant team hired or Owner’s dedicated construction department supervising works A4. In-house construction team that has some in-house crews and speciality contractors for each discipline or area of work. Project size, complexity, feedstock details such as Crude or Naphtha and even product value (anticipated band over the life of plant), etc. have a bearing on contracts. Nowadays, for Refinery projects that are grass-root with many units or large brown-root expansions, more than half are Type A3 or a more complex approach of several permutations and combinations of above. However, any work such as Upgrade of Instrumentation or Automation in a running plant or nearby is usually Type A4. B) Costing basics In its simplest form: Plant Investment cost = Direct costs + Indirect costs + Start-up Costs Start-up costs period is between Mechanical Completion and Production at 80 or 100% throughput for 48 hours. As per many estimates, most start-up costs estimate with a plan such as Direct: 50–60%; Construction: 20 –25%, Engineering: 10% and the rest: 7 to 10%. Many studies have identified the following Direct and Indirect Expenditure list for a Refinery project as shown in Table 2.1 below:
Figure 2.25 Cost Estimation Plot.
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Table 2.1 Direct – Indirect – Start-up cost division. No.
Direct Costs
No.
Indirect Costs
No.
Start-up costs
1
Lump sum Equipment Cost - Columns, Heat Exchangers, Pumps & Compressors, Tanks, Package plants etc.
A
Process Design & Spec costs
I
Plant operational startup manpower & resources
2
Direct Material - (Others) cost
B1
FEED cost
II
Line Flushing, Inerting, Steam Traps & Drain / Vent checks, Safety valve seal Checks, Blinds's check etc.
2.1
Instrument
B2
Detailed Engineering cost
III
Initial Inventory of spares, Catalysts & Chemicals, Fuels, Oil, etc.
2.2
Electrical
C
Project management Services
IV
Loop Tuning, etc.
2.3
Insulation
D
R & D works
V
Finishing works of Civil, Touch painting, Site Restoration etc.
2.4
Heat & Mass Transfer - fired Heaters etc.
E
Management softwares for construction
VI
Capex Contingency for minor De-bottlenecking
2.5
Civil works - Structures, Piling, foundation etc.
F
Legal expenses
2.6
Painting
G
Prime Contractor or Specialist contractor's Field labour cost
2.7
Road & access works - multi-discplinary
2.8
Mechanical ETC.
4
Direct Construction labour _Equipment Installation
H
Project Financing Costs
5
Piping - Materials
I
Contingency
6
Piping - Installation
7
Service - Steam, water, fuel, Air, Waste Treatment, HSE including Fire Services
8
Speciality Sub-contracts - material & labour
9
Property (land) & its taxes
10
Shipping, Freight & Plant Insurance
11
Unplanned capex during & after start-up for Debottlenecking
12
Site Preparation - Temporary fixtures & facilities at Site
13
Contingency
The costs are then split into project phases as follows: 1) Conceptual Planning (after Feasibility Study) 2) Process design or FEED 3) Detailed Engineering design or DE 4) Site Preparation (if very extensive infrastructure is planned such as shipping docks, rail loading, etc.) 5) Construction 6) Start-up.
2.5 Planning, Scheduling and Cost Control
Every phase is further split into associable parameters, usually on a WBS system. C) Cost preferences Also, pricing can be: C1) Firm Fixed price C2) Cost Plus – usually with Incentive fee C3) Time- and Materials-based. D) Cost Estimate classes Universally, the cost estimate is divided into a five-class structure or phases in ascending or descending order with respect to Project Start to Final or Project Knowledge development. Some compress the exercise to three / six levels by combining or segregating phases. The Input availability is mentioned in brief in definitions below. However, a table is provided sourced from a recommended practice of an AACE–18R7 article and details must be referred to there. Note: AACE International Recommended Practice No. 18R-97 – Cost Estimate Classification System – As Applied in Engineering, Procurement and Construction for the Process Industries TCM Framework: 7.3 – Cost Estimating and Budgeting D1) Class 5/1:Rough Order of Magnitude or ROM Estimate i) Phase of project: usually done during the Feasibility Study and / or Conceptual Planning ii) Accuracy expected: over 30% iii) Inputs Availability: 15% of Project definition of Feed and Products and so operational units, PFD, Major Equipment Lists, Identified major Construction activities iv) Purpose: a) Feasibility Estimate b) Initial ROI estimate for determining cone of costs v) Degree of effort: 1 (by man hours – MH). D2) Class 4/2:Authorisation Estimate i) Phase of project: Budget Estimate ii) Accuracy expected: ±30% iii) Inputs availability: Block diagram, Plot plan, P&IDs and UIDs at 40–60% completion iv) Purpose: Management or Board approval for Project Go-ahead v) Degree of effort: 4 (MH). D3) Class 3/3:Tender / Bids Estimate i) Phase of project: Process design or FEED stage ii) Accuracy expected: ±20% iii) Inputs availability: 70% on Equipment and 30% on Construction works a) Unit Direct material cost of items within the range of accuracy expected must be available at this stage to the extent of at least 70% b) WBS, Network plan with Project Start and Final dates, equipment and manpower scheduling, progress charts and material take-off (MTO) must be available as initial information. iii) Purpose: Control Estimate for Tenders iv) Degree of effort: 10 (MH). D4) Class 2/4:Definitive Estimate i) Phase of project: After or during Detailed Engineering ii) Accuracy expected: ±10% iii) Inputs Availability: Direct Equipment costs, Unit cost with (forced) MTO iv) Purpose: Control Estimate for Construction v) Degree of effort: 20 (MH). D5) Class 1/5:Detailed Estimate i) Phase of project: 85–90% Mechanical completion ii) Accuracy expected: 5% iii) Inputs Availability: 85–90% of Project, Detailed MTO
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iv) Purpose: a) To settle Subcontractor / Contractor claims b) Revised ROI Return of Investment (ROI) estimate c) In-house base line for future estimates. v) Degree of effort: 5 to 100 (MH) or 0.5% of project cost (100 = 0.5% of project cost). E) Detailed Input availability for Cost classes The chart shown in Figure 2.26 provides an indicative reference overview of type of Input availability required for classes. F) Cost Estimate methods Cost estimation methods vary for different phases of the project and combine different techniques until the project clarity reaches 60% on previous data and base line estimations with extrapolation to present date. Then the Unit costs approach is taken or Relative cost factor or some other factor is taken based on Regression Analysis. Note: Simply stated, what weighs most in various types of costs is a stochastic estimation based on Regression math and a factor is derived as a multiplier based on weighted averages of various parameters that influence costs, often known as the parametric method.
Figure 2.26 Class and Input availability matrix.
2.5 Planning, Scheduling and Cost Control
a) Method of Estimation b) Base line cost estimation methods such as: i) Marshal and Swift Process Industry Index (base = 100 in 1926) – For Equipment ii) Nelson Farrar Refinery Construction Index (base = 100 in 1946) – For Construction iii) Chemical Engineering Plant Cost Index (base = 100 in 1957–59) – For EPC iv) Lang factors – used for ROM exercise only – an equipment such as distillation column is taken as representative of all columns and a Lang factor is used for all similar equipment v) Base capacity factor = (Proposed capacity / Base capacity) ^CF coefficient. Capacity Factor Co-efficient is an exponential factor. c) Detailed Item estimation methods such as: i) Using a Specialist Service to estimate using parametric model and regression analysis ii) Data sources updated every year, e.g., Richardson Rapid Estimating Systems iii) Unit with Corrected Index using the following or equal formula: Prices from quotations or index-corrected records. C = [Σ( E + E L ) + Σ( f x M x + f y M L ) + Σfe H e + Σfddn ] fF See p. 250 in Peters et al., 2003). (10–20% accuracy, definitive or preliminary estimate) E: delivered equip. cost EL: labor for equipment cost for field labor fx: material unit cost fe: unit cost for engineering fd: drawing cost fF: field expense factor Source article: From Chemical engineering article ChE 4253 - Design I d) Indirect costs as percentage of direct costs or items in the direct and indirect cost are evaluated as a percentage of the delivered-equipment cost I = E [A (I + FL + Fp + Fy)] + B + C Where: I = Battery Limits Investment = Indirect cost factor representing contractors’ overhead/profit, engineering supervision and E contingencies A = Estimated total cost of all battery limits equipment (carbon steel) on Free on Board FOB basis Cost factor for field labour FL = Fp = Cost factor for piping materials Fy = Cost factor for miscellaneous items B = Erection cost of all equipment estimated (Furnaces, tanks etc) C = Incremental cost of alloy materials used for corrosion resistant properties.
e) An article giving another form of cost estimation is illustrated below: (Source article: Dr Uchema O Ajator – IOSR_JESFT-2014) f) Approved Vendor Limited Tender Exercise The lowest three tenders on notional Quantity with discounts on volume increase is selected for the future – vendors are provided with a fee to quote. G) Cost Reporting Generally, the minimum reporting required are: ● ● ● ● ●
Cost performance Index (CPI) Schedule Performance Index (SPI) Percent Complete (based on Investment forecast cost) Quantified Schedule variance (in cost from Completed – Budgeted Schedule) Progress Schedule variance (Cost spent – Cost planned to be spent).
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2.6 Technical Spec Tender and Template An Index, Company Cover letter, Notice inviting Tender, Criteria for pre-qualification, etc. are not part of the template in this Handbook, as every Company has its own template for Tender Issue content. A typical content Index is shown below: Volume I – Commercial Section of the tender Section A – Notice Inviting tender (NIT) Section B – Instructions to Bidders (ITB) Section C – General Conditions of the Contract (GCC) Section D – Special Conditions of the Contract (SCC) Section E – Schedule of Rates Section F – Annexures to SCC F1 – Schedule of time F2 – Terms of payment F3 – Materials to be provided by Contractor & free issue materials F4 – Manpower deployment schedule by contractor F5 – Tools & tackles, equipment including calibration equipment to be deployed for the project F6 – Equipment deployment schedule F7 – Contractor’s Quality Assurance Plan & policy F8 – List of similar jobs executed F9 – Current jobs in progress with percentage completion of each job F9 – List of Owner approved vendors / suppliers F10 – Safety procedure, permits F11 – Bank Guarantee proformas
Volume II – Technical Section of the tender Section AA – Project description AA1 – Project Description AA2 – Project Scope of work Section BB – Project Schedule Section CC – I & C Contractor scope of work (Instrumentation) CC1 – Installation woks CC2 – Testing & calibration works CC3 – List of drawings to be provided by owner CC4 – Drawings to be provided by Contractor CC5 – Materials to be supplied by contractor and the procedure Section DD – Quality procedure DD1 – Quality Assurance - Installation DD2 – Quality control - Installation DD3 – Method statements, ITP DD4 – Quality Assurance - Material Procurement DD5 – Quality Control - Material Procurement
This Handbook has addressed content under various sections to fill in or get guidance to most Indexed Technical headers. Given below (in italics) is a Typical Tender techno-commercial specification for I&C Construction and is to be seen as a template only. Note: Not intended to be according to the content Index sample above; also, likely to be issued by a Company and written from the perspective of that Company (unlike the rest of the Handbook, generally written from a Contractor’s perspective), hence in italics. The actual requirements vary from project to project. The Handbook provides the details necessary to formally issue TechnoCommercial parts of the Tender. It must be again emphasised that it is written from the perspective of the Company and not Contractor, unlike the rest of the Handbook, to safeguard the Company’s interests in the Tender.
2.6.1 Introduction The scope of works and responsibilities specified herein includes all associated works necessary for a Lump sum turn-key construction design and site engineering, calibration, installation / erection, testing, documentation, pre-commissioning and commissioning assistance of all necessary works of all instrumentation related works of the Company. The term “Owner” refers to the Company. The term “I&C Contractor” and “Contractor” referred to in various sections shall refer to the Organisation quoting against this Tender. The term “Engineer-in-Charge” refers to the designed Senior Engineer / Manager who would be stationed on site for the duration of the project on behalf of the Company. First, the instrumentation and automation that is being described in the ensuing pages is for a plant. Second, bidders must compulsorily visit the plant site for plant familiarisation prior to tender submission, for qualification and award. The I&C Contractor shall be completely responsible for erection, installation, calibration, cabling and wiring, supply of erection hardware defined elsewhere in the specification and consumables, testing, pre-commissioning and providing commissioning assistance of all instrumentation related works. This includes provision of supports for instrument related items and minor civil works such as chipping the floor for laying conduits, grouting, remake, making necessary cut-outs in the floor or in the wall for cable entries and making concrete pedestals for instruments and local panels. This also includes co-ordination with other discipline Contractors for effective completion of instrument works, wherever necessary.
2.6 Technical Spec Tender and Template
Painting of all structural steel supplied by the Contractor and final coat and / or touch-up of structural members provided by the Client wherein instrument related supports have been welded and repair of galvanisation of items used for instruments is included in the scope of the I&C Contractor. The works shall not only conform to drawings and documents referred to in this specification but shall include any other document provided by the Engineer-in-Charge on site. Best trade practices for good workmanship and high safety shall govern all works. The Contractor shall follow the safety rules prevailing the plant and shall follow all the safety procedures formulated by the Client’s safety officers. All the necessary procedural coordination that is required to get the work permits shall be undertaken by the Contractor. All materials and workmanship shall conform to the latest edition of applicable national and international codes and standards and statutory regulations, as applicable. Local BSI, IEC, etc. standards shall apply, in general. Note: ● ●
For the List of Reference Engineering Documents issued with the Tender, please see Annex 1 (Section CC3 as per Table of Index) For the technical specification for performing the contract, please see Annex 2. (Volume II as per Table of Index) For the Technical specification for supply of major construction materials, please see Annex 3. (Section CC5 as per Table of Index)
●
For the Bill of Quantities and Tender Schedule, please see Annex 4. (Sections E and F1 as per Table of Index).
(Annexes may be filled-in based on this Handbook’s details relevant to project). Where a conflict between the various documents is perceived, the same shall be resolved with the Engineer-in-Charge before proceeding with works. The decision of the Engineer-in-Charge is final in such matters.
2.6.2 Scope of Works and Supply General scope in I&C Contractor’s scope of supply, works and responsibility shall also include but not be limited to the following, complete with supply of all test instruments / tools / tackles / fasteners / consumables for all works: a) Unloading of all instrument and instrument items and including consoles, panels / cabinets at the warehouse / field and transportation from warehouse to the locations as required by the job requirement b) Moving, installation, mounting, aligning and bolting of consoles, cabinets, panels and boxes in the Control room and the field, including fabrication and supply of base frames, if required c) Assistance / supervision in mounting on-off valves / control valves and accessories d) Installation / mounting of all instruments complete with all manifolds including the supply of manifolds where specified and accessories e) Mounting of in-line instruments including fee issue items and accessories including supply and erection of spool pieces, if found necessary f) Provision of nameplates or rain canopies or weather protection covers g) Minor civil works such as chipping of paved areas / floors for laying the conduits and refilling the chipped areas h) Minor civil works like chipping and grouting of instrument local panels / supports / stanchions and refilling i) Sealing / insulating of unused tubes / pipes / cable conductors as required j) Plugging the unused entries in the junction boxes using weather proof / exproof plugs if required k) Contract final measurements l) Cleaning of the work area and removing of the post erection debris and disposing the same as per the instructions of the Engineer-in-Charge m) Provision of necessary scaffolding and access ladders for carrying out the work specified. 2.6.2.1 Calibration Works
Calibration / functional testing of the various types of Instruments and control valves detailed elsewhere in this tender as per manufacturer’s instructions with their accessories is in the Contractor’s scope. Supply of all test and measuring instruments, calibration and testing is also in the Contractor’s scope. The Contractor shall mobilise suitable trained and experienced personnel for calibration and establish test facilities on award of Contract on site.
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The instruments (Secondary standards) brought to site shall have a valid test certificate issued from a recognised testing Lab. All the instruments can be taken back after completion of project. The calibration records shall be submitted in approved format after compilation. Format to be submitted for the approval of Engineer-in-Charge. 2.6.2.2 Supply and Installation Works
n) Supply and fabrication and erection of supports for instruments and instrument items like junction / termination boxes, etc. o) Fabrication and supply of condensate pot with relevant test certificates as per standards p) Mechanical Installation of Instruments and instrument items with their accessories, including supply of 2- diameter pipes (stanchions) q) Supply of ducts, trays, ladders and their associated bends, elbows and tees for cable laying as per specification, installation of supports without mechanical strain r) Erection of main and branch overhead trays complete with bends, tees, fabrication and erection supports and provision of openings where required, including provision of covers where required, maintaining earthing continuity, etc. s) Supply with fabrication and erection of supports for cable ducts, trays, ladders and associated accessories, etc. 2.6.2.3 Cabling, Laying and Wiring Works
t) Lay, dressing, termination of all cables in trays, ladders and trenches, complete with cable tag and ferrule identifications u) Wiring / Cabling, electrical interconnections, etc. including laying and dressing in trays / angle iron, with termination at both ends (clamping, glanding and ferruling included) and dressing, from field to Control room / MCC room of power, signal and earthing cables for instrument items and their accessories v) Supply of cable glands and cable lugs are in Contractor’s scope w) Cable-tag and ferrule identifications are included in the I&C Contractor‘s scope x) Testing of cables (continuity and megger) prior to installation shall be carried out y) Excavation, sand filling, brick laying and back filling for the purpose of laying instrument cables near Control room if necessary z) Sealing of entries to Control room / closed rooms after laying of cables. 2.6.2.4 Piping and Tubing Hook-Up Works
aa) Supply, installation and support of Impulse hook-up, Pneumatic hook-ups, Air sub-headers, capillary tube support, if any, etc. bb) Supply and installation of Primary Impulse tubing / piping. Supply and installation of valve-manifolds and fabrication / erection of supports with their accessories cc) Supply and installation of Air Supply Tubing / piping, fittings and valves and installation complete with fabrication and erection of all supports for instruments and instrument items with their accessories dd) Fabrication of pipefitting such as nipples and their threading with socket welds and seal welds as required. Cold bend of (Hot bend is not allowed) for tubes or pipes ee) Sealing of threaded joints by Teflon-tapes / high temperature seal is included. 2.6.2.5 Earthing Works
a) Preparation of Earth pits outside the Control room b) Earthing of steel Stanchions, Junction Boxes and Trays / ladders, etc. c) Checking of earth resistance loops and adding additional star connected earth pits to meet required resistance to ground is also included in the works. Records of measurement shall be submitted. 2.6.2.6 Loop Check Works
a) Loop Check of all types of analogues, digital (contact), mechanical and electro-mechanical functioning of all instrument and instrument items (including package equipment) under witness of Engineer-in-Charge or their assigned representatives
2.6 Technical Spec Tender and Template
b) Loop check shall include the DCS control and control valve action along with the end-to-end complete simulation of the start-up and shutdown scheme, excluding the drive motors c) Loop check records shall be submitted in the Company approved format after compilation. 2.6.2.7 Documentation
Preparation and submission of As-built mark-ups on documents / drawings of detailed construction engineering / changes on site shall be done with clarity and support sketches, if required. 2.6.2.8 Pre-Commissioning and Commissioning
Pre-commissioning and commissioning activities shall include: a) b) c) d) e) f) g)
Flushing, Hydraulic testing, Leak testing and Air drying of Instrument impulse lines Flushing, Hydraulic testing, Leak testing and air drying of Instrument air lines Trimming of all Instrument calibration, local settings, trip point settings shall be carried out Re-calibration of any vital Instrument if requested may have to be carried out Temporary disconnection and reconnection of tubing / wiring may be required Degreasing / lubrication of moving parts and accessories may be required Pre-commissioning is part of the I&C Contractor’s scope and it shall be before plant start-up.
An engineer, two instrument technicians and an electrician shall be assigned for assisting during the commissioning on a per-diem basis for the commissioning phase, i.e., during and after plant start-up until take-over by the Client. 2.6.2.9 Information From Tenderer
The following information shall be provided by the tenderer along with their quotation: a) Pricing shall be in a lump sum for works along with unit prices for works and supply for additional works, as per attached schedule b) Unit rates for addition and deletion of works and supply shall be included in tender pricing. This rate shall be negotiated further on a quantity basis in the event of addition, adding to price variation of greater than or equal to 0.5% of tender contract c) All indirect costs, if any, shall be shown separately d) Prices shall be firm for work scope change of the order of ±20%. Prices shall be firm for supply scope change of the order of ±10%. Increases beyond the above shall be governed by unit rates e) The I&C Contractor shall submit a draft schedule for implementation and completion, including time required for mobilisation along with manpower deployment schedule and delivery schedule of supply materials. The Contractor shall also provide an organisational chart including brief resumes of the key personnel who are proposed to be deployed for this project. This shall be submitted along with the erection quote f) List of equipment including calibration equipment (hydraulic test pump, compressors, generator-sets, welding equipment, etc.) along with instruments, tools, tackles and accessories; and any other implement considered necessary for completion of works to be submitted. (The decision of the Engineer-in-Charge shall be final in this regard, after their review and approval at the time of mobilization.) g) A micro-level plan for implementation of day-to-day works shall be provided in consultation with the Engineer-in-Charge. This shall be suitable for progress measurement and for construction-schedule recovery management in an MS project, along with a mobilisation plan. The preliminary plan shall be submitted by the I&C Contractor within one week after award of contract h) The Contractor within one week of award Contract shall also submit the billing basis and billing schedule for the Contract in question and the same shall be discussed and mutually agreed upon prior to the mobilisation i) Income tax and Sales Tax Clearance Certificate j) Company profile, list of similar jobs done, solvency certificate with balance sheet and audited financial statements for the last two years k) Power-of-Attorney in the name of the person who has signed the tender documents. 2.6.2.10 Mobilisation and SITE Management
The number and type of workers / personnel mobilised / deployed shall be approved by the Company throughout the course of execution of the project. The Company reserves the right to demand either an increase in workforce or change in composition
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of the workforce, if the Engineer-in-Charge deems that the Contractor is not achieving the progress as per project schedule. The same shall be implemented by the Contractor without any contractual and financial implications. a) Stores shall be maintained by the Contractor who shall prepare the necessary requisitions and withdrawal slips for FreeIssue items. The register format shall preferably in a PC-based accounting system b) The following critical dates shall be strictly adhered to: ● Date of Mobilisation ● Date of Completion. c) Space for the site office shall be provided in consultation with the Client. The Contractor shall indicate required space d) The temporary structures required for the site office / calibration room (air conditioned) and the temporary storage facility prior to installation for free issue items which are being calibrated and stores for contractor supplied items shall be built by the Contractor. The same shall be demolished within one week or reasonable agreed time period of handing over the plant / system e) Alternatively, the Contractor shall bring in a Portacabin with all fittings. An air-conditioned room shall be provided for the Engineer-in-Charge free of cost f) The Contractor shall indicate in their quotation the costs that are considered by them towards the above two options g) Power and water consumed and other facilities, if any, shall be charged as actuals h) Fax-Phone / Photocopying facilities, if present on site, shall be made available as actuals + 10% handling charges to the Contractor. Alternately, the Contractor may make their own arrangements i) All Safety and Security related rules and regulations in force from time to time should be strictly adhered to by the Contractor and their employees j) Affiliations of all personnel working for the Contractor shall be easily identifiable by a uniform / helmet or some such means. 2.6.2.11 Labour Laws and Law Requirements
a) The Contractor shall make use of the local labour available and wages shall be paid as per rates prevalent at the time. All labourers shall be provided with the facilities which confirm to the provisions of labour laws as per the Contract Labour Act applicable for the region b) It is mandatory on the part of the Contractor to cover the Employees under the Worker’s Compensation Act (and / or such similar local or government acts) and shall pay and bear the expenses thereof and shall comply with all statutory provisions under labour law as may be appropriate c) The Contractor shall at all times indemnify the Company against any claim which may be made under the Workmen’s Compensation Act or any statutory modifications thereof, any damage or compensation payable in consequence of any accident or injury sustained by any employee or other person whether in employment or whether employed by the Contractor or not. If the Company is required to defend any claim brought under the Workmen’s Compensation Act, or any statute, the Contractor shall, at the request of Company, deposit with the Company a sum sufficient to cover any liability or expenses which the Company might incur by reason of defending any such claim. d) The Contractor shall at all times indemnify the Company against any monetary claim or payment by the Company to any person or statutory authorities under the Employees Provident Fund, Family Pension Fund or Employees State Insurance Act or any other Enactment e) The Contractor shall also indemnify the Company against all liabilities whatsoever under such other acts or statutes or Rules and Regulations of competent authorities as may be applicable to labour, or men employed by the Contractor or compensation in respect of any claims arising out of or in the course of the work contemplated under this agreement and against all costs, charges and expenses incurred or suffered by the Company in or about the matter arising statutorily or otherwise f) The Contractor shall also inform the Company in writing of the details of the employees / labourers engaged by them for carrying out the work under this agreement. It is the responsibility of the Contractor to see that the persons employed by them inside the premises of the Company, observe discipline and decorum to the satisfaction of the Company’s supervisory staff, and shall be subject to rules and regulations of the Company as to safety and security as in force from time to time g) The Contractor shall make use of the local labour available and wages shall be paid as per rates prevalent at the time. All labourers shall be provided with the facilities which confirm to the provisions of labour laws as per the Contract Labour Act applicable for the region h) The Contractor should ensure that they engage no person below the age of 18 years for carrying out the work under this agreement
2.6 Technical Spec Tender and Template
The Company will not and cannot be held responsible and liable for any injury or death that may be caused either to the Contractor’s workmen / representative, resulting from accidents or any other cause in carrying out the obligations under this Agreement. The Contractor shall not sub-contract any portion of the Contract or employ a labour Contractor without obtaining the prior permission of the Engineer-in-Charge. The Engineer-in-Charge reserves the right to approve or reject any such arrangement and the decision of the Engineer-in-Charge shall be final in this regard. The Contractor shall not make the Company liable to reimburse the Contractor to the statutory increase in the wage rates of the Contract labour appointed by the Contractor. Such statutory or any other increase in the wage rates of the Contract labour shall be borne by the Contractor. 2.6.2.12 Insurance
a) Workmen compensation insurance for their and their Subcontractors’ staff and labour are to be provided and maintained by the Contractor b) The Contractor will also cover insurance, i.e., Marine cum Storage cum Erection / Construction, etc. and then all risk covers up to payment of last lease rental by the Company, in respect of those equipment, which are in their scope c) Employer’s Liability Insurance, Public Liability Insurance, Transit Insurance (if any) shall be taken by the Contractor and any deductibles set forth in any insurance shall be borne by the Contractor. The details of the policies covering the risks mentioned along with certificates, etc., shall be furnished to the Company by the Contractor prior to commencement of works If any of the policies expire or are cancelled during the Contract term or the Contractor fails to renew for any reason, the Company will renew or replace the same at the cost of the Contractor and deduct from the receivables. 2.6.2.13 Contract Unassignable
The Contractor shall not, without the Company’s prior written consent, directly or indirectly assign, transfer or sub-contract the work contemplated under this Agreement. 2.6.2.14 Contractor’s Warranty
a) The Contractor warrants that all goods supplied and works done under this Contract are fit and sufficient for the purpose for which they are intended to be used; that they are merchantable quality and free from defects, whether patent or latent, in both material and workmanship. The benefit of the warranty together with any other warranty given by the Contractor or on their behalf or as may be implied by law shall pass to the Company, its successors and assignees b) The Company will not and cannot be held responsible and liable for any injury or death that may be caused, either to the Contractor’s workmen / representative resulting from accidents or any other cause in carrying out the obligations under this Agreement c) The Contractor must warrant that their performance of work shall be of high quality and in conformity with all required and specified specifications, drawings, standards set forth in the Contract and instructions provided to them by the Company from time to time during execution of the Contract. If the Company notices that any work carried out by the Contractor is not in accordance with terms and conditions of the Contract, during execution of the works or within the Performance Liability Period, the Contractor upon receipt of the notice, shall undertake to perform all corrective work required to meet the specifications, confirm to the Warranty, at the Contractor’s own expenses. If the Contractor fails to perform the corrective action within a reasonable time, the Company, in its option, shall carry out the remedial works through other agencies and charge the Contractor from the dues or from the performance security deposit / guarantee. 2.6.2.15 Contractor’s Guarantee
The Contractor guarantees that the equipment / goods used in the project are without infringing any patent, registered design or similar monopoly rights, and the Contractor will hold the Company indemnified from and against any damages, compensation, costs and expenses resulting from any such infringement or alleged infringement, whether paid or incurred in consequence of an order of Court or by way of voluntary settlement of a claim which the Company is advised not to contest. The Contractor shall obtain required guarantees / warranties from the equipment / material suppliers / vendors and their Subcontractors including Erection Contractors against defects in supplied items and workmanship.
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2.6.2.16 Inspection and Tests
a) The Company shall be entitled to inspect the quality of the material used and the parts of the equipment as per approved detailed Quality Control Inspection Test Plan during fabrication at vendor works and during commission and installation of the equipment b) The Contractor shall carry out the test run at the site as contemplated in this agreement and to the entire satisfaction of the Company in order to achieve the guaranteed performance given by the Contractor. 2.6.2.17 Confidentiality
All information / data supplied by Company or derived therefrom are strictly confidential and shall not in any way either directly or indirectly be used by the Contractor for its own benefit or any third party. The Contractor shall not, without written consent of the Company, use any document or information except for the purpose of performing the works. All documents provided to the Contractor shall remain the property of the Company and shall be returned on completion of works. 2.6.2.18 Contractor’s General Indemnity
The Company shall not be held responsible or liable for any loss, damage or expenses to the Contractor resulting from the Contractor’s execution of this agreement with the Company. The Contractor further agrees to protect, defend, indemnify and hold the Company harmless from and against all claims, suits, liabilities, etc., which may arise in favour of the Contractor or its agents, etc. on account of any injury or death or damage to property as a result of performance of works or negligence or otherwise in whole or in part or any other fault. 2.6.2.19 Arbitration
In the event of any question or dispute arising out of this Agreement, the same shall be referred to arbitration in accordance with the provisions of Arbitration and Conciliation Act 1996 or any statutory modifications or re-enactment thereof and the venue of such arbitration shall be at plant jurisdiction. 2.6.2.20 Jurisdiction of Courts
The Courts (that have jurisdiction of the plant or place of head office of the Company) shall have exclusive jurisdiction over the terms and conditions of this tender. The Contractor shall ensure full compliance of various (Indian) Laws and Statutory Regulations, to the extent applicable, as stated in the Tender, but not limited to, in force from time to time and obtain necessary permits / licences, etc. from appropriate authorities for conducting operations under the Contract. 2.6.2.21 Force Majeure
In the event of any failure in the performance of this agreement due to any force majeure such as war, civil commotion, riots, insurgency, strike, accident, labour, dispute, fire, natural disaster or governmental law, bye law and any notification, rule, regulation, act of God or order of any court or other judicial body or any other cause whatsoever beyond the control of a party to this Agreement, the party so failing shall to that extent, be exempted during the period of such happening from the liabilities that would otherwise result from its failure. The same shall be notified to the other party within 48 to 72 hours of the alleged beginning. Both parties have the right to terminate the contract, with prior written notice, if the situation continues beyond 15 days with no solution visible / forthcoming. 2.6.2.22 Annexure 1 to Section 2.6
(Section CC3, Section DD, Section AA2 as per table of Index) Documents Issued With Tender List of Reference Engineering Documents (Typical Tabulation)
2.6 Technical Spec Tender and Template
ANNEXURE 2 (Section AA, Section BB, CC1, CC2 as per Table of Index) i) General Technical Specification for I&C Supply and Works ii) Intent of Specification This specification details the broad guidelines for installation, testing and commissioning of instrumentation and control equipment and panels (I&C). This specification also outlines technical requirements and essential particulars for fabrication and supply of erection materials. However, the work shall, at all times be carried out strictly as per the instructions of the equipment manufacturer. The exact scope of work shall be as indicated elsewhere of this specification. iii) Codes and Standards iv) Guideline for Instrumentation and Control, System Installation 2.6.2.23 Annexure 3 to Section 2.6
(Section CCS as per Table of Index) The Bulk Construction Material Specification is detailed in Chapter 4, so that it may be used as a Pull-out form. It is suggested to the Chrono-reader of this Handbook, to jump to Chapter 4 and familiarise themselves with typical specifications, even if some or all are not in the Contractor’s scope of supply, so that discrepancies in the Company specification may stand out in the Quality Control review. 2.6.2.24 Annexure 4 Tender Schedule of Rates Format
(Section E as per Table of Index) Sample work description
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Note: Figure is representational and for format understanding only.
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3 Site Operations Manual – I&C 3.1 General 3.1.1 Engineering Handover A) Generally, the following Contract-related documents (see Table 3.1), as a minimum of a non-commercial nature or quasi-commercial nature, should be available at the time of Site Mobilisation for successful Construction Management. Table 3.1 Contract Documents List.
B) Typically, the following Engineering Drawings and Documents (as shown in Table 3.2), as applicable, should be available with overall 80 to 85% completion at the time of Site Mobilisation for successful Construction Management.
Handbook of Construction Management for Instrumentation and Controls, First Edition. K. Srinivasan, T.V. Vasudevan, S. Kannan, and D. Ramesh Kumar. © 2024 John Wiley & Sons Ltd. Published 2024 by John Wiley & Sons Ltd.
Table 3.2 Engineering Drawings and Document List.
3.1 General
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3.1 General
3.1.2 Site Structure for I&C Works Contract The site organisation structure used in a medium-sized crude Oil Refinery of 1.0 to 3.0 MMTPA is given in Figure 3.1.
Figure 3.1 Site organisation structure for a medium-sized Refinery.
3.1.3 Introduction to “Smart Instrumentation” Software The fill-in information is already embedded from a common database such as Oracle software or SAP, or if the Owner plans or uses a Life-cycle Instrumentation engineering tool software such as Intergraph’s “Smart Instrumentation”, previously known as “Smart Plant Instrumentation / SPI InTools / InTools”. A typical embedded database-based Data sheet and a Loop drawing in InTools software are shown in Figures 3.2 and 3.3, with links to the database as references in each fill-in. SPI / similar software allows: a) Defining units for measurement b) Creating Instrument and control loops by creating and defining Loop profiles that are typical or even one-off in the plant
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Figure 3.2 Typical SPI “embedded data” Data sheet (Intergraph).
3.1 General
Figure 3.3 Typical SPI “embedded data” Loop sheet (Intergraph).
c) Defining process data d) Performing calculations and sizing e) Managing specification documents f) Creating wiring details g) Creating reference tables h) Generating Hook-ups of all types i) Creating Loop diagrams, etc. Many software allow generating calibration table format and other records format for embedding the database, such as Smart Plant Instrumentation (SPI). Many DCS manufacturers now offer “adapters” to interface such database software to DCS. Furthermore, calibration assistance software is now available as part of a software suite of Asset Management systems (e.g., Intelligent Device Manager – Emerson).
3.1.4 Preliminaries and Sequence of Works – I&C The Preliminaries before Site I&C works begin include: a) Engineering Survey b) Data Validation Review c) Method Statement Review – for major activities. A Method Statement Review along with the Review of Drawings issued for Construction in the Pre-installation phase is for constructability checks. Incompleteness of the Drawing or Methods list, as part of the Engineering Survey and Data Validation Review, will show up as a Material Availability issue. Many Method Statements prepared as a separate contract document for I&C, as described below, also include or repeat the General Site Operations manual requirements already described in Chapter 2 on: ●
Housekeeping procedures: The general conditions are part of House manuals for Project Site Enclosures, prepared by a team of Project Managers:
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Safety procedures including emergency evacuation procedures Environmental conditions to be maintained in the calibration area Fire-fighting utilities Compressed air, water conditioning, etc. for use in calibration Air-conditioned environment requirements Stable power supplies’ requirements Personal Protective Equipment (PPEs) use Storage of hazardous material, etc.
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However, the Method Statement for I&C Technical works should be segregated as follows for ease of work and review in line with activity-based WBS: – Method Statement for Calibration – Method Statement for Field Installation – Method Statement for Control room works – Method Statement for Loop check – Method Statement for Pre-commissioning – Method Statement for Commissioning: d) Plant Site survey e) Plant Safety Plan review f) Site Operations Manual review g) Sequence of Works review A visual inspection of item / material is followed by segregation of damage-suspected or defective goods. Then a record is taken of the complete name-plate detail with tag. A comparison with the latest Data Sheet and Vendor Purchase Order is then made and discrepancies from name-plate details are highlighted in a report, for action by the Contractor or Owner to Vendor. Generally, consumable spares and parts of the same package are also listed along with name-plate details. In effect, a material card is opened either as a hard manual card or database card for the tag. h) Sequence of Activities Review – by Area and Site front availability Although installation is the first sequential construction start activity, it is usually the Prefabrication and Calibration activities at the instrument site workshop that kick-off the first works. i) Skill / Trade Test Certificates Review – of SITE works personnel j) Critical Path Review k) Onsite and Offsites Works Review l) Overall QA/QC plan and Report Format Review Generally, the QA/QC step starts with recording of Visual Inspection, taking a picture of the name-plate details, compiling the latest revision of the Data sheet or the inputs from the Data sheet required for calibration of Range and Limits, etc. m) Inspection and Test plan (ITP) Review A typical sample of ITP is shown in Figure 3.4. Detailed usable forms are issued under Chapter 6.
Figure 3.4 Typical Inspection and Test Plan.
3.1 General
Figure 3.4 (Continued)
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Figure 3.4 (Continued)
3.2 Site Estimations and Preparations – I&C 3.2.1 Information Compilation a) I/O Inputs (see Table 3.3). Table 3.3 Input / Output information.
3.2 Site Estimations and Preparations – I&C
b) Installation – Field (see Table 3.4). Table 3.4 Field Installation Quantity information.
c) Installation – Control room (see Table 3.5). Table 3.5 Control Room Works information.
d) Controls and Logics (see Table 3.6). Table 3.6 Controls and Logics Quantity information.
Note: All the information in Tables 3.1 to 3.6 are representative only and incomplete.
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3.2.2 Man-Hour Estimate (Table 3.7) Table 3.7 Man-hour Estimate.
3.2 Site Estimations and Preparations – I&C
3.2.3 Typical Engineering Cost Estimate Master Sheet (Table 3.8 and Table 3.9) Table 3.8 Construction Cost Estimate form - Field.
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Table 3.9 Typical Engineering Cost Estimate form – Control room works.
3.2 Site Estimations and Preparations – I&C
3.2.4 Documentation to be Available at Site All documents are critical for the operation of the site. It will be the responsibility of the Site Manager to ensure that the latest revisions of these documents are available at the site office. A list of a few critical typical documents is given below: ● ● ● ● ● ● ● ● ● ● ● ● ●
Contract Specification Hard copies of all drawings approved for “Construction” Hard copy of the database and soft copy Hard copies of all Manuals Hard copies of User’s manuals for equipment purchased from other vendors Construction and hand-over schedule Shut-down schedule Personnel-at-site Register (including Subcontractors) Records of Accidents and Lost-time due to accidents Register Active Clearance certificates Site Operations Manual Commercial conditions Copies of all forms.
3.2.5 Tools, Tackles, Test Instruments / Equipment Miscellany Generally, Key Site Engineers may have a week’s orientation at the Design Office, wherever feasible. Site Engineers must keep closely in touch with the Design Office and obtain clarifications, to resolve incidents and technical problems, etc. For these reasons they need to be adequately supported. The requirements may vary from site to site. Typically, the list may include: 1)
2)
3)
General 1.1 A Laptop PC for each Site Engineer, together with a modem with passwords and network controls on communication 1.2 A telephone connection for each PC 1.3 Soft storages (e.g., a Hard Disk) for archiving data 1.4 A steel cupboard (lockable) to store spares, etc. 1.5 Mobile telephones for each Site Engineer 1.6 A desk for each Site Engineer 1.7 A larger desk for spreading drawings 1.8 A designated meeting / conference room with telephone for conference calls Testing Tools and Calibration Instruments 2.1 All tools used in a classified area must be intrinsically safe or suitable for hazardous areas, especially at the time of Pre-Commissioning / Commissioning. 2.2 Calibration Instruments shall have been certified and traceable to primary standards, such as NIST or certified by NPL (see Table 3.10). Mobile Phones and Laptop for Hazardous areas Increasingly, mobile phones and laptops are used as construction tools for various functions up to pre-commissioning stage. These (apart from construction references on screen instead of hard copy drawings) allow for Construction reconciliation management, Check Form updates, QA/QC Record updates, Field construction data analysis, allow construction planning diagnostics and ensuring on-site safety.
(Note: Helmets, Gloves, Goggles, Shoes, etc., part of PPE is not listed here.)
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Table 3.10 Testing Tools and Calibration Instrument.
3.3 Field Installation 3.3.1 General 3.3.1.1 Overview
a) The main Installation reference standard is API RP 551 – Process Measurement (latest edition). Included inside this standard are several useful normative references of other standards on Installation The other useful information reference relevant to Field Installations is “Process Industry Practice – Process Control Installation” (PIP-PCI), which provides several illustrative drawings but not necessarily followed exactly except as a guideline, as its North American practices / fitments are not compatible with regional or international industrial practices. ● ● ● ● ● ● ● ●
PIP PCIDP000: Differential Pressure Installation Details PIP PCIEL000: Instrumentation Electrical Installation Details PIP PCIFL000: Flow Measurement Installation Details PIP PCIGN000: Instrument Pipe Support Installation PIP PCIGN001: General Instrument Purge Details PIP PCIIA000: Instrument Air Installation Details PIP PCIPA001: Process Analyser System Field Installation PIP PCIPR000: Pressure Installation Details.
b) Section 3.3 on Field Installation – Instrument Auxiliaries and Accessories covers the following topics associated with Field Installation:
3.3 Field Installation
A. Equipment and Manpower Requirements B. Instrument Mounting C. Accessibility D. Instrument Stanchion Installation E. Instrument Sunshade Installation F. Instrument Tag Plate Installation G. Field Boxes and Panels. These include installation of items such as Junction Boxes, FF Segment Boxes, Multiplexer cabinets, Trunk Boxes and Local Control Panels. H. Instrumentation Cabling I. Cable Glands J. Cable Routing and Terminations K. Instrumentation Earthing L. Instrument Impulse Tubing M. Instrument Air Piping and Pneumatic Transmission N. Instrument Hydraulic Transmission. 3.3.1.2 Equipment and Manpower Requirements
In order to complete Field Installation works, the Contractor shall employ the following equipment, tools and manpower, as shown in Table 3.11. Requirements may vary based on the nature of the job and the contract scope of the work. 3.3.1.3 Instrument Mounting Locations
1) All instruments shall be mounted as closely as possible to the process connection, provided that maintenance and accessibility requirements are taken into account 2) The length of the impulse line shall be optimally minimal, consistent with good practice and accessibility based on location 3) All transmitter’s local Indicators are to be readable Table 3.11 Typical Equipment and Manpower requirements.
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4) The location of Instruments shall be designed in such a way that direct drainage / vent of condensate, water, gas or process fluids from adjacent equipment have no adverse effect 5) Field instruments and electronic transmitters shall be mounted on independent pipe stands or attached by brackets to suitable steelwork and / or concrete structures. These instruments shall be mounted with a centreline at approximately 1500 mm (1800 mm maximum) above the platform or floor, in a position accessible for operation and maintenance, as per accessibility levels defined in Table 3.12 6) Exception shall be made for close coupled and in-line instruments; these shall be mounted on the pipe as per P&ID / isometrics. Escape and maintenance routes shall be taken into account for the final design and installation 7) The top of the pipe stand shall be plugged or sealed to prevent water entry. 3.3.1.4 Accessibility
Accessibility “identifies the minimal effort required for a healthy human being to reach instruments such as measuring elements, instrument process connections, instrument utility connections, block valves or sampling points for the purpose of operational attention and / or maintenance”. It includes the ability to reach such instruments with all tools required to perform operational attention or maintenance. The following four accessibility levels are defined: 1) Permanent Instruments are considered permanently accessible if they are located not more than 500 mm horizontally away from and not more than 1800 mm vertically above grade, platform or walkway, if no obstructions are in place and if such locations can be safely reached from those levels during plant operation 2) Limited Instruments have limited accessibility if they are located not more than 1000 mm horizontally away from and at a height between 1800 mm and 4000 mm above grade, platform or walkway, if no obstructions are in place and if such locations can be safely reached during plant operation by means of a mobile platform or ladder 3) Poor Instruments have poor accessibility if they are located more than 4000 mm above grade, platform or walkway or at any other location that can only be safely reached during plant operation by installing temporary facilities such as scaffolding and / or cranes. Instruments are also considered to have poor accessibility if they can only be reached after removal or disassembly of other devices or components, such as thermal insulation or equipment noise hoods. Sensing elements with remote transmitters shall be provided 4) Inaccessible Instruments are considered inaccessible if they cannot be safely reached during plant operation for the purpose of operational attention and maintenance. Table 3.12 provides minimum accessibility requirements; local situations such as labour costs may justify deviating from these requirements. Generally, Safety Instruments are mandated to have permanent accessibility (or deviation approved by the Owner). The general criteria for mounting location selection are as follows: i) ii) iii) iv)
Instruments connected to a protective system with a test interval of two years or less shall be permanently accessible Instruments shall be mounted on a vibration free spot. Special care shall be taken for heat expansion and cold spots Local converters, amplifiers, switches, etc., shall be installed near the corresponding instrument Local indicating instruments shall be readable from where the related equipment is operated or from where the primary instruments are to be tested or calibrated v) Instruments shall not be mounted directly on handrails vi) Instrument stands, plates welded / bolted / clamped to structures, yokes and similar support arrangements shall be used for mounting of off-line instruments. Instrument supports fixed to process piping or vessels shall not be allowed vii) Instrument supports and other steel supporting materials shall be hot-dip galvanised according to applicable specification. In a severe corrosive environment, PVC-coated materials shall be used
3.3 Field Installation
viii) In addition to the above requirements for package unit, cabling and tubing installation, interface boxes and bulkheads, location drawings and applicable package unit specification must be consulted due to confined space. In general, Pre-Package equipment location design is based on vendor recommendations ix) Instrument Special Protection may be required and locations need to be carefully chosen accordingly in special cases: In certain process / environmental conditions, it may be required to install controlled heaters / thermostats, Instrument (Heat) Tracing (e.g., to avoid Hydrate formation), as specially marked on the P&ID / Instrument Index. Heat tracing of instruments require ample space, whether by steam or electrical tracing, for tubing with insulations. Provisions need to be made for them at site.
Table 3.12 Instrument Accessibility Guidelines.
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Table 3.12 (Continued)
3.3.2 Field Installation – Instrument Accessories 3.3.2.1 Instrument Stanchion Installation
The following installation steps are to be followed and provisions for accessories and auxiliaries are to be planned as indicated below: 1) Preparation of the ground surface with foundation and grouting as per typical support details 2) Checking the elevation level, exact location orientation and facing of instruments as per instrument location layout and 3D model documents 3) Ensuring the line-of-sight checked with alignment kit for all the Fire & Gas (FGS) Detection and Protection Systems detectors, as applicable 4) Sunshades shall be provided to all instruments which are directly exposed to sunlight. Skid mounted instruments under the shelter or roof shall also be provided with a sunshade when they are exposed to sunlight. These require additional supports 5) The stand has to be fixed in such a way that process connections are on the same side of the equipment so that Impulse tubing will be as short as possible 6) Control valves and on-off valves shall be mounted in such a way that all their accessories, valve position indicators and hand-wheels are easily visible and accessible from grade, walkway, platform, etc. Portable ladders shall not be presumed for use to access the valve and its accessories. So, fixing of all stanchion supports for auxiliaries / accessories shall take into account spacing, interference to operation and accessibility, etc. 7) Cables connected to instruments shall be installed with a loop of cable to provide sufficient slack for remaking the cable connection if the instrument is relocated in the future and to allow removal of the instrument without disconnecting the cable. These may require additional tray support on a stanchion to be welded / clamped
3.3 Field Installation
8) An instrument earth cable shall be connected to the instrument, stanchion and to the plant instrument earth system. Also, provision on the stanchion is required with ground lugs 9) Instrument stanchions are galvanised and it is important to ensure galvanised parts integrity during installation 10) After instrument mounting, all the sharp edges shall be filed, and all the damaged portions shall be applied with galvanising touch-up paint 11) Instrument tag plates shall be installed on the stanchion – not on the sunshade. An additional tag plate shall be provided on the instrument. The Instrument tag plate is required to be fixed on the stanchion with proper screw / bolt 12) All the vendor supplied skid mounted instruments may be removed from their skids, shop calibrated and reinstalled on their skids. Where required, re-installation on site may need additional supports, foundation, sunshade, earthing, tag plates and readjustment of the instrument orientation as appropriate. However, in most cases, as mentioned earlier and as a general practice, Packaged Equipment Instrumentation and Panels on a Vendor supplied skid are left undisturbed and are usually as per Vendor recommendations, in view of Packaged equipment warranty / guarantee integrity. The stanchions were once usually fabricated on site. However, these days, due to high levels of detailed Construction Engineering at the home office, the procurement is also done from the home office for pre-fabricated stanchions with item rates for additions planned for site procurement. Specification for stanchions and assistance for site fabrications are included under Chapter 4. The details for supports and stanchions for mounting of boxes is included elsewhere. The following are the typical instrument stanchion Installation arrangements that may be followed during site execution (see Figures 3.5 to 3.7) and referenced later under Chapter 4. A detailed Bill of Materials (BOM) used for fabrication is also included in the fabrication drawings by the Contractor, as shown in Table 3.13.
Table 3.13 Typical BOM for Stanchion.
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200
4
BLIND FLATE (MIN.. 2.0)
7
TAG PLATE FLAT IRON 150 x 30
800
1700
EARTH LUG FLAT IRON 02-20 1 2 in. PIPE 1000
3 200
REINFORCEMENT QTY: 4 @ 90 deg. BASE PLATE 2 250 x 250x 6t 2
A
INST. CENTER LINE
INSTRUMENT STANCHION
TAG PLATE
EARTH LUG 200
102
S
L-50x50x5t Steel Plate 6
DETAIL A
Figure 3.5 Typical Instrument Stanchion – for Yoke or surface mounted Instrument.
(180V x 180H x 45t)
3.3 Field Installation
Figure 3.6 Typical Instrument Stanchion – for Multiple Instruments / accessories.
For other stanchion mounting possibilities, see Figure 3.7. 3.3.2.2 Instrument Sunshade Installation
1) All the electronic field instruments, electrical / electronic instruments (sometimes even for SOVs, Limit Switches and Positioners) and Local Control Panels (LCP) mounted in open areas are to be provided with a sunshade or cooler 2) The requirement of a sunshade for field instruments and LCP inside the shelter is reviewed during the construction stage. However, pneumatic instruments (actuators), gauges, etc., do not require a sunshade 3) Mounting brackets for instruments shall be selected in such a way that instrument installation will not obstruct the sunshade and the instrument will not be directly exposed to sunlight. Mounting brackets and all accessories shall be of corrosion-free metallurgy. Necessary non-conducting sandwich material, such as some kind of rubber / Teflon beading, are provided between bracket clamp and stanchion to avoid galvanic corrosion
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Figure 3.7 Typical designs for other Stanchion Mounting possibilities (InTools - Intergraph Corporation). Note: Figure is representational for broad understanding only - Parts legend & detail not provided deliberately.
4) Sunshade and mounting bracket installation shall not obstruct the instrument display and the display shall be clearly visible to the field operator 5) The sunshade shall cover the instrument on all three sides and top from direct exposure to sunlight 6) The sunshades made out of MS Steel are usually fabricated on site and then painted or galvanised as per project specifications / requirements 7) UV-resistant Polyester sunshades are bought as moulded and fabricated However, these days, due to the high level of detailed Construction Engineering at the home office, procurement is also done from the home office for pre-fabricated sunshades with item rates for additions planned for site procurement. Specification for sunshade fabrications is included under Chapter 4. 8) Figure 3.8 shows the typical instrument sunshade installation arrangements that are designs used / fabricated on site.
Figure 3.8 Sunshade designs for on-line, off-line and in-line Instruments.
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3.3.2.3 Instrument Tag Plate Installation
1) All field instruments shall have the following name-plates: Name-plates, showing tag number, shall be of a permanent type, firmly fastened, preferably indicated on the Manufacturer’s name-plate. Even if the tag number is shown on the Manufacturer’s name-plate, a name-plate (with tag number) shall be fixed to the instrument with a chain at site 2) All tagged field instrument equipment shall be fitted with a “Resopal” or equal raised profile, anti-bacterial, high-pressurelaminate (HPL) label marked with tag number and service as minimum, and shall be installed on the instrument support 3) All control valves, on / off valves and safety relief valves shall be provided with hanging tag plates on the valve body. Additionally, some provide a tag on the pipe line installed with the properly designed mechanism such as wrap-around straps 4) Tag plate colour shall be as specified in project specifications – white in general for all service; except for ESD/SIS and FGS service it shall be red. Where one instrument or valve shares both DCS and ESD signals, priority shall be a red colour tag over white. This philosophy shall be applied to field instruments, local gauges, transmitters, junction boxes, local control panels, valves, analysers, all remote building mounted instruments, etc. 5) Inside buildings, an instrument tag plate shall be mounted on the properly designed bracket, not directly onto the wall 6) Materials used to fix tag plates such as chain, nut / bolt, rivets, etc., shall be SS 316 minimum 7) A local control panel, where both process control and ESD signal equipment are provided in one cabinet, shall have white and red colour tag plates for the items / signals based on the service it employs. The name-plates are usually part of site procurement from local engravers, as permanent fixing is usually after inspection of installation. Note: Generally, during instrument installation inspection, permanent name-plates may be an item to be inspected for correctness of tag number, description of process, etc., as per some company practices and hence may be required to be installed earlier. Specification for name-plates as a guideline is included under Chapter 4. 8) Figure 3.9 shows a typical instrument name-plate arrangement. 3.3.2.4 Field Boxes and Panels Installation
(Junction Boxes / Segment Boxes / Multiplexer Cabinet / Trunk Boxes / Local Control Panel Installation) Figure 3.9 Typical Field Instrument name-plate.
3.3 Field Installation
Field Boxes in use in the industry are specified for a wide variety of types to suit the selected instrument cables for the Hazardous area classification concerned; and of various materials of construction including many accessories like hinges, mounting brackets, clamps, DIN terminal rails, Earth-stud, drawing pocket, breather / drain, nuts / bolts, hinged doors, etc. (sometimes loosely supplied). Therefore, a partial assembly work is required and a visual inspection of the boxes is also required. A sample mounting support fabrication on site is common, prior to site installation. This helps in reducing too many custom supports’ fabrication and regularises the fabrication procedure for speedy work. The boxes and local panels are usually designed, engineered and procured from the home office. However, these days, the procurement is also done from the site office after site engineering by the Contractors. To enable this, Typical Specification for standard Junction boxes is included under Chapter 4. This section essentially deals with Installation requirements. However, the Installation details provide detailed information on site fabrication work of supports and stanchions to install boxes. F1–Installation of Field Boxes: 1) As stated in the Introduction, sample assembly and installation are prepared for each type of box, inspected and approved for plant-wise installation as model assembly 2) Especially important for safety, all boxes must be checked as provided with an internal and external earth bolt (minimum M8, when not specified), for safety earth (PE) connection; and support and dress-up of earthing wire is to be anticipated 3) When required to mount near a duct, a minimum of 50 m from the edge of the duct to the side of the enclosure is allowed 4) Boxes shall be mounted with a centreline at approximately 1500 mm above grade / platform 5) Enclosure name-plates and labels are to be fixed with screws 6) The installation works are as per Client’s approved installation drawings 7) The grounding surface is prepared with foundation and grouting shall be as per typical installation hook-ups 8) The elevation level, exact location orientation and facing of boxes as per instrument location layout and 3D model documents are also checked 9) A sunshade shall be provided to all boxes where a box consists of electronic equipment such as field bus segment, power supplies, etc., if those items are not rated for temperature limitations of the installation site. Usually, this is evaluated during the project engineering and procurement phase and the sunshade is assembled by the box vendor themselves to avoid refabricating on site 10) Junction box stanchions shall be fabricated on site. All details as mentioned for Instrument supports are also applicable to box supports. After junction box mounting, all the sharp edges shall be filed and all the damaged portions shall be applied with galvanising touch-up paint 11) Junction box tag plates shall be installed on each junction box, not on the sunshade; Tag number only on the stanchion sometimes if customised. An additional tag plate may be provided on the stanchion to identify the junction box location when it is removed for any maintenance work. Figure 3.10 shows typical junction box mechanical installations designs on paved and unpaved structures.
Figure 3.10 JB installation details.
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Figure 3.10 (Continued)
3.3 Field Installation
F2–Local Control Panel installation: 1) The internals of a Local Control Panel, provided as part of the packaged unit, shall be inspected for appropriate internals and must contain simple instruments only, e.g., indicators, switches, lamps. The inclusion of electronics in the local panel, such as logic controllers or annunciator logic, shall not be allowed unless it is within a building / weather rated enclosure. It may be relocated after consultation and Owner approval 2) The local panel is located on the equipment skid or close to the unit. Therefore, special consideration shall be given to proper protection for high thermal radiation humidity, vibration, etc., at the site area 3) The Local Control Panel shall be provided with area lighting equipped on the stanchion head for operational purposes. Installation must anticipate and provide for such facility during construction 4) All instrumentation and equipment to be installed inside of the panel shall be protected so that they can function properly under the environmental conditions. Temperature rise due to extreme ambient conditions shall be fully considered Sunshades (304 SS) and Weatherhoods (304 SS) shall be provided over all local panels / gauge boards. 5) Local Control Panels are to be mounted in a separate independent stanchion / structure at safe and vibration-free locations 6) E Exp (Purging) techniques are used where no practical alternatives exist. The installation of the purge system shall comply with NFPA/IEC to pass certification 7) No process fluid shall be piped into the enclosed panel 8) Redundant Earth lugs provided shall be used 9) The Local Control Panel of the Instrumentation system shall be dedicated and separated from the local control panel of electrical system installations.
3.3.3 Instrumentation Cabling Installation 3.3.3.1 Importance of Specification in Cable Laying
Note: This section includes basic specs necessary to keep in perspective during Installation but for complete specs suitable for field procurement use, please refer to Chapter 4. 1) Field mounted electronic instruments are wired and connected to instrument boxes by means of single cables. Instrument cabling between the instrument boxes / cabinets and instrument racks / system cabinets in buildings are by means of multi-cables 2) In the case of special signal transmission requirements for field mounted instrumentation, direct home run (single) cables are used (e.g., frequency signals) 3) All conductors in Instrument Multi-core, Pair/s or Triad/s are usually stranded, except in power cables to Instruments. Conductors on single cables are also stranded. Single cables also are specified with a screening of metallic-Polyester tape with a drain wire. Also, all signal wires are specified as twisted in Pair/s or Triad/s. Pair/s or Triad/s shall be numbered along the length of each conductor 4) In cables serving instrumentation-related signals, cable joints (splices) shall not be used. Splices are not permitted in wiring. When wiring must be extended, connections shall be made via terminal blocks in a junction box installed aboveground 5) Multi-core cables have an overall screening of metallic tape with a drain wire. Multi-pair, or Multi-triads including Foundation Fieldbus and other special instrument signal cables (e.g., pulse) or when required by system manufacturer, are additionally with an individual pair / triad screening of metallic-Polyester tape with drain wire. Furthermore, all field instrument cables shall be provided with steel wire armour or steel wire braided armour, depending on installation requirements 6) Instrument Signal cables and Instrument Power cables are specified and purchased and made available on site as cable drums 7) All cables shall be water, oil and sunlight resistant, gas and vapour tight and at least Flame Retardant as per most specifications 8) All cables (above-ground and underground, inside and outside of fire zones) are Fire Resistant 9) All cables used for Intrinsically Safe signals require segregated installations and terminations as per project requirements and specifications 10) In the case of Foundations Fieldbus (FF) instruments, the applicable instrument signals shall be wired to segment boxes by means of single cables. The segment boxes shall be directly wired and connected to dedicated FF boxes. Cabling between FF boxes and instrument racks / marshalling cabinets in buildings shall be by means of multi-cables.
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11) 12) 13)
14)
Foundation Fieldbus Type A cables and Fibre Optic cables are usually Flame Retardant, while Foundation Fieldbus type A cables connected to MOVs are usually specified as Fire Resistant additionally For interconnection of cable screens, the screening shall be earthed such that multiple earthing does not occur. If applicable, specific project Electro Magnetic Compatibility (EMC) guidelines shall be followed Cable glands on junction boxes / equipment in the field shall by default be mounted at the bottom to prevent ingress of water The cable specifications and Data sheet documents are checked against cable drum details, as a wrong cable laid as main run or trunk run would be a big construction hiccup. Several factors on installation such as bend -radius and other particulars (proper glands, suitable cable lugs, etc.) are relevant to installation and the terminations part of Installations work for good cabling works. The requirement of individual cable conductor sizes is relevant for Installation and Terminations – and so project specifications and cable Data sheets provide this information. Vendor instructions shall be followed for installation and connection of Special Signal-Cables such as coaxial cables, Fibre Optic Cables, etc. To further ensure proper installations, the cores of the cables are colour coded. Typical core identifications by colour are provided, as given in Table 3.14), but design documents need be verified (e.g., wire colour coding for FF 3-cores can be Brown, Blue and Green, with Brown +ve, Blue -ve and Green (earthing))
Table 3.14 Cable Colour Coding.
3.3 Field Installation
15) Before laying a cable, distance metrics are performed and verified and a slack provided as a percentage of run length but subject to a maximum. The cable lengths also have an effect on installations permitted. Power consumptions tables, Voltage drop calculations and Ex “i” Loop calculations are re-checked by Site Engineering for typical or worstcase scenarios listed in the cable schedule and instructions are passed on to cable technicians 16) Instrument compensation cable used for T/C shall be as per standards (i.e., ISA / IEC shall be used for Thermocouples) or with remote mounted transmitters 17) In general, standard instrument cable may be used for Telecom signals, but some Clients use International Telephone and Telegraph (ITT) specified cables, and so Vendor instructions shall be followed for installation metrics 18) Foundation Fieldbus System Engineering Guidelines such as AG-181 are to be followed for installation of FF cables 19) Cable tagging and numbering shall be followed as per approved design and engineering documents, schedules and drawings. Examples may be referred to in the following typical details provided 20) Cable entry into Control room: a) Cable entry into the Control room preferably uses Multi-Cable Transits (MCTs) or use HDPE sleeves (sealed with Bitumen at entry and exit after cables are laid) b) Usually, the field cables upon entry on the MCT are stripped of the outermost sheath and metal armour c) After stripping, connect all armour to Earth terminal d) There is no harm in exposing the inner sheath if all cables are under false floors that may be laid on trays. Covers over the trays hinders the smooth flow of cables to individual racks. At the panel, single Compression gland or Metal Grommets and Cable Clamps may be sufficient. A 100/150 mm-wide flat below racks / panels may help guide the cables into panels before clamping them at panel entry e) However, the armour is not stripped if entry is into Packaged small rack rooms at MCT, for reasons of mechanical protection f) If rodent issues are likely, the armour is not stripped at MCT unless space is a constraint 21) Fibre Optic cable (FOC) Installation: The Fibre Optic cable installation and Fibre-splicing is a specialist’s job. Detailed procedure for Installation by Contractor is usually provided for both in the Plant area and inside buildings. Plant area installation can be in paved areas, unpaved areas, built-up trenches, ducts, buried pits, etc. However, inside buildings, it is usually placed in PVC ducts or HDPE sleeves / ducts and preferably orange-coloured. a) Splicing shall be carried out using a calibrated Fusion-splicing machine and a Fibre Optic cleaver. The splicing joint is usually carried out in an environmentally controlled setting and cleaning solution; and other materials used shall be suitable for FO cable. Each joint-splice loss shall not exceed ≤0.1 dB, and splicing details of all the joints shall be properly documented b) During jointing, electrical continuity of each of the metallic layers in the cable shall be maintained c) A padding of sand / soft soil is done covering the FOC and some countries require a warning mat (PVC / Plastic sheet, orange colour, with warning in Black-on-White mentioning “Fibre Optic”) is to be placed d) Some guidelines are given below: i) Statutory approvals may be required for reasons of National Security from Local Governments, for Cyber Security issues. Perimeter CCTV is one such normal requirement for projects of national importance ii) FOC, if installed in a separate trench, requires a minimum depth of 0.6 m and a minimum trench width of 300 mm iii) Before laying the cable, soft padding of sieved sand or soft soil is provided iv) All crossings are through an HDPE conduit and an HDPE conduit shall be sub-ducted in a casing conduit v) Crossings of utility / service are specified at least 0.5 m above the utility service. The PVC/HDPE duct extended for 5 m either side of the crossing is the usual arrangement. All crossings are provided with a spare HDPE duct suitably sealed for future use. However, at road crossings, the PVC/HDPE ducts are encased in concrete vi) Inside the boundary walls of the Control room / buildings, the FOC laid in independent HDPE sleeves is preferably located along the walls to its Splice / FO converter box, where it becomes converted into copper cables; and preferably with MCTs across all rooms. Slack and Loops are to be provided in each wall crossing and at the end to facilitate termination vii) Fibre Optic cables may be installed in all categories. However, installation in Category 2 with instrumentation cable or separate Fibre Optic cable network routing is preferred. Installing Fibre Optic cable with electrical cables shall be avoided as much as possible.
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Note: Instrumentation cables are treated as long delivery items and seldom procured on site, except if there are small add-ons to projects that are developed by in-house plant maintenance. The specifications are part of Detailed Engineering. However, there is always a need to review at the construction stage the quantities on field measurements and shortfalls are then made up by site procurement. However, a good perspective on the minimum design specification requirements of cables is needed for every Construction I&C Engineer as they are the backbone on which the I&C plant depends. So, a brief cable specification is also included under Chapter 4. 3.3.3.2 Cable Glands Installation
1) Cable glands are selected such that they suit the selected instrument cable and are also suitable for the hazardous area classification concerned. They differ in their usage for say Ex e vs. Ex d, etc. Therefore, care and attention is paid to installation of cable glands and their appropriateness to the enclosures, as Plant Safety Certifications are involved. For example: a) For Ex “d” instruments (if the cable enters directly into an Ex d enclosure), the Ex d cable gland is with a barrier compound. Barrier compounds shall be filled after successful continuity test of the cable, prior to loop test b) For all other classifications (Ex i, Ex e, etc., and for Ex d instruments if the cable is connected to a non-Ex d compartment), a barrier compound is not required c) Interchanging would void safety certifications and endanger the plant d) Shrouds, if required by company standards on cable glands, shall be provided. 2) Earth tags shall also be provided on cable glands. The specification of cable glands is included under Chapter 4. Field cable glands for junction boxes are usually ordered with boxes as fitted under the same specification. While cable gland estimates are easily done for field equipment under detailed engineering, it is the Control room panel cable gland estimations that frequently go awry and require a good estimation check on site based on home runs and inter-panel cabling. 3.3.3.3 Cable Routing, Supporting and Fastening Installations 3.3.3.3.1 General
Instrumentation, control cables and data highways in the field may be routed either aboveground, underground or a combination of both. However, the following general principles are practiced by many companies. In cable laying, the following points merit individual consideration and are described in subsequent paragraphs: ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●
Signal segregation Cable routing methods Cabling from field instrument to field junction box Cabling from field junction box to Control room marshalling cabinets Above-ground cable supporting system Cable tray system Conduit, conduit fittings and supports, if applicable Cable fastening Underground cable supporting system Cables in trenches and / or ducts Duct bank Cable entry sealing and multi-cable transits (MCTs) Cable termination Noise and signal interference reduction Cable glands installation Connections at field instruments Connections at field junction boxes Termination (methods, terminal blocks, terminal strip assemblies, wire ducts and gutters) Identification (wire tagging, cable tagging and terminal reference).
3.3.3.3.2 Cable Signal Segregation
Cable signal segregation is critical for proper cabling Installations.
3.3 Field Installation
Most companies categorise cables (without reference to any standards) as below: B1. Application-based cable segregation – Analogue signal approach: Table 3.15 Cable categorisation.
B2. Standard NSL-based levels However, increasingly, instrument cables are grouped according to the signal types by an IEEE standard on Noise Susceptibility Levels (NSL), as increasingly globalisation and digitalisation are in vogue and the line between communication and sensor signals is blurring. Many consulting companies were following their own classification – some up to five levels based on risk severity of plants, as in Table 3.15. However, a standard exists that allows instrumentation cables to be categorised based on noise susceptibility levels (NSL) of “1”, “2” or “3”, as per IEEE 518. Note: Noise susceptibility level ratings and separation tables are derived from IEEE 518 Guide for the Installation of Electrical Equipment to Minimise Electrical Noise Inputs to Controllers from External Sources. The IEEE 518 standard defines three noise susceptibility levels for instrumentation signals; however, due to the signal levels commonly used in facilities, it is deemed that two noise susceptibility levels are adequate.
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Level 1 – High to Medium Susceptibility: Analogue signals of less than 50 V and discrete instrument signals of less than 30 V Signal Types: a) b) c) d) e) f)
Foundation Fieldbus 4–20 mA and 4–20 mA with HART RTD Thermocouple Millivolt / Pulse Discrete input and output signals, e.g., pressure switches, valve position limit switches, indicating lights, relays, solenoids, etc. g) All wiring connected to components associated with sensitive analogue hardware (e.g., strain gauge) h) Copper data links (RS-232 or 485). ●
Level 2 – Low Susceptibility: Switching signals greater than 30 V, analogue signals greater than 50 V and 120–240 AC feeders of less than 20 amps Signal Types: a) Discrete input and output DC signals, e.g., pressure switches, valve position limit switches, indicating lights, relays, solenoids, etc. b) Discrete input and output AC signals, e.g., pressure switches, valve position limit switches, indicating lights, relays, solenoids, etc. c) 120–240 AC feeders of less than 20 amps.
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Level 3 – Power: AC and DC Buses of 0–1000 V With Currents of 20–800 Amps (Not part of I&C)
B3. General notes on Signal Segregation I) However, even as per IEEE standard, multi-pair / triad I&C cables shall not be used to route more than one signal type. In addition, junction boxes shall be segregated based on signal type (e.g., each signal type shall have its dedicated junction box) II) Cables with the same Noise Susceptibility Level may be grouped in trays and conduits (e.g., all level-1 cables may be routed in one cable tray) Exception: RS-232/485 and other copper communication cables (other than FF) shall be routed in dedicated conduits and trays for functional segregation purposes. III) When routing instrumentation and control signal cabling (NSL level 1 or 2) near sources of strong electromagnetic fields, such as large transformers, motors and generators, defined for purposes of this standard as greater than 100 kVA, a minimum spacing of 2 m shall be maintained between the cables and the devices IV) When entering terminal equipment (e.g., Motor Control Centre) and the spacing listed below in tables cannot be maintained, parallel runs shall not exceed 1.5 to 2 m in the overall run. (Some companies alternately follow the 10% rule, i.e., 10% of the main run length but not less than 2 m and not more than 6 m for onshore cabling). V) Minimum separation requirements between various instrumentation cables and Fibre Optic data link cables shall be per the manufacturer’s recommendation VI) When routing instrumentation cables (NSL level 1 and level 2) near power cables carrying higher loads than the limits specified in level 3, the separation distances shall be 1.5 m as a minimum as states above. Due to space limitation on offshore platforms, the separation distance between NSL-1&2 instrumentation cables and power cables above NSL-3 shall not be less than 1 m for parallel runs and 650 mm for cable crossing at 90 degrees VII) Power cables and instrumentation cables shall cross at right-angles (90 degrees) while maintaining the required separation distances as per the tables provided below. 3.3.3.3.3 Cable Routing Methods
C1. Cabling From Field Instrument to Field Junction Box
3.3 Field Installation
Cable between field instruments and junction box shall be routed aboveground, utilising one of the following options: a) Conduit Unarmoured Single twisted pair / triad cables are installed in hot-dip galvanised rigid steel conduits from the field instruments to the field junction boxes b) Cable Tray and Ladders Armoured instrumentation cable is routed on perforated cable trays or ladders. Single-pair armoured cables are not generally routed on cable trays / ladders but on channels and angles. The armoured cables shall be routed independently of main overhead systems used for “home-run” cables to Control or Auxiliary rooms. The unsupported end of the cable at the instrument shall be looped; this loop shall take into account the bending radius of the cable. The unsupported length of cable at the instrument shall be the minimum length required to provide the service loop. This unsupported loop in the armoured cable is required to provide sufficient slack for cable gland make-up and for easy removal of the cable from the device for future instrument change-out. 3.3.3.3.4 Cabling From Field Junction Box to Control Room Marshalling Cabinets
Cables, between Field Junction Boxes and Marshalling Cabinets / End Termination-Cabinets in Control or Auxiliary rooms, often called “Home runs”, may be routed in conduits, on trays / ladders or buried, preferably laid in built-up trenches. The trench details are covered elsewhere. Direct buried cables in the earth are generally avoided for Instrument cables and require lead sheathed / aluminium extruded cable layer to keep out seepages from the ground. 3.3.3.3.5 Aboveground Cable Supporting System
Aboveground instrumentation cables shall be run on a cable tray or in a conduit as detailed below. Aboveground is the preferred routing method within processing and underground for Offsite and Non-processing facilities. 3.3.3.3.6 Cable Tray-Ladder and Support Systems
1) Cable supports can be cable ducts, cable trays, ladder racks, closed trunking and dedicated steel profiles, and shall be divided into the following groups: ● Main cable or Long or Home-run cable supports are usually in cable tray / ladder racks with a minimum size of 300 mm ● ●
Sub-cable supporting meaning cable tray / ladder racks smaller than 300 mm Secondary cable supports can use dedicated heavy-gauge steel profiles / conduits / “Colson” strips, etc.
2) Default cable tray size selection as usually specified in design are usually 300 / 450 / 600 mm, with a minimum height of 100 mm. The NEMA 600 / 900 mm tray may need heavy stiffening if used and so preferably it is made as a cable ladder. All cable trays / ladders shall be of aluminium material 3) Cables in pipe racks are usually of the Ladder type, i.e., two longitudinal side rails connected by individual transverse members (rungs). The distance between consecutive rungs shall not exceed 229 mm (9 "). Ladder cable tray material shall be copper-free aluminium (or at the worst, aluminium with a maximum of 0.4% copper) 4) The cable tray system shall be installed with the Manufacturers’ standard fittings, clamps, hangers, brackets, splice plates, reducer plates, blind ends, connectors and grounding straps 5) All fasteners (i.e., nuts, bolts, washers, etc.) used to connect and assemble the cable tray system shall be 304 SS. In severe corrosive environments, 316 SS fasteners shall be used 6) Cable tray supporting armoured cables extending between field instruments and junction boxes shall be a bottom ventilated, channel cable tray 7) The channel cable tray shall be designed, manufactured and marked in accordance with NEMA VE 1 – 2002 8) The working load of the cable tray shall consist of the weight of the cables, plus a concentrated static load of 45 kg at the centre of the span 9) The static load can be converted to an equivalent uniform load using the formula in NEMA VE 1 – 2002. 10) The overall working weight shall not exceed the rated load capacity of the cable tray, as defined in NEMA VE 1 – 2002 11) In addition to the requirements listed above, the channel cable tray system shall generally meet the following: ● Channel cable tray width shall be 3", 4", or 6 " with a minimum loading depth of 1–¼ " ●
The channel cable tray system shall be installed with flanged covers
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The ventilated straight sections shall have slots (~3/16" × ½") to facilitate the use of cable ties to secure the cable(s). The slots shall repeat every 12–18 " The ventilated straight sections shall have splice holes, repeating every 12–16 " to simplify field modifications All fasteners (i.e., nuts, bolts, washers, etc.) used to connect and assemble the channel cable tray system shall be 304 SS. In severe corrosive environments, 316 SS fasteners shall be used The channel cable tray system shall be free from burrs or other sharp projections that could cause damage to the cable jacket during installation.
12) Cable supporting installations shall be adequately supported with a minimum of one support per 3 m installation. Next to every branch in the cable supporting system, a support shall be installed within 1 m. Wherever possible, the supports shall be arranged such that cables can be laid sideways into the tray / trunking instead of pulling them through consecutive holes 13) Free space over the tray, ladder racks and trunking shall be a minimum of 200 mm to ensure cables can be easily laid down during construction 14) Cable supporting installation shall be joined by bolts and nuts. Bolts shall be installed with the round head internally and the nut externally. All joints shall be smooth finished, so that no damage to cabling and / or tubing shall occur 15) The cable supporting installation shall not obstruct traffic, hoisting installations, nor interfere with accessibility or removal of process equipment such as pumps, motors and heat exchanger bundles, etc. 16) Sufficient expansion possibilities on cable supporting installations shall be provided for: ● Straight runs longer than 25 m ● ●
At dilatation joints in buildings or structures Runs in areas with large fluctuations in temperatures.
17) Redundant cables shall be routed via different paths in a diverse route so that single-point failure of both redundant cables shall be avoided; in the case of Fibre Optic cables, routing through an electrical trench shall be allowed 18) Cables and cable trays / ladders shall be routed away from hot environments and places with potential fire risks such as hydrocarbon process pumps, exchanger heads, burner fronts of furnaces and boilers 19) Those parts of the supporting cable, which shall be installed in places where they are liable to be damaged by plant fires, shall be provided with fireproofing, as specified in the applicable project specification. When the cables are fireproofed, i.e., Fire Retardant and Fire Resistant types, fireproofing of cable ways may not be required, unless specifically identified in the document 20) Cable supporting shall be located away from where they are subject to mechanical damage, spilt liquids, escaping vapours and corrosive gases. Where cable trays are liable to be damaged by traffic, they shall be protected by freestanding and sturdy mechanical structures 21) Cable ladders / trays shall only be mounted sideways and only horizontally with Manufacturer / Client approval 22) Rung distance of the cable ladder shall not be more than 300 mm. The length of the individual cable ladders shall be so that mounting or dismantling can be done with easily handled sections 23) Looping of cables shall be avoided; only in cases of ladder / tray expansion, looping of cables is required 24) Single overhead cable runs may be attached to steel work, secondary cable supporting systems like Colson strips, strut channels, etc., if they are not subjected to mechanical damage 25) Fasteners such as bolts, nuts and washers shall be at least of corrosion-resistant steel 316 minimum. They shall be resistant to the effects of the environment in which they are to be used and adequate for the load to be imposed upon them without undue stress or sagging 26) Fasteners shall be of the same material as supports, to avoid corrosion due to electrolyses 27) Bends in cable supporting systems shall be based on the minimum bending radius of the thickest cable, as advised by the manufacturer 28) Cable supporting shall be of a rigid design and self-supporting between holding brackets without excessive deformation after the cables are installed. Cable supporting shall at least be in accordance with manufacturer specifications based on maximum load 29) Cable supporting systems shall be designed and installed to ensure electrical continuity throughout the run and such that water cannot collect or remain in any part of the system 30) Bonding wires with bolted connections at coupling points shall be used for electrical continuity. Coupling plates of trays are assumed to provide proper bonding for the tray systems 31) Cable supporting system for secondary cable routing shall be adequately supported. Each piece shall have a minimum of two supports, and shall only be installed horizontally or vertically and parallel to the plant coordinates
3.3 Field Installation
32) Where cables are required to be installed through or across the edges of tray or other metal work, the edge of the lips shall be smoothed, protected from the environment and lined with a protective sleeve to avoid cable damage 33) All cable trays / ladders shall be closed with removable aluminium covers to counteract the following situations: ● To protect cables exposed to solar radiation ● ●
For protection against possible leakage or liquid For protection against mechanical damage during maintenance, e.g., on locations for equipment.
34) Turnovers ● Minimum of two straps / bands or equivalent shall be installed per single piece of cable supporting cover ●
Secondary cable supports shall be manufactured from good-quality heavy gauge steel, galvanised; preferably. “L”- or “U”-shaped profiles shall be used. They shall be protected from the environment in accordance with the applicable project documentation.
35) Cable trays / ladder design, fabrication and installation mostly follow NEMA VE1 and VE2 latest edition but there are other standards that are different. However, NEMA provides support design for reference extensively and may be preferred for any design. All the supports and accessories used for the cable tray system in corrosive environments shall be either PVC coated or rated / certified for suitability to install in such environments 36) Maximum filling of cable ladders / trays or trenches shall be 70% on “Approved for Construction” deliverables 37) Fibre Optic cables may be installed in all categories, installation in Category 2 with instrumentation cable or separate Fibre Optic cable network routing which maybe preferred. Although technically permitted, installing Fibre Optic cables with electrical cables may be avoided as much as possible, for reasons of access control permissions required from Electrical discipline 38) All in-plant process automation networks shall be redundant and shall be routed in separate cables. The Primary cable shall follow a different route from the Backup cable. Primary and Backup data link cables shall preferentially enter cabinets or consoles from opposite sides. Data link cables shall not be routed in the same conduit, duct or tray with other Instrument signal cables 39) When separate trays / ladder trays / ladders are impractical, NSL 1 and 2 cables may be combined. Separation shields shall be used to separate the signal groups. When NSL 1 category analogue 4–20 mA signal cables and discrete or power cables of 24 VDC signals (SOV, horn / beacons, etc.) are to be run side by side in trays / ladder-trays, and ladders are impractical for more than 1500 mm, a minimum distance of 150 mm shall be taken into account 40) The following table indicates the minimum distance in millimetres (inches) between the top of one tray and the bottom of the tray above, or between the sides of adjacent trays. For direct buried cable, or cables in PVC conduits, cable spacing shall be as shown in this table:
41) Electrical power feeder cables shall not be laid in the same cable tray / ladder as those of instrument cables 42) When power feeder cables intersect instrument cables the crossing shall be at right-angles, with a minimum separation distance of 300 mm 43) In general, cable clamps are be used to anchor multi-cables to panel frames or clamping under cabinets 44) Accessory cable support constructions – In general, specially manufactured iron construction parts such as angles and channels shall be hot-dipped galvanised in accordance with project requirements. Saw cuts and drill holes shall be touched up. 3.3.3.3.7 Conduit and Conduit Fittings and Supports Installation
The specification for procurement of Conduits and Conduit fittings is included under Chapter 4. 1) Conduits and Conduit fittings are generally followed to North American standards as is common there and wherever North American construction or consulting companies are involved throughout the world (allows use of unarmoured cable). Note: A broad-based installation requirement is only provided here, as many follow IEC-based armoured cable use only. NEC 500 may be referred for additional details. 2) Direct buried conduit shall be heavy duty PVC conduit. Concrete encased conduit may be plain PVC conduit too
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3) However, direct overground or buried conduit in electrically hazardous areas in NEC 500 Electrical Class I Division I areas shall be threaded, rigid steel, hot-dip galvanised and PVC coated. Conduit fittings for direct buried PVC coated rigid steel conduit shall be factory PVC coated 4) Conduit installed exposed (e.g., not embedded in walls) aboveground in outdoor, industrial facilities shall be threaded, rigid steel and hot-dip galvanised 5) Where flexibility is required, liquid-tight flexible metal conduit (in non-hazardous and Class I, Division 2 and Zone 2 hazardous locations) or explosion-proof neoprene coated or PVC coated flexible couplings (in Class I, Division 1 and Zone 1 hazardous locations) shall be used 6) Electrical Metallic Tubing (EMT) is acceptable only in non-hazardous indoor locations. EMT and its installation generally comply with the requirements of ANSI C80.3 7) Intermediate Metal Conduit (IMC) is prohibited 8) The minimum conduit size shall be ¾ " or equivalent in metric size to allow spaced supports 9) ½ " conduits for instrumentation wiring are allowed in prefabricated skids, and in non-industrial areas of construction sites 10) Conduit and threaded conduit fittings shall have tapered (NPT) threads in accordance with ANSI/ASME B1.20.1 11) Field-cut conduit threads shall be coated with a zinc-rich protective coating 12) Threads of plugs, junction boxes and other fittings shall be lightly lubricated with a rust preventive grease before assembly, unless it is a certified conduit fitted where grease is not allowed 13) The use of conduit unions with an underground conduit should be avoided. If this is not possible, conduit unions must be protected with heat-shrinkable sleeves or wrap-arounds 14) Low-point drains and breathers are required on all conduits 15) In outdoor installations, conduit bodies and fittings shall have threaded cover openings. A conduit outlet box (e.g., identified as GUAT by manufacturers) shall be installed within 18" of the field device. The cable to the instrument shall be looped one or more times within this fitting; the sizing of the conduit outlet box shall take into account the bending radius of the cable. Note: The new smart transmitters and digital valve controllers have very small connection heads compared to previous models. Therefore, a conduit outlet box is being mandated within 18" of the devices to allow for a spare loop of cable. This can potentially prevent maintenance from having to re-pull the cable if the cable end has been damaged. 16) Channel erector system components (Unistrut or similar) used to support conduits, cable trays, enclosures, lighting fixtures and other electrical equipment shall be made of steel or iron, either hot-dip galvanised (preferably) or zinc electroplated as supplied by the Manufacturer 17) Such channel erector system components (Unistrut or similar) used to support conduits, cable trays, enclosures, lighting fixtures and other electrical equipment in severe corrosive environments shall be as specified for conduits: and in addition, protected by PVC coating or manufactured in stainless steel or fibre glass 18) Process piping shall not be used to support conduits in general. If process piping is used to support conduits with the approval of the Owner, adequate corrosion protection at the interface between the piping and support fittings shall be provided 19) Plant structural members that may be necessitated under special circumstances may be used as supports for conduits and on other electrical equipment but need specific Owner approval. However, attachment hardware (clamps, bolts, nuts, etc.) must comply with the requirements of this section 20) Conduit fill shall not exceed the maximum fill specified in NEC 500, chapter 9 21) The following table indicates the minimum distance in millimetres (inches) between steel conduits and trays:
22) The following table indicates the minimum distance in millimetres (inches) between the outside surfaces of parallel steel conduits:
3.3 Field Installation
3.3.3.3.8 Cable Fastening
1) To prevent stresses on cables in trays / ladders, cables shall be suitably fixed / clamped, especially in vertical trays / ladders. Cables on cable trays / ladders shall be laid and fastened tightly and orderly. For final fastening, self-lock Nylon Coated 316 stainless steel cable ties (150 lbs) shall be used 2) Cables on trays / ladders horizontal runs shall be fastened every 1200 mm. Vertical cable runs shall be fastened every 600 mm 3) Cables on secondary supporting material shall be laid and fastened tightly and orderly. For fastening, self-lock Nylon Coated 316 stainless steel cable ties (150 lbs) shall be used 4) All cable ties used inside enclosures and buildings (i.e., Field Junction Boxes, Marshalling Cabinets, Control rooms, Satellite Instrument House or Field Auxiliary Rooms, Analyser Shelter, Substations) shall be weather resistant nylon cable ties with a 316 stainless steel barb. The cable tie shall have a maximum continuous use a temperature rating of 85ºC or higher. Note: Cable trays with covers shall not be considered as “inside of an enclosure”; therefore, nylon coated 316 stainless steel ties shall be used. 5) In general, cable clamps are used to anchor multi-cables to panel frames or clamping under the cabinet 6) Surface Treatment of Cable Ladder and Accessory Constructions: In general, specially manufactured iron construction parts shall be hot-dipped galvanised in accordance with project requirements. Saw cuts and drill holes shall be touched up as specified in the Surface and Painting Project specification. 3.3.3.3.9 Underground Cable Supporting System
If requirements exist to protect against fire damage, underground routing may be considered for main and branch cables with prior approval of the Company / Client. For home-run cables, direct burial is allowed; however, aboveground cable routing is preferred due to various reasons such as easy execution, easy future accessibility, modification and maintenance, etc. 3.3.3.3.10 Computer False Floor
Instrumentation cables installed beneath raised computer-type floors in Control rooms shall be placed in a ladder, trough or solid bottom cable tray. Cable trays beneath raised floors shall be adequately identified using suitable permanent tag plates. These tag plates shall be installed at each end, at tee connections and at 3 m intervals. The tag plate shall be located so that it is clearly visible. The tag plates shall contain, as a minimum, the noise susceptibility level of the circuits enclosed, source and the destination. 3.3.3.3.11 Cables in Trenches and/or Ducts
1) The minimum depth of burial requirements for underground installations shall be as below: 2) In rocky areas where digging must be minimised, depths shown in Figure 3.11 may result in cables being below the water table or interfere with underground obstructions such as other cables, conduits or piping. Cables may then be installed in one of the following configurations: a) PVC coated rigid steel conduit with a total cover of not less than 300 mm, which shall include a 50 mm thick (minimum) reinforced concrete slab over the conduit b) PVC coated rigid steel conduit with a total cover of not less than 150 mm, which shall include a 100 mm thick (minimum) reinforced concrete slab over the conduit c) A reinforced concrete encased duct bank with 150 mm of total cover, measured from the top of the upper conduit, which shall include a minimum of 100 mm of concrete over the upper conduit. Concrete tiles cannot be used in lieu of the concrete slab in (a) or (b) above. The top layer of the concrete slab or the duct bank shall be mixed with red dye (minimum thickness of red concrete layer: 5 mm). 3) Precast 50 mm thick red concrete tiles, red plastic tiles (12 mm minimum thickness) or PVC coated steel fence fabric shall be placed 300 mm above direct buried cables or direct buried conduits. In addition, a yellow warning tape shall be installed over the tiles or fence fabric. This paragraph does not apply to ground grid conductors and connections to ground grids or grounding electrodes
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4) A distance of at least 200 mm shall be provided between instrument cables and electrical power feeder cables in the case of parallel runs 5) See figures above for distance between different power levels for various installations 6) Underground cables shall be laid in hollow block trenches in paved areas and in direct buried trenches in unpaved areas at a minimum depth of 600 mm
Figure 3.11 Cable segregation in paved and unpaved areas.
3.3 Field Installation
Figure 3.11 (Continued)
7) The cables shall be submerged in “clean” sand, such that the thickness of the sand under the cables is at least 50 mm and on top of the cables has a minimum thickness of 300 mm. This clean sand shall not contain debris or rocks 8) The hollow block trenches in paved areas shall be covered with concrete paving (colour code Green) 9) The direct buried cables shall be protected by means of protection tiles on the clean sand, the trench shall than be backfilled with soil and cable route markers shall indicate the complete route of the trench 10) The track of the cables shall always be marked
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11) Cables shall be laid with sufficient slack (especially at rising points) to prevent stress, in particular where trenches are made in soft soil 12) If there is a risk of damage from heavy traffic loads, the crossing shall be provided with a concrete reinforcement or cable ducting 13) Inside the pipes there shall be minimal 50% spare space after cable installation 14) When the cables have been laid in the crossing, the conduit pipes (including spare) shall be closed with easily detachable material 15) If conduits are installed in more than one layer for other purposes as well, cables shall be installed in the lowest layers 16) Spare capacity sleeves shall be provided with a pull wire and covered with removable caps 17) All sleeves shall be laid such that the subsidence with a pull wire shall not damage the cables by the pipe ends 18) Pipe ends shall be provided with pipe-sealing rosettes 19) In the case of paving, spare capacity pipes shall be considered with a pull wire and covered with removable caps to allow paving to be carried out in opportune time 20) Where cables enter the building, maximum possible slack shall be left in the cables before termination, to allow for soil movements directly outside of the building 21) Open pipe trenches shall be crossed with bridges over the pipe trench. Bridges shall either be adequately supported ladders or reinforced concrete and backfilled with a sand cement mixture 22) In case cables run from trench to boxes on columns through concrete paving or floors, suitable HDPE sleeves (approximately Ø I.D. 110 mm, depending on cable bending radius) shall be used 23) For each dedicated instrument cable segregation group, separate sleeves shall be used 24) Filling of sleeves shall be a maximum of 40% of the available square area 25) Sleeves shall be provided with a pull wire and covered with removable caps to avoid congestion during construction. 3.3.3.3.12 Duct Bank System Installation
1) For road crossings and for the long main cable run where vehicle traffic expected such as under the pipe rack, pipe rack to local and remote buildings, fenced-road area, etc., a Duct Bank System shall be used 2) The Duct Bank shall be PVC or non-metallic pipes encased in concrete of at least 75 mm thickness 3) The top of the concrete encasement shall be at least 600 mm below grade where the duct-banks cross the road 4) Multi-cables may be installed in one pipe provided that the current carrying capacity of the cable remains within the allowable limit 5) A concrete duct bank is usually planned on site by Engineering and so the following specifications are made part of this Handbook as a guidance: ● The minimum depth shall be 600 mm ● Duct banks shall consist of PVC conduit, encased in concrete. PVC duct shall be minimum 2" and maximum 6". PVC conduit (duct) shall be Type EB-35 or DB-120 (minimum modulus of elasticity 500,000 psi) per NEMA TC 6 and 8 or Type EPC-40-PVC per NEMA TC. (Ducts and conduits normally follow American standards and sizes are denominated usually in Inches – and that convention is followed in the Handbook.) 6) There shall be a minimum of 75 mm of concrete from the outside surface of the duct bank to any conduit or reinforcing steel 7) Fabricated spacers shall be used at intervals not exceeding 2.4 m 8) The spacers shall provide a minimum conduit separation of 50 mm for 2" conduits and larger 9) Conduit runs within the duct bank shall be made continuous, of PVC solvent cement with PVC couplings 10) Bell end fittings or protective bushings shall be provided on each duct where it terminates 11) The top layer (5 mm minimum thickness) of the concrete shall be mixed with red dye or red-colour paint on top of the duct bank 12) Duct banks shall have 20% spare ducts (minimum one), unless otherwise specified 13) The duct shall be marked at intervals of 1.5 m (5 ft) or less with the following: ● Manufacturer’s name ● Nominal trade size ● “NEMA TC6/TC8” ● Type: “EB-35” or “DB-120”.
3.3 Field Installation
14) Material Spec check ● The duct shall be mandrel tested in both directions before and after concrete placement. Nominal 4 " inside diameter conduits must pass a 3⅝" diameter × 12" length mandrel ● Burial depth of duct bank may be reduced where the duct bank is installed free from the heavy loads. 3.3.3.3.13 Cable Entry Sealing
1) Where cables have to be led through exterior walls or partitions with a fire blocking, water blocking or sealing function, properly qualified cable transits shall be installed 2) After installation, cable transits shall remain well accessible with respect to mounting, inspection and testing for leaks 3) The spare space to be kept in the cable transits shall correspond to the spare space on the cable ladders, but shall be such that after “Approved for Construction” documents, 30% additional cables can be led through 4) All cable and cabinet entries through floors shall be fully sealed after completion of cable installation for rodent protection 3.3.3.3.14 Cable Termination
All cables and wires shall be routed and terminated in accordance with approved wiring diagram and loop diagrams. 3.3.3.3.15 Noise and Signal Interference Reduction
1) Noise a) Signal wiring shall be installed in a manner that will minimise unwanted and unnecessary distortion of the signal. Unwanted voltages are imposed on an electric signal transmission system by inductive, capacitive or direct coupling with other circuits by leakage current paths, or ground current loops. In addition, utilising common return leads for more than one circuit shall be avoided to minimise noise b) Twisting and shielding of instrumentation wiring shall also be used, as detailed below, to minimise the noise impact on instrumentation signals. Twisted pairs / triads shall be used to reduce electromagnetic noise. 2) Shielding a) Shielded cables shall be used to reduce electrostatic noise. The shield shall be grounded at one point only, typically at the marshalling cabinet in the Control room or at home run cables’ first interface building. Exception: Shield for grounded thermocouple shall be grounded in the field, at the thermocouple end b) Cable shields must have a single, continuous path to ground. Special grounding terminals in intimate contact with the DIN Rail, jumper bars or preformed jumper combinations designed for the selected terminal blocks shall be used to consolidate shield drain wires for connection to ground. Ground loops and floating shields shall be avoided. Shield drain wires shall not be daisy-chained to the ground connection but star-connected c) For twisted shielded single pair / triad cables, the outer jacket shall be left intact up to the point-of-termination (approximately 3" to 4 " from terminal blocks) d) The shield drain wire shall be insulated from jacket end to terminal. A heat shrink tubing shall be applied over the jacket end (typically 1 ") e) For individually shielded twisted multi-pair / triad cables, each pair / triad shall be heat shrink sleeved and insulated from the cable-jacket-end up to the point-of-termination to keep the foil shielding intact and free from accidental grounds. The shield drain wire shall be insulated from foil end to terminal. Adequate, heat shrink tubing (typically 2") shall be applied over the jacket end f) In installations where there is a transition from multi-pair or multi-triad cables to individual pairs / triads for field device connection in a junction box, the respective shield drain wires shall be joined via a terminal strip and shall not make electrical contact with the junction box or any other circuit. Using push-on type connectors or sandwiched shield bars for shield drain wire connection is not acceptable g) The shield drain wire on the ungrounded end of the cable shall be cut and insulated with a heat shrink sleeve to prevent unintentional grounding h) Except for coaxial cables, instrument cable shields shall never be used or considered as signal conductors.
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3.3.3.3.16 Cable Glands Installation
1) Cable glands are selected such that they suit the selected instrument cable and are suitable for the hazardous area classification concerned. They differ in the usage for say Ex e vs. Ex d, etc. So care and attention must be paid to installation of cable glands and its appropriateness to the enclosures, as Plant Safety Certifications are involved 2) Certified flameproof (Type “d”) cable glands using a compound barrier seal shall be used on all instruments and enclosures located in hazardous areas requiring sealing per the NEC. Where sealing is not required by the NEC, Certified Flameproof (Type d), cable glands shall also be used on all instruments and enclosures, including those located in nonhazardous areas. For example: a) For Ex “d” instruments (if the cable enters directly into an Ex d enclosure): Example, CMP Make, Model / TypePX2KREX or equal is used. This is a cable gland with a barrier compound. The barrier compound shall be filled after successful continuity test of the cable, prior to loop test b) For all other classifications (Ex i, Ex e, etc., and for Ex d instruments if the cable is connected to a non-Ex d compartment): Example, CMP Make, Model / Type- TE1FU or equal is used. Interchanging would void Safety certifications and endanger the plant. 3) Shrouds are required on all cable glands. Earth tags shall also be provided on cable glands. 3.3.3.3.17 Connections at Field Instruments
1) All connections at the field instrument shall be made on screw type terminal blocks. Wire nuts and spring type terminals shall not be used. Instruments with integral terminal blocks shall be connected directly to the field cable 2) If the instrument is fitted with factory sealed fly-leads then they shall be connected to a screw type terminal block installed in a GUA conduit fitting 3) All armoured cables shall be terminated using cable glands 4) Both ends of any armoured cable shall be terminated using glands 5) The outer jacket of shielded twisted single pair / triad cables shall be left intact up to the point of termination. Drain wires and Mylar shields on shielded cables shall be cut and insulated with a heat shrink sleeve at the field instrument unless otherwise specified by the instrument manufacturer. 6) For armoured cables, the “outer jacket”, in this case, it is the jacket covering the pair or triad, not the jacket covering the armour. 3.3.3.3.18 Connections at Field Junction Boxes
1) General a) All instrument wiring shall be routed only to field junction boxes b) The terminals shall be mounted on vertical DIN rails (i.e., horizontal DIN rails are not allowed) c) The DIN rail shall only be mounted on the inside panel (back-pan) of the junction box d) 20% unused DIN rail length shall be provided in field junction boxes. 2) Conduit Installations for Unarmoured cable a) Conduit and cable entries to field junction boxes shall be preferably through the bottom b) Top entry is allowable inside building / enclosures, provided that a drain seal is installed on the conduit within 18" of the enclosure. Side entry (within 6" of the bottom) shall be permitted only when space limitations dictate c) The number of conduit entries shall be kept to a minimum d) All unused entry ports shall be fitted with approved plugs e) Gasket materials shall be oil resistant f) All connections and entries shall comply with the electrical area classification g) Low point conduit drains and high point breather (with flame arrester in hazardous areas, as stated earlier) shall be provided as needed h) Conduit entries shall be through gasketed hubs, except in explosion-proof installations where the connection shall be through threaded connections i) Twisted, multi-pair / triad cables shall be cut to the appropriate length to minimise looping and flexing of the cable within the junction box j) For twisted shielded single pair / triad cables, the outer jacket shall be left intact up to the point-of-termination (approximately 3" to 4" from terminal blocks). The shield drain wire shall be insulated from jacket end to terminal k) Conduit Sealing for Individually Shielded Twisted Pair / Triad Cable
3.3 Field Installation
When individually shielded twisted pair cables pass through a conduit seal, they shall be treated as a single conductor and shall be sealed with the outer jacket intact. In addition, the cable end within the enclosure shall be sealed by an approved means. 3) Cable Gland installations for Armoured cable a) Top entry of armoured cable into the junction box is generally not preferred in outdoor environments, even if through weather protected cable glands b) All unused entry ports shall be fitted with approved plugs c) In severe corrosive environments, cable glands shall be protected against corrosion, either by a heat shrink sleeve, anti-corrosion tape or PVC shroud d) Gasket materials shall be oil resistant e) All connections and entries shall comply with the electrical area classification f) Twisted, multi-pair / triad cables shall be cut to the appropriate length to minimise looping and flexing of the cable within the junction box g) For twisted shielded single pair / triad cables, the outer jacket shall be left intact up to the point-of-termination (approximately 3" to 4" from terminal blocks). The shield drain wire shall be insulated from jacket end to terminal h) Approximately 1" of heat shrink tubing shall be applied over the jacket end. For armoured cables, the “outer jacket” is the jacket covering the pair or triad, not the jacket covering the armour i) For individually shielded twisted multi-pair / triad cables, each pair / triad shall be heat shrink sleeve insulated from the cable-jacket-end up to the point-of-termination to keep the foil shielding intact and free from accidental grounds. The shield drain wire shall be insulated from foil end to terminal. Approximately 2" of heat shrink tubing shall be applied over the jacket end. 3.3.3.3.19 Termination
a) Methods 1) The termination shall be channel (rail) mounted, strip-type terminal blocks, with tubular box clamp connector and compression bar or yoke, as detailed below 2) When screw-type terminals are provided on field instruments or other electrical devices, solderless crimp / compression connectors shall be used for connecting stranded copper conductors. Screw-type terminals are defined as those in which the termination method involves the direct compression of the conductor by the underside of the screw head, and which do not contain the conductor within a clamp or yoke 3) Insulated ring lugs or locking fork connectors, specifically designed to hold the connector on the terminal in the event of loosening of the terminal screw, shall be used on all such connections 4) Exposed electrical connections at signal lamps and pushbuttons shall be completely shrouded by removable, insulating covers. b) Terminal Blocks The details of terminal blocks to be used is included under purchase specification of terminal blocks in Section 4.4 of Chapter 4. Installation details are included here: 1) Wires terminated on these terminal blocks shall not have the bare ends coated with or dipped in solder (“tinned”). However, termination of wiring that has individual strands of the copper conductor tinned during manufacture (typical of shield drain wires or for corrosion protection) is acceptable. Direct termination of the bare wire end is acceptable. No more than two bare wire ends shall be connected to each side of a single terminal block 2) The use of crimp-on ferrules for this type of termination shall follow manufacturer’s guidelines. Ferrules shall be provided with plastic insulating collars. Two-wire ferrules are acceptable. However, the use of ferrules to daisy chain is not acceptable. Only one ferrule shall be connected to each side of a single terminal block. c) Terminal Strip Assemblies 1) Each terminal strip shall be labelled above or below with the terminal strip number, as shown on wiring diagrams 2) Terminals for similar (AC or DC) current service shall be grouped together and physically separated from terminals for different service by means of dividers, separate mounting rails or separate enclosures 3) Terminals for 120 VDC and 120 VAC power for field contacts shall be segregated from other systems 4) Terminal strips for ESD wiring shall be completely separate from all other wiring including power, control and instrumentation.
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3.3.3.3.20 Identification
1) Wire Tagging: a) All wiring shall be tagged at each end. Each wire tag shall have two labels. The first label (closest to the end of the wire) shall identify the terminal number to which the wire is physically connected. The other label shall be the terminal number of the connection of the opposite end of the wire b) The source and destination information is to be imprinted on one heat shrink sleeve and not on two separate wire tags (one containing the source information and the other containing the destination information) c) Where wires terminate on instrument or device terminals, the instrument tag number and terminal designation, (+) or (-), shall be used in lieu of terminal strip identification d) Wire tag information shall be permanently marked in block alphanumeric or typed on tubular, heat-shrinkable, slip-on sleeves. Wrap-around, Snap-on or Self-adhesive wire markers shall not be used. Handwritten wire tags are not acceptable. Exceptions: 1) Alternate wire tagging schemes, which conform to established local practice, may be used for extensions to existing facilities with the prior approval of the Owner 2) Plastic sleeves that are specifically designed to fit on a specific wire gauge and come with pre-printed alpha/numeric inserts (such as the Grafoplast Trasp System) may be used for wire tags with prior approval of the Owner e) A clear heat shrink sleeve shall be installed over the wire tag for all instruments that use rust preventive grease on their threaded wiring access cover f) Spare Pairs / Triads in Multi-Pair / Multi-Triad cables shall be labelled “Spare” in addition to the destination and source terminal numbers. The Spare designation shall be on a separate wire tag installed on the twisted pair and not part of the source/destination tag. Note: The use of “Spare” designation usually printed is discouraged on each source / destination wire tag because this would require new tags to be made when the conductors are utilised. 2) Cable Tagging a) The cable tag as indicated in the cable list shall be used for cable identification at both ends of the cable b) All field single cabling shall be coded with the applicable instrument tag number at both ends close to the instrument and to the junction box c) Aboveground cables shall be identified by means of weather- and UV-resistant cable marker rings or SS 316 plate stamped with their cable number Cable markers are typically stainless steel 3.5" × 0.75" marker plate with two holes on each side for use of cable ties d) Underground cables shall be identified with their cable number at each point where they enter or leave the surface as well as at duct-banks, road crossings, etc. Underground cables and tubing shall be marked at intervals of approximately 15 m by means of stainless steel 316 engraved / embossed strips e) Cables entering or leaving wall penetrations shall be marked at both sides f) Cable tags shall be provided at both inside and outside the gland plate of junction boxes and instrument panels, marshalling cabinets, system cabinets, server cabinets, etc. g) All cables shall be tagged, at each end, with a cable-tag h) Home-run cables shall be tagged with the assigned Instrumentation Cable (IC) number. Generally, the cable tagging philosophy for cables routed from junction boxes to field instruments is pre-defined by the EPC in consultation with facility Owner and part of construction drawings. Note: Some facilities prefer to tag the instrument cables with the instrument cable number (e.g., IC-1249), while other facilities prefer to tag the cables with the instrument tag number (e.g., TT-1249). i) Cable tags outside junction boxes and marshalling cabinets shall be 316 SS with permanently marked alphanumeric characters, i.e., raised or stamped characters
3.3 Field Installation
j) The cable tags shall be securely attached to the cable with stainless steel cable ties k) Where cable tags are required inside junction boxes or marshalling cabinets (i.e., cables extended in conduits), weather resistant, high-quality plastic cable tags secured using cable ties may be used. 3) Terminal Reference a) Each row of terminals shall be uniquely identified alpha-numerically, e.g., TS-101, TS-102, etc. b) The terminals in each row shall be sequentially numbered starting at number one. The following set of diagrams in Figure 3.12 are examples of various cable crossings installation drawings prepared for a particular project:
Figure 3.12 Cable crossings – typical.
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3.3.3.3.21 Cable Supporting – Installation Detail
1) Cable supporting considers cable tray, ladder racks, closed trunking and dedicated steel profiles, and shall be divided in the following groups: a) Main cable supporting, meaning cable tray / ladder racks with a minimum size of 300 mm b) Sub-cable supporting, meaning cable tray / ladder racks smaller than 300 mm c) Secondary cable supports can use dedicated heavy gauge steel profiles / conduits / “Colson” strips, etc. 2) Default cable tray size selection usually specified in design are usually 300 / 450 / 600 mm, with a minimum height of 100 mm. The 600 / 900 mm tray may need heavy stiffening and higher height if used and so preferably it is made as a cable ladder 3) Cable supporting installations shall be adequately supported with a minimum of one support per three 3 m installation. Next to every branch in the cable supporting system, a support shall be installed within 1 m. Wherever possible, the supports shall be arranged such that cables can be laid sideways into the tray / trunking instead of pulling them through consecutive holes 4) Free space over the tray, ladder racks and trunking shall be a minimum 200 mm to ensure cables can be easily laid down during construction 5) Cable supporting installation shall be joined by bolts and nuts. Bolts shall be installed with the round head internally and the nut externally. All joints shall be smooth finished, so that no damage to cabling and / or tubing shall occur 6) The cable supporting installation shall not obstruct traffic, hoisting installations or interfere with accessibility or removal of process equipment such as pumps, motors and heat exchanger bundles, etc. 7) Sufficient expansion possibilities on cable supporting installations shall be provided for: a) straight runs longer than 25 m b) at dilatation joints in buildings or structures c) runs in areas with big fluctuations in temperatures. 8) Redundant cables shall be routed via different paths in a diverse route so that single point failure of both redundant cables shall be avoided. Fibre Optic cables routing through electrical trench are allowed 9) Cables and cable trays / ladders shall be routed away from hot environments and places with potential fire risks such as hydrocarbon process pumps, exchanger heads, burner fronts of furnaces and boilers 10) Those parts of the cable supporting which shall be installed in places where they are liable to be damaged by plant fires shall be provided with fire proofing, as specified in applicable project specifications. When the cables are fire proofed, i.e., fire retardant and fire-resistant types, fire proofing of cable ways are not required 11) Cable supporting shall be located away from where they are subject to mechanical damage, spilt liquids, escaping vapours and corrosive gases. Where cable trays are liable to damage by traffic, they shall be protected by freestanding and sturdy mechanical structures 12) Cable ladders / trays shall only be mounted sideways and only horizontally with Manufacturer / Client approval 13) Rung distance of cable ladder shall not be more than 300 mm. The length of the individual cable ladders shall be so that mounting or dismantling can be done with easily handled sections 14) Looping of cables shall be avoided. Only in cases of ladder / tray expansion, is looping of cables required 15) Single overhead cable runs may be attached to steel work, secondary cable supporting systems like Colson strips, strut channels, etc., if they are not to be subjected to mechanical damage 16) Fasteners such as bolts, nuts and washers shall be at least of corrosion-resistant steel as a minimum. In any case, they shall be resistant to the effects of the environment in which they are to be used and adequate for the load to be imposed upon them without undue stress or sagging 17) Fasteners shall be of the same material as supporting, to avoid corrosion due to electrolysis 18) Bends in cable supporting systems shall be based on the minimum bending radius of the thickest cable as advised by the Manufacturer 19) Cable supporting shall be of a rigid design and self-supporting between holding brackets without excessive deformation after the cables are installed. Cable supporting shall at least be in accordance with Manufacturer specification based on maximum load 20) Cable supporting systems shall be designed and installed to ensure electrical continuity throughout the run and such that water cannot collect or remain in any part of the system 21) Bonding wires with bolted connections at coupling points shall be used for electrical continuity. Coupling plates of trays are assumed to provide proper bonding for the tray systems
3.3 Field Installation
22) Cable supporting systems for secondary cable routing shall be adequately supported. Each piece shall have a minimum of two supports, and shall only be installed horizontally or vertically and parallel to the plant coordinates 23) Where cables are required to be installed through or across the edges of tray or other metal work, the edge of the lips shall be smoothed, protected from the environment and lined with a protective sleeve to avoid cable damage 24) All cable trays / ladders shall be closed with removable aluminium covers to counter act following situations: ● To protect cables exposed to solar radiation ● ●
For protection against possible leakage or liquid For protection against mechanical damage during maintenance, e.g., on locations for equipment.
25) Turnovers ● Minimum of two straps / bands or equivalent shall be installed per single piece of cable supporting cover ●
Secondary cable supports shall be manufactured from good-quality heavy gauge steel, galvanised, preferably. “L”- or “U”-shaped profiles shall be used. They shall be protected from the environment in accordance with the applicable project documentation.
26) All the supports and accessories used for the cable tray system in a corrosive environment shall be either PVC coated or rated / certified for suitable to install in such an environment. Cable trays / ladder design, fabrication and installation mostly follow some standards that provide support design for reference extensively and may be referred to for any design. For cable tray / ladder specifications for procurement, refer to Chapter 4.
Figure 3.13 Cable Ladder Installation (CSA / NEMA VE-1 & 2).
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Figure 3.13 (Continued)
Figure 3.14 Cable Tray Installation.
3.3.3.3.22 Cable Entry Sealing and Multi-Cable Transits (MCT) Installation
Multi-Cable Transits (MCT) are frames with inserts and entry seals that provide entry of cables (or even conduits / pipes) into Control rooms providing a certified safe sealed entry. For specifications for procurement, refer to Chapter 4. Typical installation guidelines provided by Manufacturers / Vendors: a) Earthing of armoured cables at the MCT end, if opted for, require special for studs on frames b) General Installation practices are as follows: 1) Generally, power cables are laid at the lowest level, followed by a stay plate isolation, then followed by multi-signal cables and so on, until single pair cables in various layers to the top 2) Larger cables at the bottom would be a preferred option. However, all large-size cables can also be grouped at one portion of the MCT and all other sizes in the balance portion 3) All pairs shall be identified with Heat-Shrink White Polyolefin markers 4) In case of a large number of power cables, it may be advisable to provide a separate MCT for power cables with necessary separation from signal cables. Only L.V. Instrument power cables to Field from the Control room are routed and the decision to provide MCTs for electrical cables is to be taken by the individual plant or due to specific project location requirements:
3.3 Field Installation
Figure 3.15 MCT Installation.
i) Electrical departments do not use MCT but use duct banks ii) IS and 24 DCV cables are segregated, as are AC wetted signal cables such as switches. 5) Some Manufacturers offer peeling type blocks, so that there is no worry about exact cable diameters, etc., in the design 6) Maximum height of the Frame shall not exceed 600 mm. c) Fire resistant, blast pressure proof, gas tight, water tight, EM screening, etc. are specified as part of specifications. The specifications include the following as a minimum: ● Type ● Transit for use of Control room / onshore or marine / offshore use ● Codes or standards, if applicable ● Material ● Quantity per size ● Cable sizes in each quantity ● Cable arrangement in each ● Fixing arrangement on wall or structure: metal, civil, etc. ● Corrosion resistance ● Body material – mild steel – most common, available in SS and other materials including FRP and aluminium ● Material of other components ● Special tools and accessories – mostly required for each type including sealant. ● Dummy blocks for unfilled areas ● Sealing required for water / gas / fire / explosion, etc., with certification requirement ● Normal Control room locations away from plant may require to be only water / gas tight ● For blast proof walls, explosion proof (blast resistant) MCTs will be required ● Protection against fire propagation, if required, must be specified ● Specific fire resistance to Insurance regulatory code or blast resistance to code or company specs. d) Installations are generally inspected by the Fire Officer. For specification of MCTs procurement engineering specifications, refer to Chapter 4.
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3.3.3.3.23 Cable End-to-End Installation
As stated before, all cables and wires shall be routed and terminated in accordance with approved wiring diagram and loop diagrams. Installation drawings shown in Figure 3.16 may be considered as an example showing the typical method of cable routing, wiring and termination.
Figure 3.16 Cable from Tray to Inst / JB.
3.3 Field Installation
3.3.3.3.24 FF Cabling and Wiring – Special Note
Field Foundation Bus (FFbus) cabling differs from conventional cabling in some respects. The earthing and grounding scheme is more complex and rigorous. FF wire is stranded like any signal cable but, as FFbus is a frequency-based system, it is extremely susceptible to Signal Interferences. It has several field termination boards for Spur and Trunk and for accessories like power isolations, barriers / couplers, surge protectors, terminators, etc., that are also polarity sensitive. The colour coding is completely different from conventional cabling (as already stated elsewhere in this Handbook), with different terminologies such as Spur and Trunk, etc. LED status at every field unit is also a feature not common with conventional cabling.
Figure 3.17 FF cabling – Field.
Figure 3.18 FF cabling – Control room.
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A table (sample shown in Table 3.16) usually accompanies the typical drawing issued for construction (block diagram sample above). Table 3.16 Field Trunk cabling and marshalling at CR.
3.3.3.3.25 Fibre Optic Network Cabling – Special Note
The guiding standard used by most engineers is NEIS – NECA/FOA 301–2016 or latest edition – Standard for Installing and Testing Fibre Optics, that provides a good installation perspective and forms for checks, although not mandatory (but it does list mandatory applicable standards). It provides a good standard for installations where the Fibre Optic (FO) cabling extends between buildings, especially for FO cabling used for computer networks (LANs), closed circuit TV (video), voice links (telephone, intercom, audio), Building Management Systems, security or fire alarm systems, or any other communications link. Generally, of the two types of broadly classified FO known as Structured or Centralised, for Instrumentation, a Centralised architecture, Optical Local Area Network (OLAN) is used. Its passive distribution can reach up to 32 devices that is mostly sufficient, except perhaps for BMS for large integrated control and admin buildings, where a structured or combination approach is used. Usually, multi-mode 125 micron fibre is adequate. When exceptional bandwidth is required, single mode fibres may be used.
Figure 3.19 FO network cabling – Distributed vs. Structured (NECA / FOA 301 – 2004 & ANSI / TIA –568).
1) Typical tag for FO cable will have the following technical details: ● Drum No. and Length ● ● ●
Fibre ID Attenuation Minimum Output Power
Wavelength. These must be verified against the Purchase Order. 2) Technical checks before Installation ● Visual Check ● Continuity / Attenuation 3) Installation Safety ●
3.3 Field Installation
General principles and safety in FO installation involve many of the same issues as installing any other cable. However, the following must be followed, in addition: a) Safety in FO installations specifically includes avoiding exposure to light radiation carried in the fibre; disposal of fibre scraps produced in cable handling and termination; and safe handling of hazardous chemicals used in termination, splicing or cleaning according to job and manufacturers’ specifications and company or client site-specific standards. b) Fusion splicers create an electric arc. Flammable vapours and / or liquids present can ignite and so precautions need to be taken accordingly. They are not to be used in confined spaces as defined by OSHA c) When using an optical tracer or continuity checker, looking at the fibre from an angle of at least 300 mm (12") away from the eye is recommended, even if only visible light is present d) Optical fibres are sensitive to dust and dirt and require highest standards of cleanliness during installation. Protective dust caps on connectors, mating adapters, patch panels, or test and network equipment are standard. Only special cleaning tools made for cleaning optical fibre connectors (lint-free wipes) are to be used with pure reagent grade isopropyl alcohol to clean connectors. Compressed air may not be totally oil free and so squeeze bulbs are preferred to blow out dust e) Handling large reels of FO cable requires special slings and care for movement f) Reels, regardless of size or length, must have both ends of the cable available for the testing. A fibre tracer or visual fault locator and bare fibre adapters are used for continuity testing. Cables suspected of having been damaged in handling may require Optical Time Domain Reflectometer (OTDR) testing of a sampling of fibres to verify the condition of the cable before Installation. Generally, Fibre Optic (FO) cables are not to be pulled in a conduit or duct containing other cables g) Fire stops and fire separations are required as per standards. Even though it is dielectric and may be laid with power cables, some separations are preferred h) Although most FO cables are not conductive, any metallic hardware used in FO cabling systems (i.e., wall-mounted termination boxes, racks and patch panels) must be grounded i) A common initial error is attempting to connect fibres with different core diameters. Even if connectors are compatible, it should be avoided as different core diameters could result in loss of transmission. 4) Installation Guidelines a) Outdoor FO cable may be directly buried, installed underground by being pulled or blown into a conduit or inner duct, or installed aerially between poles. Indoor cables can be installed in raceways, cable trays, placed in hangers, pulled into a conduit or inner duct or blown through special ducts with compressed gas. The installation process will depend on the nature of the installation and the type of cable being used but generally installation is no different from other electrical cables, especially on sticking to manufacturer’s instructions on pull torsion, bend radius, etc. b) All splices are to be within an enclosure and need to be over-ground for easy maintenance check. Splices are permanent joints and connectors are temporary joints. Invariably, patch panels moving from multi-fibre pair to individual fibre pair or connections to electronics through connectors at the electronic end are spliced at the patch panel using Laser Fusion splicing techniques, although mechanical splicing is sometimes undertaken for temporary checks c) Fibre Optic connectors are available with a variety of colour codings (e.g., SC, ST, LC, MTP) and variations, etc., and here it is required to follow OEM instructions d) In fibre networks, separate fibres are typically used for transmission in each direction (Duplex), therefore it is necessary to identify the fibre connected to the transmitter and receiver at each end, even if ends are keyed for connections. OTDR test is required to check splicing performance end to end, including intermediates and connectors e) Generally testing is done in one or more ways or a combination of ways (see Figure 3.20): 1) Continuity testing to determine that the fibre routing and / or polarisation is correct (and documented properly) 2) End-to-end insertion loss to be checked using an Optical Loss Test Set (OLTS) power meter and source. Test multimode cables by using TIA-526–14, and single mode cables using TIA-526–7, as the NEC standard. f) OTDR testing may be used to verify cable installation, splice performance and troubleshooting problems and also Loss-budget guarantees initially signed-off in contracts. The OTDR “trace” contains data on the length of the fibre, loss in fibre segments, connectors, splices and loss caused by stress during installation and therefore is preferably test before network Commissioning in Refineries with long transmission lengths. However, it needs a specially trained person to perform and record the test results while using special equipment (as shown in Figure 3.21). g) Typical Form for checkout and commissioning of FO cables (shown in Figure 3.22)
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Figure 3.20 Fibre Optic Link and Testing.
Figure 3.21 FO – TDR testing (FS community). Note: TDR photo is for representational understanding.
3.3.4 Field Instrumentation Earthing Installation The material detail of earthing wires and grounding rods are provided in Chapter 4. 3.3.4.1 Grounding and Earthing Plan
Electrical systems must be connected to ground for the protection of personnel and equipment from fault currents (AC safety ground) and to minimise electrical interference in signal transmission circuits (Instrument DC and Shield ground). 1) Two grounding systems are required for instrumentation systems: a) Safety Ground for personnel safety. b) Instrumentation DC and Shield Ground. 2) Both safety ground and instrumentation DC level rated signals and shield ground installation must conform to NEC Article 250, IEEE 142, IEEE 1100 and meet the requirements of ANSI/NFPA 70 (NEC) and ANSI C2
3.3 Field Installation
Figure 3.22 FO test check form.
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3) In this section, the field grounding installation is detailed. The specifics of Control room grounding and its overall integration with the field is discussed under Control room works 4) Instruments Operating at Greater than 50 volts: The enclosures for instrument devices operating at 240/120 VAC (nominal) or 110/125 (nominal) VDC shall be grounded as per electrical discipline standard requirements 5) This section generally deals with Instruments Operating at less than 50 VDC, unless otherwise specified, using one of the following options: a) Connecting the enclosure directly to the grid using 25 mm2 ground wire b) Connecting the enclosure to a grounded instrument stand or other supporting structure, provided that the instrument device is properly fastened and the mounting clamp is mechanically and electrically in intimate contact with the stand. c) Using the cable armour (when armoured cable is used) provided that the following criteria are met: i) The armour construction is suitable as a grounding path per NEC standards ii) The cable glands, on each end of the armoured cable, shall be designed to bond the armour to the gland (i.e., listed as suitable for grounding) iii) The armoured cable runs in one continuous length from a properly grounded junction box to the device being grounded, i.e., no splices are permitted iv) The (armour of the) armoured cable is not in direct contact with the soil for any portion of the run. d) Using the conduit as a ground conductor, provided that the conduit system is continuous and properly grounded. A bonding jumper shall be used across any flexible conduit at the instrument end. All conduit fittings shall be listed as suitable for grounding. e) Aluminium cable trays containing only circuits operated at, or below, 50 V to ground may be used as equipment grounding conductors, provided that NEC requirements for such use are met. On other aluminium cable trays, a common equipment grounding conductor external to the cables in the tray may be used under the following conditions: i) This common conductor shall be sized in accordance with NEC table 250–122 for the largest power conductor in the tray, with a minimum size of 25 mm2 (#4 AWG) ii) Connections shall be made between this common grounding conductor and other grounding conductors for intersecting or branch trays, and to extend the equipment grounding conductor beyond the tray iii) This common conductor (or the largest individual grounding conductor, if more than one is installed) shall be bonded to each section of the cable tray system with a connector approved for a copper to aluminium connection. 6) Metallic conduit shall be grounded at both end points by bonding to a grounding conductor, a grounded metal enclosure, or to a grounded metal cable tray. This may be accomplished by any one of the following methods: ● with approved grounding clamps and conductors connected externally to the conduit ●
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by bonding to a grounded enclosure using integral threaded bushings or using a conduit hub (which is approved for grounding purposes)
bonding to a grounding conductor using an approved grounding bushing (Note that grounding with lock nuts is not acceptable) where non-PVC coated rigid conduit is used to protect cable entering or exiting a grounded metal cable tray, by bonding with a conduit clamp to the cable tray a grounding bushing must be used with PVC coated conduit.
3.3.4.2 Safety Ground Installation
a) All exposed non-current-carrying metallic parts that could become energised with hazardous potentials must be reliably connected to the equipment grounding circuits. This assures that hazardous potential differences do not exist between individual instrument cases or between an instrument case and ground. Therefore, all metal equipment and enclosures within a panel or series of panels (i.e., instrument cases, hinged doors, racks, etc.) shall be bonded with bonding jumpers and connected to a safety ground bus with a minimum copper wire size of (4 mm2) b) Two copper conductors, 25 mm2 minimum, shall be connected from the safety ground bus to a single tie point on the safety ground grid in a closed loop configuration. Safety ground connections must be made such that when a casegrounded instrument is removed, the integrity of the rest of the safety ground system is maintained c) In the field, instrument stands shall be connected to the safety earth by means of earthing cable. Instruments mounted on stands shall be earthed to the stand with earthing cable
3.3 Field Installation
d) All the cable ladders / trays shall be connected to plant safety earth at every 20 m distance minimum e) Earth cable colour code and size shall be as indicated in the typical drawings below, unless otherwise specified in design documents (some variations are seen from region to region) f) Earth connection cables for clean earth shall be executed in the colour code Green g) All metal frames, cable tray / ladder, box racks, junction boxes, local panels, etc., shall be connected to the safety earth by earthing cable (Yellow / Green), size to be as indicated in the applicable project documentation h) All earthing points / connections shall be fitted with locking devices. Crimp / compression type lugs shall be used for bolted connections i) Crimping lugs shall be insulated bootless ones for normal terminations instead of pin type j) Metallic cable trays shall be bonded to the local ground grid or ground electrode at both end points, ensuring that bonding continuity is met throughout all the racks in the system. 3.3.4.3 Instrument DC and Shield Ground
a) In field installations, the purpose is to tie the instrument DC and shield ground bus bar to a common point in the Control room or home-run cable termination auxiliary room/s and to reduce the effect of electrical interference upon the signal being transmitted b) A DC and shield ground bus bar is provided within each cabinet in the Control room for consolidating instrument signal commons and cable shield drain wires. This ground bus is isolated from the safety ground system and from the body of the cabinet, except at the plant reference point c) The details of an integrated earthing plan are provided under Section 3.6, on Control room works. Special Considerations: Some equipment (data highways, computers, distributed control systems, etc.), cables and field installations, etc., may require special provisions for grounding. Manufacturers’ recommendations should be carefully evaluated at all times. 3.3.4.4 Safety Ground Conductor Connections
The details of grounding conductors are provided under Section 3.3 on Control room works, as they are installed outside Control rooms or auxiliary rooms on onshore projects. a) Below-ground connections to grounding grids and ground rods or between conductors and / or grounding rods shall be made using one of the following methods: 1) By thermite welding or brazing 2) By approved compression grounding connectors 3) For connections at ground test stations only where it is necessary to disconnect ground conductors for tests, approved mechanical connectors may be used. b) Aboveground grounding system connections shall be made by one of the following: 1) In accordance with the NEC 2) By thermite welding or brazing 3) To structural steel using compression type connectors bolted to bare steel, by thermite welding or by other approved means c) Grounding conductors, which do not accompany associated power conductors in the same conduit, shall not be installed in a metallic conduit except where PVC conduit is not suitable and it is necessary to protect the conductor from mechanical damage d) Grounding conductors installed in metallic conduits or sleeves that do not accompany associated power conductors shall be bonded to both ends of the metallic conduit e) Grounding conductors extending through concrete or asphalt shall be run in a PVC conduit (preferred) or PVC coated rigid steel conduit. Grounding conductors in a steel conduit shall be bonded f) Underground ground conductors shall be insulated when within 3 m of a buried metal pipeline or metal piping g) Underground ground conductors electrically connected to buried metal pipelines, buried metal vessels or metal tanks sitting on grade shall be insulated. The associated ground rods shall be galvanised steel if the area requires cathodic protection. 3.3.4.5 Ground Fault Detection
When critical control systems, i.e., emergency shutdown (ESD) systems, utilise fully floating DC power where both positive and negative buses are isolated from earth ground, a selective ground fault detection system shall be incorporated to detect leakage current from field I/O wiring to ground (see Figure 3.23).
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Figure 3.23 Field Earthing / Grounding at various locations.
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Due care must be taken to ensure that circuits from one ground fault selector switch will not be cross-connected to circuits from any other ground fault selector switch (e.g., at common annunciator points, lamp test connections).
3.3.5 Field Instrument-to-Process Installation 1) Field Installation of Instruments falls into three main classes: On-line, In-line and Off-line. 1) On-Line instruments / instrument devices are those that are connected to process through block or isolating valves and include transmitters, gauges, etc. through impulse line tubing. Direct pipe or vessel mounted instruments with isolation valves are also On-line instruments, such as Pressure Gauges and Switches. 2) In-Line instruments and devices are those directly mounted on process lines and without block valves when in operation and directly exposed to pressures and temperatures of piping or equipment in or on which they are installed. a) In-line flanged flow meters (Coriolis, Electromagnetic, Turbine, PD meters, etc.; Orifice plates and Orifice Flanges, flanged multi-stage Restriction Orifice, Venturi Nozzles, Venturi Pipes, Wedge flow elements, etc.) and Instruments on Vessels (Thermowells, Multipoint Reactor T/C, Skin T/C, Temperature Gauges, etc.) are In-line items b) Tank gauges are part of In-line instruments and others are Safety valves, Breather valves, Flame Arresters and Rupture Disks c) Internal Displacers and Internal Level Switches are also In-line items d) For the purpose of this Handbook, Level gauges, Displacer Level Instruments and Level Switches, etc., as well as Shutdown valves and Control valves (they do have Block and Bypass valves) are also considered In-Line, as installation practices and protocols are similar to In-line instruments e) In-line Flow meters, Control Valves, Orifice Plates, etc., fall under mechanical / piping engineering disciplines and generally require their Contractor’s assistance but are supervised by instrument engineering disciplines f) Analyser Sampling systems are also part of In-Line but Guidelines for Installation of Analyser sampling systems are special and are usually treated as a separate class of items with safety norms defining its speciality. 3) Off-Line instruments are those that are NOT connected to process in direct contact such as Local Receiving Indicators, Signal Converters, etc. The guidelines of mounting installations on stanchions and supports for accessories applied to them as already stated and should be followed. Type of Mounting is categorised as Close Coupled, Remote Mounted and Tightly Coupled, as per API RP 551, which further helps in standardising installations. 1) Close Coupled instruments are supported by the pipe on a stand with a short section of piping or tubing connecting it to the process. API RP 551 defines close-coupled, impulse tubing / piping as within 1 m (3 ft.) 2) Remote Mounted instruments are conveniently mounted for easy access or to protect them from adverse conditions, e.g., vibration 3) Tightly Coupled instruments are supported by the process tap with a fitting-to-fitting installation or a minimum of pipe is used. The mode of process connection to instruments, often called Impulse line connections, can be by Tubing (flexible), Piping (rigid and so often called hard Piping if metallic materials are involved) or a combination of them, which is rare. The use of manifolds for isolation, equalising of pressures and drain / vent operations by use of valves may be common to both. Also, regardless of the arrangement, the drain fluid through a valve should be routed safely away from the instrument and the individual operating it. 3.3.5.1 Instrument Impulse Tubing Installation
Generally, most impulse tubing for instruments is provided with manifolds. Two versions of manifold are in use: a) the most common Mount-the-Manifold Type that allows the instruments to be removed in situ b) the older version, where Transmitter and Manifold are separately mounted and connected to Instruments by short tubing.
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This Handbook details Type 1 Installation below, unless otherwise specified. Type 2 Manifold Construction Management shall follow similar practices as applicable, except that supports now refer to instruments and not manifolds. Use of Monel or 9cr-1/2Mo tubes such as in NACE / sea water services shall also follow similar practices. A) Orientation 1) Manifold shall be mounted to the transmitter, as per Figure 3.24.
Figure 3.24 Manifold valve details.
3.3 Field Installation
2) Tap details and position of transmitters / instruments shall be as follows:
However, in some exceptional cases, use of Syphon, Condensate pots and Seal pots may be needed (to push vapour in liquid service back to line or condensate in vapour or steam service back to line to avoid measurement errors) due to difficult geographical constraints imposed on site to follow standard installations. Final orientation of tapping shall be determined in conjunction with process conditions on the project. a) Differential pressure instruments shall be located above the taps for gas and non-condensable fluids b) For liquids and condensable fluids, mounting shall be below the tapping point. Special conditions such as particles shall be clearly defined. 3) All pressure instrument with manifold block or piped manifold shall be provided with a block valve and a drain / vent facility. Exception is for those instruments with diaphragm seals where capability to depressurise the impulse line is to be provided. For this purpose, instruments with diaphragm seal, the drain / vent connection shall also be via the drip ring and piping valve 4) For steam services, pressure gauges and pressure switches shall be mounted with a steam syphon. Condensate pots shall be used in the case of electronic transmitter hook-ups on steam service. B) Guidelines on Installation 1) When instrument supports have to be fixed to fire proofed plant structures, these supports shall be welded / bolted to the steel structure before the fire-proofing is applied. In the case of already applied fire-proofing, clamping shall be considered. Type of mounting / fixing shall be clearly indicated on the applicable installation documents 2) Instrument and capillaries shall be plumb and level. Impulse lines which run at a slope shall be continuously sloped in not less than one in ten, except where otherwise specified. Direction of slope shall be downward from the process for liquid service and upward from the process for gas service 3) Tubing shall be supported and protected from vibration and physical damage by means of tubing clamps. Tubing clamps shall be stainless steel (SS 316) with polyamide internals to avoid cold spots 4) Tubing shall not be supported to handrails (or routed along handrails) 5) In locations where mechanical damage is likely, tubing may be installed in dedicated structural channel, angle or in tray (channels / angles / trays shall not be supported to process piping or utility piping) 6) No mechanical stress shall be induced upon an instrument that will cause a malfunction or error in the readout. Tubing shall not be secured directly to machinery or pipes but via supporting steel connected to columns, structure, steelworks, etc. 7) Tubing runs for instrument impulse lines shall be kept as short as possible, consistent with good practice and accessibility. Where practically possible, the length of the impulse line should not exceed 6 m 8) The tubing runs shall be kept clear from hot environments, potential fire risk areas, drainage points of condensate, water and process fluids 9) Tubing (½ ") shall be supported at least every 1000 mm 10) Intermediate tubing connections shall be kept to a minimum 11) Tubing shall not be utilised to carry the weight of pressure gauges, seal pots, etc. These items shall be supported by suitable brackets 12) Installation shall follow project approved design and detailed engineering typical standards for Instrument Impulse Hook-up Drawings and Piping and Instrumentation interface specifications for instrument interface with piping. I&C scope starts after a piping isolation block valve.
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3.3.5.2 Pipe Manifolds and Direct Mounted Instruments – Installation
Where the above tubing and fittings are not suitable for the process fluid or the process conditions and / or specific project requirements, other materials equal or better than the piping class specification shall be used. As a general rule, pipe fabricated fittings and component manifolds are assembled for those above ASME 600 class. As indicated earlier, a hard piped manifold is provided where tubing or threaded / compression fittings are not permitted. Also, recall that all materials after the first piping isolation valve are in the scope of Instrument (discipline) Contractor. Generally, the following guidelines are applied for hard piping hook-up installations: The following pipe materials are usual in any industry: a) b) c) d) e) f) g)
Carbon Steel Carbon Steel – Galvanised Alloy Steel Stainless Steel (316L SS mostly) Killed Carbon Steel Monel Duplex Stainless Steel.
Mix and match between materials is not permitted, unless approved due to non-availability. 1) Pipes and Pipe Fittings a) Impulse pipe sizes are largely ½", unless otherwise specified b) Pipe nipples longer than 150 mm (6") are not permitted in installations between fittings c) Pipe fittings and connectors consist of Unions, 90° Elbows, Tees, cross-over connectors and Plugs. All materials shall meet or exceed the piping class. For this purpose, a separate instrument piping class can be prepared to reduce the inventory of instrument piping materials d) In the case of galvanised fittings only, full couplings may be used in place of unions e) All fittings shall be forged only. 2) Connections a) Flanged end connections shall be ASME B 16.5. Rating and facing shall be matched b) Pipe threads shall be to ASME B1.20.1 (taper) – NPT only c) Socket weld ends shall be to ASME B16.11 d) Bevel ends shall be as per ASME B16.25 e) Flat ring Gaskets shall be to ASME B16.21 and Metallic Ring joint, Spiral wound metallic jacketed gaskets to ASME B16.20 f) Bolts shall be to ASME B18.2.1 and Nuts to ASME B18.2.2 g) Flanges including blind flanges, their gaskets and bolts-nuts shall be used as per piping class. Threaded flanges are not permitted, even for instrument air service. In the few places where threaded flanges are allowed, they may have to be seal welded after pre-commissioning. 3) Flange face and Finish a) Serrated Concentric to 6.3~12.5-micron Ra (125~250 micro-inch AARH) Raised Face (RF) Flange face finish requires Flat ring gasket, and Smooth finish to 3.2~6.3-micron Ra (63–125 micro-inch AARH) shall be provided with Spiral wound semi-metallic gasket, unless otherwise specified b) Octagonal rings shall only be used for RTJ flanges, including RTJ ring holders for orifice Flanges. 4) Packing and Seals a) Packing shall be non-asbestos and compatible with the metallic material in contact. Uninhibited graphite or carbontype packing is not permitted, especially when in contact with stainless steels b) Pipe Thread seal shall be Teflon tape for threaded ends up to 200°C (400°F). Above 200°C (400°F), high-temperature manganese or silicone-based sealant shall be used. 5) Threaded fittings and Exceptions a) Threaded nipples shall not be used, as a general rule. Full coupling Bull type threaded nipples are permitted with approval as an exception b) Screwed end fittings required at instrument ends (orifice tap, pressure gauges, etc.) may be seal-welded after installation / pre-commissioning for leak tightness on piping class where threaded ends are not permitted c) Nipple-to-Nipple weld is not permitted.
3.3 Field Installation
6) NACE standard a) Materials exposed to H2S laden atmospheres or in Sour Gas service shall be selected in accordance with NACEMR01 75. The chemical composition, hardness, etc., shall be controlled as specified in NACE MR01 75 b) NACE requirement must be made identifiable c) NACE MR01 75 shall be applied as a standard in the process area / unit, irrespective of the fact that the instrument(s) is not in direct contact with sour service but only in the vicinity of such applications.
3.3.6 Online Instruments Installation 3.3.6.1 Pressure Gauges and Pressure Switches
A1. Typical installation arrangements for Direct-mounted Pressure Gauges (PG) and Switches (PS) are shown in Figure 3.25. 1) Pressure gauges / switches shall be installed with material and rating according to the applicable pipe specifications on which they are mounted 2) Pressure gauge scale shall be horizontal for top-mounted items. A side-mounted pressure gauge may have vertical scale read-out. In the case of side-mounting and / or inaccessible tapping point, the pressure gauge shall be remote mounted with ½" OD tubing 3) For steam services, pressure gauges and pressure switches shall be mounted with steam syphon. Condensate pots shall be used in the case of electronic transmitter hook-ups 4) It is reiterated again that Tubing shall not be utilised to carry the weight of pressure gauges, seal pots, etc. These items shall be supported by suitable brackets 5) Installations shall be checked for protection against special conditions such as vibrations, pulsations and pressure spikes. A bracket must be installed to support the pressure gauge if the metering pipe is not able to provide adequate support. The installation location and orientation must be checked to ensure that workspaces for operating personnel are not located to the rear of the pressure gauge 6) Devices with a blow-out require a minimum spacing to the rear of 20 mm 7) When connecting the device, the pipes must be depressurised. The pressure metering pipe must be laid inclined to avoid air pockets in liquid service and condensate pockets in gas service. If the necessary incline is not achieved, then for proper measurement at suitable points, water separators or air separators need to be installed as a last resort. Note that with liquid measurement media, the pressurised connection pipe must be first degassed, since any gas bubble inclusions result in measurement error. The pressure metering pipe must be kept as short as possible and laid without sharp bends, to avoid transmission delays. If water is the fluid or used as the in-between measurement medium, as in syphon or seals, the device must be protected from frost. 8) Mounting shall be only by the right open-jawed wrench and the device is not to be twisted 9) The pressure gauges are supplied calibrated ex works or recalibration checked at workshop, so there is no need for calibration works at the installation point (or in situ). Zero-point adjustment on site is standard. However, pressure switches if required to be checked for repeatability shall be only at the workshop 10) Diaphragm seal assembly / Installation a) The diaphragm seal is intended for direct assembly.
Figure 3.25 Typical Direct PG Mounting.
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b) c) d) e)
The filled and calibrated diaphragm seal / pressure measurement instrument system must not be dismantled or altered. The seal on the filling screw must not be broken. The diaphragm must not be damaged, as scratches or indentations impair function and are points of attack for corrosion. Capillary lines must not be bent to have sharp edges (minimum bend radius 40 mm) and excess length is to be coiled using a radius of approximately 25 cm. The diaphragm seal must not be supported using the capillary line Capillary lines for differential pressure measurement instruments are run parallel as far as possible, to avoid temperature errors. Also, capillary lines are run so that they are protected against oscillations. A bracket must be installed to support the pressure gauge if the metering pipe is not able to provide adequate support over the diaphragm assembly Unless otherwise indicated, the diaphragm seal with capillary line and pressure measurement instrument are calibrated for installation at the same height. In the event that different height levels apply, the influence of hydrostatic pressure introducing errors in measurement cannot be ignored but are best avoided or must be compensated for. Collapse of the filling fluid column due to excessive height differences must also be avoided. Typically for glycerine and silicone oil, a maximum of 7 m and for halocarbon a maximum of 4 m are recommended (Figure 3.26).
3.3.6.2 Pressure and Differential Pressure Transmitters
Pressure and Differential Pressure (or DP) transmitters or Pressure Differential transmitters (PDT) apply to direct measurements as well as to indirect measurement of flow through Head meters or Level using static Head measurements or across equipment. The installation guidelines are as follows: 1) Keep impulse piping as short as possible 2) For liquid service, slope the impulse piping at least 1"/ft. (8 cm/m or most usually referred to in industry as slope 10 to 1 or 12 to 1) downward from the process towards the transmitter connection, to ensure total liquid fill without gas pockets or voids 3) For gas service, the impulse piping follows the reverse norm from the process upwards towards the transmitter 4) Impulse legs for DP or PD measurements must be at the same temperature 5) The piping must be arranged to vent all gas from its legs for liquid service and condensate must be sloped to a drain for vapour or condensable gas service. Instrument vent / drain connections, especially in coplanar flanges, must also be kept so that drain / vent connection is on the bottom for gas service and on the top for liquid service i) If a line purging is involved, the purge connection must be close to the taps and purge through equal lengths for DP and PD service. Generally, purging through the body of transmitter is to be avoided
Figure 3.26 Diaphragm assembly for Pressure gauges.
3.3 Field Installation
Certain liquids that are condensable at ambient temperatures and are cryogenic in nature are treated as Gas service with the transmitter above tap and generally installed with a steeper slope to ensure passage of liquid–vapour in equilibrium to allow for self-purging (e.g., Ethylene / Ethane Hydrocarbon – C2HC, etc.). ii) When sealing fluid is used for DP or PD service, they must be filled to the same level for both legs iii) For hot service, to avoid direct contact with sensors, the impulse length is planned long enough to cool the fluid below 120°C – the rule of thumb followed for rate of fall of temperature is 10°C per foot iv) Sediment deposits must not plug impulse piping nor shall fluids freeze within the transmitter. Schemes from API RP 551 are provided in Figure 3.27 for reference. (Close Coupled and Remote Installation guidelines) Typical mounting instruction details of transmitters from manufacturers require that for sensor protection, assembly of manifold to traditional flange, bolts must break back plane of flange web (i.e., bolt hole) but must not contact sensor module housing. All transmitter hardware adjustments are to be done during pre-commissioning to avoid exposing the transmitter electronics to the plant environment after installation.
Figure 3.27 Pressure and DP installations.
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Figure 3.27 (Continued)
3.3 Field Installation
Isolators
Figure 3.28 Draft range transmitter installation.
1) For steam service or for applications with process temperatures greater than the limits of the transmitter, blow down through the impulse piping through the transmitter is to be avoided and a note may be hung after installation for the commissioning team to flush lines with the block valves closed and refill lines with water before resuming measurement 2) Draft range pressure transmitter must be installed with the isolators parallel to the ground, as in Figure 3.28.
3.3.7 In-Line Instruments Installation – Flow Meters 3.3.7.1 General Guidelines for Flow Meters
Examples of In-line flow meters are Orifice, Venturi, Flow nozzle, Turbine, Positive Displacement (PD), Coriolis Meters, Vortex meters, Electromagnetic flow meter (Intrusive probes), Ultrasonic flow meters, etc., and any requiring flanged meter tube runs. a) Although this is applicable to all instruments, heavy duty in-line items such as flow meters require special attention to inspect and verify that the appropriate models and types / options as per approved drawings were delivered before installation b) Upon receipt of the shipment, the following shall be checked for all meter and associated accessories: Packing list against the material received and the Purchase Order, Item tags with Model name / number and Customer Tag number, etc. c) Checking the packing list against the material received and the purchase order, all items tagged with model name and customer item tag number, etc. must be checked for all meter and associated accessories d) Also, inspection of face-to-face lengths and dimensions of the received goods must be checked to be in accordance with approved drawings. This is mainly to avoid dismantling and removal and reinstallations that are expensive, especially as it may be an inter-disciplinary exercise for heavy duty items (e.g., flow meters of large size, control valves, Safety valves, etc.) e) Handling: Generally, all in-line flow meters are heavy duty items and the typical description for handling of Venturi tubes given below must be followed in principle for all in-line flow meters. Whether the handling, moving to site and installation are part of mechanical discipline, or not, it shall be supervised by I&C and responsibility lies entirely in I&C discipline’s scope. The instrument’s precision is guaranteed mainly by correct and precise installation. The metered fluid flow rate is subject to considerable error if the in-line installation of the equipment is such that vortexes and / or distortion of the velocity profile are generated by an incorrect alignment of the parts. A typical general handling detail is given below and is applicable to all: ●
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The materials are shipped packed in cases or in wooden and / or sea-going plywood crates. Moving the crates from the means of transport must be carried out with care The handling instructions on the exterior of the crate must be observed. The crate must not be overturned
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The lifting ropes must be positioned at the reinforced points for slings indicated on the crate with the international graphic symbols ● In using a forklift to raise the crate, care must be taken so as not to damage its planking ● For all packages and in any case, those exceeding 4 tons at the centre of the gravity point, if indicated on the crate, must be located ● The material must be lifted by means of adequate equipment using adequate ropes, chains or belts to make secure slings for the materials. The eyebolts or, without them, specific zone showed in the manual, may be used for applying the slings ● A measuring flange or a flow section must not be lifted by means of the hole in the orifice plate handle ● Handling of Electronics include: – Unpacking the flow meter electronics with care, remove the electronics enclosure, the transducers and the cables from the shipping containers. Before discarding any of the packing materials, account for all components and documentation listed on the packing slip. The discarding of an important item along with the packing materials is all too common. If anything is missing or damaged, contact the manufacturer immediately for assistance – Selecting suitable sites for the electronics enclosure and the transducers – Installing the transducers – Installing optional temperature transmitters – Installing the electronics enclosure – Wiring the electronics enclosure – Most electronic instrument associated with flow meters contain electrostatic sensitive circuit boards. Electrostatic safety precautions should be taken to prevent damage. f) General principles for Installation 1) Flow Direction and Straight lengths i) Flow meters must be installed in line to the flow direction reported on marker plate ii) The straight length shall be free of protrusions from gaskets, welds, etc., in all long or short meter tubes iii) Manufacturer’s recommendation for upstream-downstream lengths shall not be ignored. Where there is a large availability of straight lengths, the flow meter must be positioned so that the 80% of these straight lengths come before and the other 20% after the unit. Sometimes, this recommendation is made from site altering drawing details based on piping modifications in situ iv) The use of straighteners (flow conditioners) is considered in those cases where there are not sufficient lengths of straight-line run and installation practices applicable to meter is also applicable meter runs v) Reducers, if required, shall preferably be concentric only and eccentric reducers shall be avoided. The extent of reduction shall not exceed 0.7. 2) Links and assembly For measuring components and assembly (flow meters) to be installed between flanges, the linkage tightening must be carried out using the following sequence as per manufacturer’s instruction and project piping specification: i) The linkages must be tightened using dynamometric spanners or keys ii) Installation on piping with Butt Welding ends (where applicable): The qualified welding specification for the installation must be applied to all the welded joints, observing the prescribed parameters and carrying out any thermal treatment demanded iii) When tightening the process bolts, the torque specifications of the flow meter manufacturer shall be followed. Tighten the end flange of the meter bolts in a “star” pattern, to avoid localised stresses on the gaskets. 3) Bolting and Gaskets i) The required bolt load for sealing the gasket joint is affected by several factors, including operating pressure, gasket material, thickness and condition. A number of factors also affect the actual bolt load resulting from a measured torque, including condition of bolt threads, friction between the nut head and the flange, and parallelism of the flanges ii) Due to these application-dependent factors, the required torque for each application may be different. Follow the guidelines outlined in the ASME PCC-1 for proper bolt tightening. Make sure the flow meter is centred between flanges of the same nominal size as the flow meter iii) When installing a flow meter between the flanges, installation bolts, nuts and gaskets are often supplied by the piping / mechanical team. Proper installation shall be co-ordinated between the teams iv) The gasket provided must be centred by its outer ring and the inner ring should prevent soft material from protruding into the pipe, causing flow pattern disturbance. ●
3.3 Field Installation
4) Installation of Electronics i) When the remote electronics (transducer) type is ordered (e.g., for Vortex flow meters, Ultrasonic flow meters), mount the bracket and electronics housing in the desired location. Typically, the enclosure is mounted as close as possible to the transducers. When choosing a site, make sure the location permits easy access to the electronics enclosure for programming, maintenance and service ii) For compliance with the European Union’s Low Voltage Directive (2006/95/EC), the unit may require an external power disconnect device such as a switch or circuit breaker. The disconnect device must be marked as such, clearly visible, directly accessible and located within 1.8 m (6 ft) of the transmitter iii) The housing can be repositioned on the bracket to facilitate field wiring and conduit routing. The coaxial remote cable, if any, cannot be field terminated or cut to length. Coil any extra coaxial cable with no less than a 2" (51-mm) radius. To prevent moisture from entering the coaxial cable connections, install the interconnecting coaxial cable in a single dedicated conduit run or use sealed cable glands at both ends of the cable iv) Electronic parts (e.g., sensors) may require to be enclosed. Extensions to provide enclosures meant to keep electronics at a moderate temperature shall not be thermally insulated or traced v) The entire electronics housing may be rotated in 90° increments for easy viewing. Do not rotate the housing while the sensor cable is attached to the base of the housing. This will stress the cable and may damage the sensor vi) Prevent condensation in any conduit from flowing into the housing by mounting the flow meter at a high point in the conduit run. If the flow meter is mounted at a low point in the conduit run, the terminal compartment could fill with fluid. If the conduit originates above the flow meter, route conduit below the flow meter before entry. In some cases, a drain seal may need to be installed. A proper conduit installation is for a Vortex flow meter (or, for that matter, any instrument / transmitter vertically) is to bend the conduit downwards to avoid condensation collection at instrument housing. vii) Follow manufacturer’s recommendations for proper termination of signal cables in the flow meter electronics and for electronics grounding and plug and seal unused conduit connections. Use pipe sealing tape or paste on threads to ensure a moisture-tight seal viii) For electronic transmitter housings shipped with a cover jam screw, the screw should be properly installed once the transmitter has been wired and powered up. The cover jam screw is intended to disallow the removal of the transmitter cover in flameproof environments without the use of tooling. Application of excessive torque may strip the threads ix) Proper grounding of the transducer chassis is required to prevent the possibility of electric shock x) As indicated under electrical fittings installation practice earlier, it is emphasised again here that Flameproof Enclosure Ex d protection type shall only be opened when power is removed. Closing of entries in the device must be carried out using the appropriate certified Ex d cable gland or blanking plug xi) For Type n protection type in accordance with IEC transmitters, closing of entries in the device must be carried out using the appropriate Ex e or Ex n cable gland and metal blanking plug or any appropriate ATEX or IECEx approved cable gland and blanking plug with IP66 rating certified by an EU approved certification body. 5) Flow meter high temperature mounting The maximum temperature for integral electronics is dependent on the ambient temperature where the flow meter is installed. General, whether integral or remote, the electronics in the field must not exceed manufacturer recommended ambient temperature range. The following orientations are recommended for applications with high process temperatures: ● Install with electronics head beside or below process pipe ● Insulation around pipe may be necessary to maintain ambient temperature below manufacturer’s recommended ambient temperature range ● Insulate pipe and meter body only. Do not insulate support tube bracket so heat can be dissipated. 6) Flow meter Steam installations Vendors recommend to avoid installation under conditions that may cause a water-hammer condition at start-up due to trapped condensation. This requires upstream and downstream piping to be never above the instrument mounting datum. 7) External pressure / temperature transmitters for Mass flow compensation
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For density compensation, the pressure tapping and thermowell should be located at minimum one pipe diameter (1D) upstream and five pipe diameters (5D) downstream of any unidirectional meter respectively. However, when using pressure and temperature transmitters in conjunction with flow meters such as Vortex flow meters for compensated mass flows, most vendors recommend to install the pressure transmitters at least 4D (D = ID of pipe) downstream of the flow meter, and temperature transmitter at least 6D downstream of the flow meter also. 8) For vibration avoidance / reduction, if necessary, the pipe must be supported at one or either ends of the meter or valve to prevent excessive movement 9) Ultrasonic, Coriolis and Vortex meters are susceptible to oscillating flows and mechanical vibration. If the frequencies enter their measuring frequency range, major systematic or random errors are introduced 10) Head meter installations In differential pressure flow devices, impulse lines are the weakest components and incorrect installations will lead to additional errors in the flow measurement. Hence the emphasis on tube and tube fittings installation in earlier sections. Preferably each instrument should have its own process tap. However, when multiple instruments are manifolded from a single process tap, separate block and bleed valves should be provided at each instrument. For the details of installation guidelines for pressure / differential pressure associated with head flow meters (Orifice, Venturi, flow nozzle, etc., please refer to Section 3.3.6.2. Only flow device installation is discussed below). 3.3.7.2 Orifice Plate and Flanges and Restriction Orifices
a) The installation requirements for Orifice plates shall be as per ISO-5167–1. Ample space shall be provided to allow rodding out of process connections and removal of orifice plate, nuts and bolts. Usually, a spreader bar is avoided in use on orifice flanges; instead, the jack bolts provided at 180 degrees of each other are used, to remove or insert plates, wherever possible. b) Separate taps are used for Basic Process Control System (BPCS) and Safety Instrument Systems (SIS) transmitters / instruments. However, multiple transmitters (for various ranges for reasons of rangeability) need not have separate taps – in fact, such arrangements often add to compounding risks on installations c) Orifice flow meters may be installed in vertical lines, with the flow in the upwards direction for liquid and gas, ensuring the pipe runs “full” of fluid. For steam and wet gas applications or for gas containing particles, the flow direction shall be downwards. Liquid meters in horizontal lines shall not be installed at the highest piping point where gases are likely to collect and be hard to remove d) Gas meters in horizontal lines shall not be installed at the lowest piping point where liquids are likely to collect and be hard to remove e) The installation checks for Measurement Orifice plate require the following: ● For Normal measurement – Orifice plate tag plate details – Orifice Bore ID – upstream – Upstream and downstream lengths ● For Gas Custody Transfer – Orifice plate tag plate details – Orifice Bore ID – upstream – Upstream and downstream lengths – Pipe ID at five equidistant radial locations and up to 5D upstream and 5D downstream – ID match between Flange bolt circle and Orifice plate circle diameter – for concentricity check. f) Installation applicable to Restriction Orifices (RO) only: 1) Generally, no minimum straight run length is specified for RO but some RO’s (designed based on less than / greater than Beta ratio basis) may require it as per design standards or as per manufacturer’s recommendations, to avoid the reduction in its performance 2) The flanged RO is installed between two mating pipe flanges in the pipe work. References to overall assembly length and orientation with appropriate Piping Isometrics references during installation and associating with piping discipline is a common practice 3) The handle of the orifice plate may have the word “UPSTREAM” stamped on one side, even for RO and in particular where the RO plate has a bevel exit as in a measurement Orifice plate and so installed accordingly.
3.3 Field Installation
g) Pipe flanges must be parallel and properly aligned to prevent damage to the RO, using bolt hole alignment h) Installation steps applicable for installing measurement orifice and restriction orifice plates 1) Removing pressure and draining the pipe assembly prior to installing or removing the orifice plate 2) If the process fluid is caustic or otherwise hazardous, drains have to be necessarily piped or tubed to closed systems with the instructions highlighted in P&IDs and identified as Hazardous to prevent mishap to operators / technicians 3) It is preferable to work with piping drawings and isometrics’ references to determine proper installation of the orifice / restriction orifice assembly in pipe runs. Accessibility is often an issue for head flow meters at site 4) The plates and flange assembly must be installed in the proper flow direction and orientation relative to the pipe and the fluid flow with checking of the mark UPSTREAM on the paddle. The upstream side of the orifice plate is obviously the one with the sharp square edge. This side is identified by the “INLET” or “UPSTREAM” word stamped on the handle, on the orifice plate inlet face or by an arrow on the marker plate (the orifice bevel must always be on the downstream side). The orifice plates intended for reverse flow (bi-directional flow) do not require bevel / bevel positioning but still may have both “Upstream” and “Downstream” marking and installed accordingly. Over time, it helps to identify loss of sharp edge due to more used flow direction operationally and its restoration for accuracy. 5) The orifice plate applied vent or drain hole runs shall be positioned to 90° above horizontal. Orifice plate with drain or vent holes, installed in horizontal lines, must have the handle of measuring unit positioned on the vertical axis. The orientation of the drain / vent holes is automatic, since they are lined up with the handle. In case the restriction orifice plate has bleed holes (vent or drain), the RO plate shall be installed vertically in the horizontal pipe line. The vent hole shall be located at the top of the pipe inside wall for liquid service. The drain hole shall be located at the bottom of the pipe inside wall for gases and steam service. If there is no vent / drain hole, RO paddle orientation for easy reading access may be taken into account. 6) The orifice plate and the gaskets should never be installed bent. Both the orifice plate and the gaskets must be centred on the axis of the pipe. The maximum error of concentric positioning of the orifice plate must be within ± 0.8 mm. The gaskets positioning may be slightly less critical than the orifice plate one, but care must be taken to avoid protrusion within the pipe. 7) After placing the flanged plate within the pipe work, the plate, gasket and flange union are installed as per plant standards or per manufacturer’s recommended specifications. The plate is centred using centring ring and bolt hole alignment and guided by Jack-screws to assure the piping on both sides of the flanged plate section(s) is properly aligned before tightening the bolts. The gasket tightening is critical to meet the surface finish and type of gasket used and mounting flange bolts must be tightened to proper torque values. Re-use of gaskets is not permitted. 8) After installation, check for leaks and before commissioning the assembly. 3.3.7.3 Venturi Tubes
Venturi tubes shall be installed per ISO5167–1 (including the minimum straight length requirements). Some Venturis are planned for bidirectional flow and installation requires additional precautions similar to upstream details as per standards and to be followed. Other details are covered under General Guidelines. 3.3.7.4 Flow Nozzle
No counter-flow or flow bi-directional is allowed in the case of flow nozzle (see Figure 3.29). Other details are covered under General Guidelines. 3.3.7.5 Wedge Flow Meter
i) A horizontal installation is recommended for all WEDGE elements rotated 45° to approximately 90° along the pipe centre line. This method of mounting allows for free passage of solids and eliminates air entrapment at the transmitter connection.
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Figure 3.29 Venturi (D–D/2) and Flow Nozzle – as per standards.
Other positions are acceptable, provided proper venting of the transmitter is accomplished and differences in lead line elevations are considered. For clean liquid service, tap locations are suggested to be below the pipe centreline. For dirty liquid service, service taps should be positioned such that all are self-draining (i.e., triple taps units will be at the 3, 8 and 12 o’clock positions). Dirty liquid service can be any process where the fluid may settle, cake-up or settle- up within the tap chambers (see Figure 3.30). Examples of dirty liquid service are waste streams, coke slurries, black liquor, fluids with high particulates and the like.
3.3 Field Installation
Figure 3.30 Wedge flow meters.
ii) Vertical installations may introduce a slight hydrostatic head effect which must be considered when zeroing the transmitter iii) All WEDGE flow elements require a gasket between the process line connection and the mating flange. This gasket is occasionally not provided by the vendor and therefore the contractor needs to select gaskets that are able to withstand the maximum process temperature and pressure and to resist corrosive attack from the process itself iv) Obviously, the high-pressure connection is always on the upstream side of the flow direction arrow and the lowpressure connection on the downstream side. Fittings used must be able to withstand the process temperature and pressure conditions as well as provide proper corrosion resistance. 3.3.7.6 Vortex Flow Meter
i) The Flowmeter may be installed with a minimum of 10 straight pipe diameters (10D) upstream and five straight pipe diameters (5D) downstream by following the K-factor corrections as per Manufacturer’ recommendation. The Manufacturer may recommend “No K-factor correction” if straight pipe diameters upstream and straight pipe diameters downstream exceed certain lengths, say 35D upstream and 5D downstream. ii) When integral temperature sensor is ordered with vortex flowmeter, follow Manufacturer guidelines to install for its proper functioning iii) Vortex flowmeter ordered with painted meter body may be subject to electrostatic discharge. To avoid electrostatic charge build-up, do not rub the meter body with a dry cloth or clean with solvents iv) Vortex Flow meter mounting: As is common with such types of meters (head type meters too), for gas flow service in a vertical pipe, flow should be downwards; and for liquids upwards, so that the line is always run full of fluid at the meter. However, the vortex flowmeter may be installed in any orientation without affecting accuracy, if allowed by manufacturers. For steam and fluids with small solids content, it is recommended to have the flow meter installed with the electronics to the side of the pipe. This will, say manufacturers, minimise potential measurement errors by allowing the condensate or solids to flow under the shedder bar without interrupting the vortex shedding. Meter body with electronics installed above the pipe in a vertical plane is a standard installation. 3.3.7.7 Ultrasonic Flow Meter Head
i) An Ultrasonic flow cell or meter run tube is the section of pipe where the probes are mounted. It can be created either by mounting the probes on the existing pipeline or by mounting them on a spool piece (Figure 3.31). ii) A spool piece is a separately manufactured pipe section, matched to the existing pipe, which contains the probes. This approach allows the transducers to be aligned and calibrated before inserting the spool piece into the pipeline iii) Ideally, choose a section of pipe with unlimited access; for example, a long stretch of pipe that is above-ground. However, if the flow cell is to be mounted on an underground pipe, dig a pit around the pipe to facilitate installation of the transducers
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Figure 3.31 Ultrasonic Flow meter.
iv) For a given fluid and pipe, transmitter’s accuracy depends primarily on the location and alignment of the transducers v) Probes shall not be installed bent, as it affects accuracy. The probes of Ultrasonic meters need alignment (as do in some cases of Electromagnetic flow meters). Probes must be rigidly mounted vi) Follow the manufacturer’s guidelines for straight length requirements for upstream and downstream of the flow cell. In general, locate the transducers so that there are at least 10 pipe diameters of straight, undisturbed flow upstream and 5 pipe diameters of straight, undisturbed flow downstream from the measurement point. Undisturbed flow means avoiding sources of turbulence in the fluid such as valves, flanges, expansions and elbows; avoiding swirl; and avoiding cavitation vii) The manufacturers recommend locating the transducers on a common axial plane along the pipe. Locate the transducers on the side of the pipe, rather than the top or bottom, since the top of the pipe tends to accumulate gas and the bottom tends to accumulate sediment. Either condition will cause increased attenuation of the ultrasonic signal. There is no similar restriction with vertical pipes. However, vertical pipes should be avoided in order to insure a full fluid-filled pipe at the measurement point viii) Locating the electronics enclosure as close as possible to the flow cell / transducers, preferably directly on the flow cell is recommended. However, some manufacturer can supply or recommend types of transducer cables up to 1,000 ft (300 m) in length for remote location of the electronics enclosure. If longer cables are required, consult the manufacturer for assistance ix) When installing the transducer cables, always observe established standard practices for the installation of electrical cables. Do not route transducer cables alongside high amperage AC power lines or any other cables that could cause electrical interference. Also, protect the transducer cables and connections from the weather and corrosive atmospheres x) Optional temperature transmitters may be installed as part of the flowcell, near the ultrasonic transducer ports. 3.3.7.8 Coriolis Flow Meter
i) As stated previously on general Guidelines a) Make sure that the hazardous area specified on the approval tag is suitable for the environment in which the meter will be installed b) Verify that the local ambient and process temperatures are within the limits of the meter c) The Coriolis may have an integral transmitter (i.e., no wiring is required between the sensor and transmitter) or have remote mounted electronics d) The signal and power wiring instructions vary according to type and manufacturer’s instructions must be followed. There is a maximum permissible cable length between sensor and remote mounted transmitter, which must be complied e) The Coriolis meter requires a completely pipe-, stress- and vibration-free environment to function and are more stringent on these aspects as compared to other in-line meters (see Figure 3.32). Especially, the meter process connections shall not be used as pipe supports and bypass loops / valves are to be supported separately. However, the
3.3 Field Installation
Coriolis Meter orientation for Liquid flow
Coriolis Meter orientation for Gas flow
Coriolis Meter orientation for Slurry/ Trace solid flow
Other orientations are recommended by manufacturers in their User manual. Refer to them to verify for other alternate configuration in field if shown in piping isometric drawings
Figure 3.32 Coriolis Flow meter – preferred Orientations.
ii)
iii) iv)
v)
vi)
Coriolis sensor does not require external supports. The flanges will support the sensor in any orientation. Some sensor models installed in very small, flexible pipeline may have optional installation instructions that allow for external supports. f) Lifting instructions for the Coriolis meter is the same as for other in-line meters ● Lift a meter by its case / flange, as recommended by manufacturers. Do not lift a meter by its electronics (junction box, transmitter, or any electrical fittings) or by its purge fittings. It may be useful to identify the meter’s centre of gravity ● Use general practices to minimise torque and bending load on process connections ● An integrally mounted junction box or core processor can be rotated to one of eight possible positions in 45° increments ● Where the sensor and its electronics are designed for wall mounted or pipe mounted, install with appropriate accessories as per manufacturer’s recommendation. Grounding as per manufacturer’s instructions is critical as Coriolis transducers are frequency / pulse measuring instruments. For optimal performance, install the sensor in the preferred orientation. However, the sensor will work in any orientation as long as the flow tubes remain full of process fluid. If the sensor is installed in a vertical pipeline, liquids and slurries should flow upward through the sensor. Gases should flow downward. Although the Coriolis meter has software selectable flow directions, install the meter so that the flow direction arrow on the sensor as received matches the actual forward flow of the process. The Coriolis meter requires a downstream tight shut-off valve to ensure actual zero flow before establishing the meter’s zero point There are no pipe run requirements for Coriolis sensors and so straight runs of pipe upstream or downstream are not necessary. But for reasons other than flow meter accuracy, manufacturers may suggest some straight run requirements when the meter is also used for density measurements The Coriolis sensor is susceptible to the ambient temperature if outside of the range permissible for the electronics; the electronics may then be remotely located as indicated by the manufacturer temperature limit graphs The difference between the process fluid temperature and the average temperature of the case must be less than the manufacturer’s recommendation. The extended-mount electronics option allows the sensor case to be insulated without covering the transmitter, core processor or junction box, but does not affect temperature ratings. When insulating the sensor case at elevated process temperatures (above 140°F), it is necessary to ensure electronics are not enclosed in insulation as this may lead to electronics failure. For optimal cleanability and drain ability ● If possible, install the sensor in a vertical pipeline with the process fluid flowing upwards through the sensor ● If the sensor must be installed in a horizontal pipeline, drainage is accomplished by air purge evacuation of the pipeline circuit ● For clean-in-place (CIP) applications, consult with the manufacture for the recommended flow velocity, usually at least 1.5 m s–1 for cleaning the sensor ● The gap between the electronics housing and sensor body should be inspected periodically. Manually clean this gap when necessary
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Generally, if flow is upwards for gas flow, the drain from the meter is piped downwards for self-draining arrangement from the body drain provided in the meter body.
3.3.7.9 Electromagnetic (EM) Flow Meters
i) Handling Instructions specific to EM flow meters ● The protective covers mounted on the two sensor flanges guard the PTFE lining, which is turned over the flanges. Consequently, do not remove these protection plates until immediately before the sensor is installed in the pipe ● Protection plates must remain in place while the device is in storage too ● Make sure that the lining is not damaged or removed from the flanges ● Manufacturers recommend use of webbing slings slung round the two process connections. Do not use chains, as they could damage the housing. Use only the metal eyes on the flanges for transporting the device, lifting it and positioning the sensor in the piping ii) Guidelines specific to EM flow meters a) Bolts, nuts, seals, etc., are generally not included in the scope of supply by manufacturers and must be supplied by the relevant piping or mechanical team or by the installation party responsible for construction b) The sensor is designed for installation between the two piping flanges. It is essential that the necessary screw tightening torques are observed as per manufacturer recommendations c) If grounding discs are used, follow the mounting instructions which will be enclosed with the shipment d) Some manufacturers recommend not to install seals for earthing continuity. Consult with the manufacturer for recommendation. If seals are provided, make sure that the seals do not protrude into the piping cross-section. e) Do not use electrically conductive sealing compound such as graphite. An electrically conductive layer could form on the inside of the measuring tube and short circuit the measuring signal f) Where necessary, special ground cables can be ordered from the manufacturer as accessories for potential equalisation. Consult with the manufacturer for recommendations g) Depending on the application and the length of the pipe, the sensor must be supported or more securely mounted if necessary. Particularly when using process connections made of plastic, it is essential that the sensor be mounted securely. A wall mounting kit for this purpose can be ordered separately as an accessory from the manufacturer h) In case the process connections are made of plastic (e.g., flanges or adhesive fittings), the potential between the sensor and the fluid must be equalised using additional ground rings. If the ground rings are not installed, this can affect the accuracy of the measurements or cause the destruction of the sensor through the galvanic corrosion of the electrodes. Depending on the option ordered, plastic rings may be installed at the process connections instead of ground rings. These plastic rings serve only as spacers and have no potential equalisation function. In addition, they provide a sealing function at the interface between the sensor and process connection. For this reason, with process connections without ground rings, these plastic rings / seals must not be removed, or must always be installed. i) Ensure that the ground ring is compatible with the material used for the electrodes. Otherwise, there is a risk that the electrodes may be destroyed by galvanic corrosion Ground rings, including the seals, are mounted within the process connections. Therefore, the fitting length is not affected. j) In case of welding the transmitter into the pipe (weld nipple), a risk of electronics being destroyed is present. Ensure that the welding system is not grounded via the sensor or transmitter Secure the sensor using several welding points in the piping. A welding jig suitable for this purpose can be ordered separately as an accessory. Loosen the screws at the process connection flange, and remove the sensor including seal from the piping. Weld the process connection into the pipe. Mount the sensor back into the pipe. When doing so, make sure that the seal is clean and positioned correctly. k) For the high-temperature version (with PFA lining), vendors provide a housing support for the thermal separation of sensor and transmitter. The high-temperature version is always used for applications in which high ambient temperatures are encountered in conjunction with high fluid temperatures. The high-temperature version is obligatory if the fluid temperature exceeds the manufacturer recommendation l) Pipes generally have to be insulated if they carry very hot fluids to avoid energy losses and prevent accidental contact with pipes at temperatures that could cause injury
3.3 Field Installation
Guidelines regulating the insulation of pipes have to be taken into account as there is a risk of electronics overheating. The housing support dissipates heat and its entire surface area must remain uncovered. Make sure that the sensor insulation does not extend past the top of the two sensor half-shells. m) Where required, rotate the instrument housing display to suit field operator view and access. Instrument housing may be panel mounted, wall mounted or pipe mounted as required. Ensure that necessary mounting kits are procured and available on site from the manufacturer for proper mounting n) The accumulation of air or gas bubbles in the measuring tube could result in an increase in measuring errors Avoid the following locations: ● at the highest point of a pipeline at the risk of air accumulation ● directly upstream from a free pipe outlet in a vertical pipeline. o) Do not install the sensor on the intake side of a pump. This precaution is to avoid low pressure and the consequent risk of damage to the lining of the measuring tube p) It might be necessary to install pulsation dampeners in systems incorporating reciprocating, diaphragm or peristaltic pumps q) Partially filled pipes with gradients necessitate a drain-type configuration. The Empty Pipe Detection (also called No-Flow or Zero-Flow Detection) function offers additional protection by detecting empty or partially filled pipes. To avoid risk of solids accumulating, do not install the sensor at the lowest point in the drain. It is advisable to install a cleaning valve at the low point r) Install a syphon or a vent valve downstream of the sensor in down-pipes longer than 5 m (16 ft.). This precaution is to avoid low pressure and the consequent risk of damage to the lining of the measuring tube. This measure also prevents the system losing primary pressure, which could cause air inclusions s) Orientations ● Most manufacturers require an upstream length of greater than 5D and downstream of 2D. A bend upstream shall also be of length 5D thereafter, for guaranteed accuracy ● An optimum orientation position helps avoid gas and air accumulations, and deposits in the measuring tube ● A vertical orientation is ideal in the following cases thereafter: – For self-emptying piping systems and when using empty pipe detection – For sludge containing sand or stones and where the solids cause sedimentation. ● The measuring electrode plane should be horizontal. This prevents brief insulation breakdown of the two electrodes by entrained air bubbles. It is recommended by some manufacturers to have a syphon arrangement downstream with a vent valve and then pipe dipping down to at least 3D below the meter – a requirement often in waste water and sludge treatment intakes. t) Empty Pipe Detection ● An often missed-out installation aspect is the Empty Pipe Detection (EPD) functioning correctly with the measuring device installed horizontally only when the transmitter housing is facing upwards. Otherwise, there is no guarantee that EPD will respond if the measuring tube is only partially filled. The EPD should be able to detect partially filled line. The illustration in Figure 3.33 is typical of several manufacturer’s design on electrode locations to be maintained during installation. ● Inlet and Outlet runs – If possible, install the sensor in a location upstream of fittings such as valves, T-pieces, elbows, etc. – Compliance with the following minimum requirements for the inlet and outlet runs is necessary in order to ensure measuring accuracy. The manufacturer may be consulted for right run length requirements. Generally, Inlet run: 5 × DN; Outlet run: 2 × DN. u) Anti-Vibration support ● Secure and fix both the piping and the sensor if the vibrations are severe ● It is advisable to install sensor and transmitter separately if vibration is excessively severe. Consult the manufacturer for permissible vibration for the sensor and transmitter ● Manufacturers recommend that, if the nominal diameter is larger than a certain size, mounting the sensor on a foundation of adequate suitable adapters (double-flange reducers) can be used to install the sensor in largerdiameter pipes. The resultant increase in the rate of flow improves measuring accuracy with very slow-moving fluids. If the nominal diameter is larger than a certain size mounting, the sensor on a foundation is adequate ● Do not support the weight of the sensor on the metal casing. The casing would buckle and damage the internal magnetic coils.
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Figure 3.33 Mag Flow meter – Empty Pipe Detection.
v) Length of connecting cable In order to ensure measuring accuracy, the manufacturers request compliance to the following instructions when installing the remote version: ● Secure the cable run or route the cable in an armoured conduit. Movement of the cable can falsify the measuring signal, particularly if the fluid conductivity is low ● Route the cable well clear of electrical machines and switching elements ● Ensure potential equalisation between sensor and transmitter, if necessary ● The permissible cable length Lmax depends on the fluid conductivity. To finalise, consult the manufacturer ● The maximum connecting cable length is normally less than 10–15 m when empty pipe detection is switched on (for most manufacturers). 3.3.7.10 Variable Area Flow Meter (Rotameter)
a) Handling of Rotameters i) The general principles of handling described earlier apply to the Rotameters also ii) The painted surface of the device may be cleaned only using a moist cloth. b) Installation Guidelines i) The flow meter is installed vertically in the piping. The measuring media must flow from bottom to top ii) The piping should the same size as the connection size of the flow meter iii) Keep the device as far as possible from pipe vibrations and powerful magnetic fields iv) Inlet and outlet straight length sections are generally not required for liquids v) For gaseous measuring media, the manufacturers recommend an undisturbed inlet length of five times (5D) the inside diameter of the piping to be followed. Additional measures such as flow straighteners or perforated plates may be necessary for highly unbalanced flow profiles vi) Care should be taken to avoid flow turbulence, pulsations, pressure shocks and other flow instabilities in order to prevent measuring inaccuracies, increased wear or damage vii) To avoid pulsating flow of the measuring medium, the optional float damping may be necessary on site viii) With low flow amounts and low operating pressure, so-called compression oscillations of the float can occur. If the maximum upstream pressure listed in the specifications is not reached, the flow meter is required to be equipped with a gas damper. Additionally, piping length is minimised between the flow meter and the closest up or downstream throttling location ix) Especially when measuring gases, it is possible that pressure or shock waves can occur when fast opening solenoid valves are employed and the piping cross-sections are not throttled, or if there are gas bubbles in liquids. As a result of the sudden expansion of the gas in the piping, the float is forcibly driven against the upper float stop. Under certain conditions, this can lead to destruction of the device. Gas damping is not suited to compensating for pressure shocks x) Presence of solids above micron size is not acceptable and in magnetic rotameters, such trace solids in flow medium, if any, must be non-magnetic or removed with magnetic separators ahead
3.3 Field Installation
xi) In view of the above restrictions, installation details are reviewed while commissioning instruments more thoroughly xii) Check to avoid contamination of gaseous measuring media and gas inclusions in liquid measuring media in installation, particularly in chemical additions and purge installations xiii) Block and bypass valves are required and it is ensured that throttle valves are used as pressure must be equalised slowly between upstream and downstream gradually to avoid slamming of float xiv) All general installation guidelines for rotameters described earlier apply. The following points specific to the rotameter are highlighted: ● ● ●
●
As in other flow meters, the flow direction must correspond to the direction indicated on the device, if labelled Position the meter tube coplanar and centred between the piping Sensor insulation: The device may be insulated. The maximum permissible thickness of the insulation normally corresponds to the flange diameter; however, this shall be verified with the instrument manufacture and their guidelines shall be adhered to Earthing is recommended for Rotameter transmitters.
The instrument housing must be correctly earthed in order to ensure proper function and safe operation. Ensure that when connecting the protective earth (PE), there are no potential differences between PE and potential equalisation, even in the event of a fault. 3.3.7.11 Turbine Flow Meter
The general guidelines are common to the other flow meters detailed earlier. However, some that may need specific remention with respect to Turbine flow meters are only reiterated below. a) Handling Inserting the forks of a forklift into the bore when moving the turbine meter is prohibited, as it may cause the meter to become unstable, resulting in serious injury or equipment damage. Use of a lifting hook provided with the meter body is the desired approach. As is common with in-line meters with head electronics, all manufacturers advise never to attempt to lift the turbine meter by wrapping slings around the electronics enclosure. Never attempt to lift the turbine meter using only one sling around the turbine meter. Always use two slings wrapped around each end of the body. If the slings do come in contact with the electronics, use a spreader bar on the sling to prevent contact with the electronics. A choker style sling with a spreader bar is recommended. Only use slings with ratings that exceed the weight to be lifted. b) Component Inspection Visually inspect all components listed below for shipping damage. Evaluate the system setup to ensure that all components are in the correct sequence for accurate product measurement, viz. isolation valve, strainer, flow straightener, turbine meter, downstream section, control valve, etc. ● The meter consists of two main parts: Local Mounted Enclosure assembly and the meter body housing assembly. For certain functions, the meter will have a Remote Mounted Enclosure. The Remote Mounted Enclosure is specifically designed for high temperature applications. The Local Mounted Enclosure assembly may be an explosion-proof, weather-resistant housing for dual pickoffs, as well as an encapsulated preamplifier. It also serves as the mechanical mounting connection necessary for local and remote accessories. ● The Local Mounted Enclosure assembly contains a mounting bracket and a preamplifier which works with two standard pickoff coils mounted into the meter housing. The electrical enclosure contains an external and an internal grounding lug. The two enclosure openings may be plugged with stainless steel plugs ● The connecting cable is the connection between the Preamplifier that is assembled into a Remote Mounted Enclosure, not more than 6 m from the centre of the meter housing to the centre of the Remote Mounted Enclosure. Maximum allowed distance shall be confirmed with the manufacturer and accordingly the cable shall be provided ● The electrical enclosure should contain an external and an internal grounding lug which need to be grounded as per manufacturer’s guidelines ● The Turbine meter may be supplied with two Local Mounted Enclosures, offering up to four pulse outputs. Confirm the design and accordingly proceed with installation
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Remote Mounted Enclosure can be either pipe mounted or wall mounted. Confirm the design and install with proper mounting brackets and screws ● There are many sensitive components within a Turbine meter, as it has a rotor part (anti-rotation clamps, special jewel thrust bearings and a very sensitive Pick-off transducer coil, etc.). The manufacturers provide upstream and downstream cones that also need centring and alignment. Handling therefore requires a special knowledge of components inside a Turbine meter to avoid accuracy issues later. c) Installation i) Turbulent flow is detrimental and affects Turbine meter linearity. It can cause nonhomogeneous fluid cross-section and inconsistent back pressure, possibly resulting in cavitation. To correct for the flow characteristics, upstream and downstream piping lengths also matter to a Turbine flow meter ii) All piping must be in the same diameter as the Turbine meter iii) A straight run of pipe of 10–20 pipe diameter (10D–20D) length minimum is recommended. If an integral flow conditioner is used, this length can be decreased. The flow stream must be free of swirl for a turbine meter to perform consistently and accurately. Although the internal assembly supports of a Turbine meter offer a slight straightening effect, additional flow conditioning in the form of straightening vanes or tube bundles or flow conditioning plate are usually part of Turbine meter assembly for large sizes and all need a true straight-line installation as assembly (see Figure 3.34). iv) Flow straightening devices must be installed directly upstream of the Turbine meter and should not contain flow restricting devices that could cause reversal of the flow straightening effect. Pipe fittings such as elbows and tees, and piping components such as valves and strainers, should be located far enough upstream to dissipate any flow disturbance before it reaches the Turbine meter. The use of flow straighteners or a flow conditioning plate greatly influences meter performance v) Turbine meters are viscosity sensitive. The meter is affected by specific gravity which may influence performance. Sufficient back pressure on the Turbine meter is required to prevent flashing and cavitation. The resulting flashing and cavitation are extremely damaging to the flow meter and pipe work. Hence, construction is very important vi) The Turbine metering system should have a flow rate control valve located at a convenient distance downstream of all measurement equipment to avoid overspeed. The function of the control valve is to limit and maintain system pressure on the meter. This avoids cavitation. During installation, it is also checked that the flow valve is left closed vii) The correct size strainer upstream of the meter protects it from foreign material damage. Recommended mesh sizes shall be verified with strainer delivery at the time of installation ●
Figure 3.34 Turbine Flow meter setup.
3.3 Field Installation
viii) Pressure gauges installed on both sides of the strainer monitor differential pressure across the strainer. Alternately, Pressure Differential gauges or Transmitters are also used. High pressure differential caused by filling of the basket or occlusion of foreign material can cause a strainer basket rupture, resulting in possible Turbine meter damage. Therefore, pressure gauges / other instruments are usually checked immediately after flushing or hydro test ix) The flow meter should be located as far as possible from any electrical equipment such as motors, solenoids or relays that could induce an interference signal into the Turbine meter pickoff coil. High amplitude interference introduced into the preamplifier can result in interference with the flow signal. Proper shielding and an earth grounded Local Mounted Enclosure housing will greatly reduce the possibility of induced interference x) The meter housing internal components are assembled by the factory. The components do not need to be uninstalled or reinstalled during installation and may violate guarantees and warranty xi) Do not remove the Security seals wire and security latch, as per manufacturer’s offer, which protect the integrity of the Turbine meter metrology and prevent preamplifier and pickoff tampering. The security latch prevents the removal of the local or remote mounted enclosure cover in a flameproof environment xii) While installing the electronics according to wiring and cable connections, ground the Turbine meter electronics internally for safe operation. Connect a wire to the chassis ground lug located inside the Local or Remote Mounted Enclosure as the primary ground xiii) A secondary ground, when provided by the manufacturer, is located outside of the Local or Remote Mounted Enclosure. Use the internal grounding terminal as the primary equipment ground. The external terminal is only a supplemental bonding connection where local authorities permit or require such a connection xiv) Earth ground shield at one end only, preferably at the control system end. Insulate the shield at the meter end. 3.3.7.12 Positive Displacement or PD Flow Meter
The general guidelines are common to other flow meters detailed earlier. However, some that may need specific re-mention with respect to PD flow meters are only reiterated below. a) Handling i) PD meters are heavier than most flow meters and therefore require suitable strong supporting foundations ii) Also, larger meters require fire protection measures and equipment in accordance with the local regulations, in view of resident volume within the meter iii) The PD meters must be installed to avoid potential hazards such as water hammer, vacuum collapse or uncontrolled chemical reactions iv) They are also required to be installed with suitable straining and air / gas elimination systems v) When the ambient temperature is below the minimum operating temperature specified on the device, the meter sometimes requires warm-up to an appropriate temperature before being pressurised. Necessary insulation and heat tracing shall be provided accordingly, in view of close tolerances within a meter prone to seize-up vi) PD meters also require adequate over pressure protection, and that limit pressure surge allowed to 10% of the maximum allowable working pressure of the instrument vii) Cable glands and cable must be suitable for the operating temperature of the device under its rated conditions. This is especially important as the meter has an operating temperature above 1580°F (700°C ). b) Components i) The meter generally consists of four basic components: 1) a measuring unit installed in an outer housing case; 2) the automatic pressure lubricating system unit to provide bearing and gear lubrication; 3) an adjustor for calibrating the meter; and 4) the necessary counter equipment for registering the amount of liquid throughput ii) The automatic pressure lubricating system is composed of a hydraulic cylinder, relief valve, needle valve, filling fittings and mechanical isolating seals iii) The meter may be supplied with any of several accessory items such as high frequency pulse generator, impulse contactor, automatic temperature compensator (ATC), etc. The units provide various functions for local and / or remote control and local and / or remote readout. Ensure all these accessories are properly installed as per manufacturer’s guidelines. c) Installation i) The meter should be mounted on a secure foundation or on properly designed skids. Skids are usually delivered pre-fabricated and painted. Considerations for placement of a right-angle adaptor and meter weight must be made when vertical installation is required
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ii) Care should be taken to ensure that the drain plug remains accessible. A valve may be installed on the drain line to facilitate draining of water and sediment from the meter. A lockable valve is recommended to reduce the chance of accidentally draining the meter iii) Water should not remain in the meter. If water has entered the meter, remove the inner unit and clean it with a light lubricating oil iv) As in a Turbine meter, a flow limiting valve should be installed downstream of the meter to maintain adequate back pressure and to protect the meter from excessive flow rates. There is a need to ensure that it is left closed at the time of installation of meter v) If required, an air eliminator should be installed upstream of the meter vi) Standard flow through the meter is from left to right. If right to left flow is required, consult with the manufacturer for proper design or change at site vii) The bolt pattern on the meter accessories allows the meter accessory stack to be rotated in 90° increments. The required position should be selected prior to installing the electrical service to the meter. Care should be taken not to damage the capillary tube on the temperature compensator if so equipped viii) Isolation valves should be installed on both ends of the meter run to minimise product loss when removing any of the components from the line. 3.3.7.13 Averaging Pitot Tube
i) Introduction A simple pitot tube is a Head type meter and its principle is self-explanatory in Figures 3.35 and 3.36 for measuring flow of liquid in a pipe and for air flow measurement. However, the single point solid insertion body called the Impact Pitot to measure “stagnation” pressure with a tube to measure “static” pressure is a single point measurement. Its accuracy is inadequate unless velocity in turbulent flow in the pipe or enclosed chamber, such as duct, is averaged due to the flow-velocity profile around the stagnation point/s. Accordingly, the most often used Pitot is an Averaging Pitot tube that averages the pressure at insertion point, as shown in a pipe or duct in Figure 3.36.
Figure 3.35 Pitot Tube working illustration.
Figure 3.36 Averaging Pitot Tube working illustration. Note: Found an identical figure from Internet and citation is added within graphics as shown (Omega Engineering).
3.3 Field Installation
In commercially available forms, for fluid flow in pipes, solid body design varies (round, diamond edge-shaped, etc.) as well as averaging pressure hole design. Here, the most popular pioneer instrument of averaging Pitot, the “Annubar” (manufactured by the M/S Dietrich Corporation), is only taken up for explaining the fundamentals of installation for fluid flowing in a pipe. ii) Fluid flow in Pipes a) Installation Location and Orientation 1) The Annubar is available in a variety of mounting configurations and has two methods of electronic mounting: integral mount (or direct mount) and remote mount 2) An integrally-mounted Annubar may be shipped with the transmitter already bolted directly to the sensor. If the integrally-mounted Annubar is shipped without a transmitter already attached, the I&C Contractor may be required to assemble the Annubar to the transmitter as per vendor manual guidelines. The transmitter must be calibrated to the value indicated in the Vendor Identification plate and has unique flow coefficient for the flow designed based on solid body design and Vendor tested profiles. 3) The Annubar is also available with components for welding to the pipe, Flange mounting or even with screwed fittings. Flange bolts must be tightened before applying pressure during commissioning to avoid fluid leakage. It is not allowed to loosen or remove the flange bolts while the Annubar is in service. b) General Installation Guidelines 1) Annubar installation allows for a maximum misalignment of 3° (this parameter varies between manufacturers and their models), as illustrated in below. Misalignment beyond 3° or as allowed by the manufacturers will cause errors in flow measurement. Also, for large pipes, optional side opposite end anchored support is required and the accessory is usually provided by the vendor. For in-situ retraction of the probe under pressure, a straight-through valve is provided to retract the probe. The assembly is provided with anchor rods to support the long length of the assembly and may require further tethering at site. A boss is also provided on the opposite side for support. The permitted tolerance for the angle of incline of the Annubar tube inside the pipe is 3° (max.) 2) The Annubar must be installed with adequate upstream-downstream meter runs in the pipe section to prevent measurement inaccuracies caused by flow disturbances, as per vendor user manuals but among the lowest meter run requirements among head meters. If longer lengths of straight run are available, position the Annubar where 80% of the run is upstream of the Annubar and 20% is downstream 3) Straightening vanes may be used to reduce the required straight run length and will improve performance Location of the Annubar in a pulsating flow will cause a noisy signal. Vibration can also distort the output signal and comprise the structural limits of the flow meter. Therefore, checking the mounting of the Annubar in a secured meter run as far as possible from pulsation sources such as check valves, reciprocating compressors or pumps and control valves, is important 4) Ambient temperature changes affect transmitter performance. Mounting of the transmitter to avoid vibration and mechanical shock is critical. Mounting shall also avoid external contact with corrosive materials 5) Proper venting or draining must be considered when selecting a location a) For liquid service, the side drain / vent valve is mounted upwards; this allows gases to vent b) For gas service, the drain / vent valve is mounted downwards to allow any accumulated liquid to drain c) In steam service, lines are filled with water to prevent contact of the live steam with the electronics. Condensate chambers are not needed because the volumetric displacement of the electronics is negligible. 6) Annubar instrument head connections also differ on horizontal and vertical pipes. The manufacturer’s user manual specifies proper pipe orientation for the Annubar 7) Mounting: a) Typically, in Horizontal Pipe, for Liquid or Steam Application, due to the possibility of air becoming trapped in the probe, the Annubar should be located preferably horizontally (or downwards as per manufacturer’s recommendations) b) In pits (usually water applications), the Annubar is necessarily to be mounted vertically and so venting air to avoid air-pockets frequently is common procedure c) The area between 0° and 50° (50° angle) should not be used unless full bleeding of air from the probe is possible d) In Horizontal Pipe, Air and Gas Applications, the Annubar is recommended to be located on the upper half of the pipe, at least 30° above the horizontal line e) In Vertical Pipe, for Liquid, Air, Gas and Steam Applications, the Annubar can be installed in any position around the circumference of the pipe, provided the vents are positioned properly for bleeding or venting.
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Figure 3.37 Air / Gas Pitot array.
Vertical pipe installations require more frequent bleeding or venting, depending on the location. Although Vendors recommend mounting within a sweeping angle of 80° when mounting for liquid or steam in a horizontal pipe to avoid issues with space limitations for access of transmitter, it is only decided as an exemption with approvals. For air or gas, the orientation allowed is about 60° on either side from the vertical line 8) Each Fluid service uses a different impulse piping / tubing arrangement to maintain a single phase of fluid in the piping and the Annubar transmitter. For example, liquid applications must maintain a liquid state and allow any air or gas formation to travel up and away from the Annubar transmitter, and gas applications must maintain a gaseous state and allow the formation of liquids to drain down and away from the Annubar transmitter. Remote mounting of the transmitter is required for steam installations as below. A remote mounted transmitter is connected to the sensor by means of impulse piping / tubing, especially for steam 9) Generally, a 5-valve instrument manifold is recommended for all installations. In place of a manifold, individual valves may be arranged so as to provide the necessary isolation and equalisation functions 10) As always, follow the manufacturer’s guidelines to complete transmitter wiring and other electrical / electronic requirements. iii) Air / Gas flow in Ducts Annubars used in round, square or rectangular ducts are based on “Brandt” designs of an averaging array and are specific to each manufacturer, as HVAC and installation guidelines may vary. A nozzle pitot Air or Gas Flow sensor is shown in Figure 3.37 for processing air or gas. Various versions are often used in HVAC ducts with a Pitot array for circular and rectangular ducts, as given in the American Society for Heating, Refrigerating and Air Conditioning Engineers (ASHRAE) Standards and Guidelines; and tested and calibrated in wind tunnels. Usually, the differential pressure measurement is remote using a transmitter or gauge. Leaks are the biggest problems in the measurement due to the low DP measurement and low static pressure. Often it is mounted and installed by the duct supplier for HVAC and the I&C Contractor is only required to assist in the installation and calibration of the transmitter.
3.3.8 In-Line instrumentation – Level Instruments on Vessels / Equipment 3.3.8.1 Types
The following level instruments are widely employed in industries and mainly installed on vessels, sumps, column and storage equipment, etc. They are employed as continuous level measurements or point level measurements. They are used for liquid level measurement (liquid–liquid interface (of differing densities) or liquid with vapour phase in containment) or where Solids– Other form a fluid interphase.
3.3 Field Installation
Some of them are non-intrusive and may even be considered as off-line instruments. Some of the above are also used for Solids’ level measurement in bins (e.g., Guided Wave Radar, non-contacting type Radar, Vibrating Forks, etc.). Some of these in-line level instruments are generally installed by the Mechanical Engineer in charge of Pressure Vessels or Piping discipline, under the supervision of the Instrument Engineering discipline. 3.3.8.2 General Guidelines For Installation 3.3.8.2.1 Standpipes / Stilling Well Fabrication Basics
Although rare, the fabrication and installation of still wells for level instruments (other than Boiler code vessels) are sometimes assigned to the Site Contractor and broad guidelines are therefore provided below. However, all WBS / welding procedures and NDT tests as required for a vessel shall also be performed on site as per mechanical and piping requirements, as still well is an extension of vessel with or without isolation, as per various Standards; and vessel regulations as per ASME pressure codes apply in fabrications details. Note: Regulations on standpipes are often the subject of review on site by Operations. Therefore, it is important for an I&C Contractor to be aware of the following regulations concerning use of standpipes / still wells for level instruments: i) Standpipes are generally not allowed to be used for ESD functions, but some exceptions are made when vessel / column wall shell thickness is too heavy or Boiler codes do not allow for many nozzles to allow standpipes. However, they must be curated and accepted by HAZOP analysis ii) When several instruments are required on a vessel for control and monitoring purposes, a common standpipe shall be used. The process shall be non-plugging, the tap nozzle size shall be at least 2" and the common isolation valves on the tap nozzle shall be car-sealed locked open iii) Standpipes on spheroids shall be fabricated from 6" (NPS) carbon steel pipe. Standpipes shall be supported from the spheroid shell, on cleats already welded by the mechanical fabricator iv) Standpipe connections to the spheroid shall be made by a 2" or a 3" isolating gate valve, located at the top and bottom of the standpipe, respectively. Both valves shall be in the lock-open (LO) position and car sealed v) Standpipes shall not be used on packed towers, across filter pads or demister pads, in viscous service and in applications where materials being handled contain high concentrations of solids vi) For applications, very sensitive to density change, the use of a stand pipe shall be reviewed and approved by the Customer on site too vii) When required, a dedicated standpipe shall be provided for vessel boots. The standpipe for vessel level measurement shall not be used for boot level measurement.
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3.3.8.2.2 Installation Guidelines
i) Standpipe’s / Stilling Well’s plumb line check is essential prior to mounting of Level Instruments on it ii) Threaded connections to vessels or standpipes shall be made with Type II, heavy welding bosses iii) Capability to isolate each individual instrument from the process shall be provided by an instrumentation root valve installed as close as possible to the vessel or standpipe connection (it shall be for each instrument on standpipe too). No fittings shall be allowed between this primary block valve and the connecting boss, except for a single pipe nipple. Threaded connections between the root valve and the boss shall be seal or bridge welded at site, after installation and plumb line alignment iv) Standpipes shall be hot or cold insulated when the operational temperatures ranges are either above 70°C or below 0°C. Standpipes shall not be used in low-temperature service (i.e., −7°C or below). However, insulation shall be carried out after Pre-commissioning checks by the Insulation Contractor v) When multiple gauge glass installations designed to cover long level ranges with standpipe, their weight loads should not buckle the still well at design pressure and temperature. For this purpose, guide-support and anchor support may be required on site and to be arranged by the Piping Contractor, who installs the Stillwell. 3.3.8.3 Level Gauges
The following types of level gauges are widely used in industry: 1) 2) 3) 4) 5) 6) 7)
Tubular type level gauge Reflex type level gauge Transparent type level gauge Illuminator type level gauge Electrode type level gauge Magnetic float type level gauge Torque Tube type level gauge
3.3.8.3.1 Tubular / Reflex / Transparent Level Gauge / Indicators Installation
a) Area lighting shall be provided for all gauges installed in poorly lit areas. Gauge illumination shall also be provided to all transparent gauges where readings are taken at night or are vital for safe operation of the process. Co-ordination with electrical engineers may be required for new or re-alignment of existing lighting fixtures on site b) Generally, after a hydrotest, gaskets may have to be replaced. So, it is necessary to check gauge glass gaskets (usually graphoil or graphite-impregnated type material – the gasket material must be asbestos-free and capable of sealing under continuous pressure and temperature conditions) c) Frost gauges, when provided for low temperature service below −7°C, shall extend through the gauge glass insulation. Often this requires some adjustments at site d) It is necessary to check while installing that the gauge glass is to be at the elevation required to calibrate the other blind or remote or local receiver indicator instrument e) MOC of accessories such as ball check type gauge cocks (for dirty services where waxy or gummy components exist and deposition can lead to potential blockage of the ball check flow passages) or for corrosive service shall be checked prior to installation with design data sheet f) Reflex gauges are used on all clean services, except for liquid interface level. Interface levels must have proper tags in place to identify the service g) Weld pad type reflex gauges are used in ambient temperature and atmospheric pressure applications and sometimes require welding and NDT on site by an I&C Contractor h) Sometimes in field installations, overlapping may need adjustment by adjusting Nipple length at top and bottom after disassembly and re-assembly. All test procedures have to be repeated on site after re-assembly, including NDT for welds, if applicable i) Gauge glasses, installed on the 6" spiral standpipe of spheroids are to be visible and accessible from the stairway and shall have no traps in the piping. Site coordination may be required before the stairway is fabricated for avoiding pipe traps j) Gauge glass drains shall be piped / tubed to designated closed drains and shall not be left to drain in open.
3.3 Field Installation
3.3.8.3.2 Magnetic Level Gauge / Indicators Installation
Magnetic Level Indicators (MLI) are increasingly used as an alternative to common gauge glass assemblies. MLI assemblies shall be installed only in areas that are free of physical forces or materials that would adversely affect the magnetic operation of the system, a point that is often overlooked until on site. Installation is similar to external cage displacers, and broad guidelines are given below: 1) Float will be usually shipped outside the chamber. The float is placed in the chamber and manually moved from 0% to 100% to 0% prior to start up / check out in order to re-initialise accessory products, if so equipped. Accessories may inadvertently change state due to rough handling in shipment. 2) Prior to pressure testing, float is to be removed from tank to avoid float damage. 3) The MLI name-plate can be used as bottom reference of the external cage. There is a need to check to ensure the external cage is vertical. All piping should be straight and free of “low spots” or “pockets”, so that the lower liquid connection will drain towards the external cage. Adjust piping as required. The isolation valves are left closed until start up. While opening isolation valves, a surge is to be avoided to avoid damaging the float by equalising system pressure slowly while commissioning the instrument, especially the bottom isolation valve. The drain valve be installed in the bottom flange and piped to closed drain. 4) Often MLIs are installed where fluid requires insulation after heat trace (where conventional level gauges are not easily steam traced or frost protected) but insulation or blanket must be as per the manufacturer’s recommendation. Steam Heat Tracing or Electrical Heat Tracing is usually preferred as a factory installed option. Heat traced units are generally supplied with a factory installed insulation blanket. However, if tracing is to be provided on site, it shall be installed as per tracing guidelines provided in this Handbook. Electrical heat tracing must comply to Hazardous area classification installation guidelines and therefore avoided, if possible. When MLIs are provided with heat tracing, the two most common configurations are units with a fixed-point thermostatic switch or units with an adjustable “bulb-type” thermostatic switch. With a unit with an adjustable bulb-type thermostatic switch, the temperature may be pre-set at the factory; however, field personnel should verify this setting during installation. A wiring harness, or optional junction box with terminal strip, may be required to accommodate field wiring in either case. 3.3.8.4 Guided Wave Radar (GWR)
A. Overview: Guided wave radar / Non-Contact Radar level transmitters are used for conventional continuous level measurement and rapidly replacing conventional Displacer level instruments. GWR measures both level and interface level. It can also measure each level for solids, powders and granules. It is unaffected by temperature, pressure, vapour gas mixtures, density, turbulence, bubbling / boiling, low level, varying dielectric media, pH, viscosity, etc., so has become most popular in recent times. Various probes are recommended, depending on application and available with various connection ends. The Guided Wave Radar Transmitter is a smart, two-wire continuous level transmitter based on Time Domain Reflectometry (TDR) principles. Low-power nanosecond pulses are guided along an immersed probe. When a pulse reaches the surface, part of the energy is reflected back to the transmitter, and the time difference between the generated and reflected pulse is converted into a distance, which calculates the total level or interface level. The reflectivity of the product is a key parameter for measurement performance. The reflection intensity depends on the dielectric constant of the product. Media with a high dielectric constant gives better reflection (signal amplitude) and a longer measuring range. For interface calibration, the dielectric constant of the upper product is essential for calculating the interface level. This section provides a framework for chamber and still well installations, and for transmitter installation. The basics of pipe and tank installation are also covered. Mechanical installation is one of the most critical steps of the GWR for a successful commissioning. When done correctly, the subsequent transmitter configuration will be considerably simplified. B. Installation Guidelines i) GWR instruments come with various connection details and on site an adapter may be required to be fabricated or provided to meet threaded or flanged connection for easy mounting on a tank roof. On vessel nozzles, it is by using different flanges
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Figure 3.38 GWR Mount and Level references.
ii) When mounting in non-metallic tanks and concrete silos, a metal sheet / support is used to properly hold the GWR instrument and its probe iii) There might be considerable down-pull forces on silo roofs caused by the media, so the silo roof must withstand the maximum probe tensile load iv) The tensile load depends on silo size, material density and the friction coefficient. Forces increase with the buried length, the silo and probe diameter. Depending on position, forces on probes are two to ten times greater on probes with tie-down than on probes with ballast weights and not always pre-designed, so ballast weights may be required at site (Figure 3.38) v) The instrument is sensitive to sources of electrical disturbance in proximity of the installation (e.g., electrical motors, stirrers, servo mechanisms) vi) For electrical connection best process industry practice must be followed to complete the transmitter wiring and grounding, in line with the manufacturer’s manual vii) Transition zones, located at the very top and bottom of the probes, are regions where measurement performance is reduced. Different factors affect the size of the transition zones: probe type, centring disk or no centring disk, and the material and media measured viii) The weight on the flexible probes reduces the measurement range. Therefore, it is recommended to dimension the cage so it does not interfere with the effective measurement range as in the Manufacturer’s Instruction Manual. The transition zones also limit the minimum probe length. So, while installing, calibration points of high and low level must be noted and recorded ix) Mounting in chamber / still pipe for liquids a) The chamber can be a bridle, side pipe, bypass pipe or a cage, as in displacer instruments with side-side or sidebottom connections. However, a flexible probe is not suitable due to the chance of it coming into contact with the walls, and relatively large side inlets may interfere with the signal. However, to prevent the probe from contacting the wall, centring discs are available for the rigid single, segmented rigid single, flexible single and flexible twin lead probes. The disc is attached to the end of the probe, and thus keeps the probe centred in the chamber. When mounting a centring disc, it is important that it fits correctly in the chamber / pipe. Consult the Manufacturer’s Manual for proper arrangement. b) Generally, GWR can be used in chambers to measure the level of oil, the interface of oil and water, or other liquids with significant dielectric differences and a clear interface between the two products, as in Displacer measurement. x) Flushing Connections and Vents are recommended to remove the air-gap in interface applications with fully submerged probes. A separate flushing ring may be inserted between the transmitter flange and cage flange
3.3 Field Installation
xi) Venting may be needed to manipulate the level in the cage to verify the output of the transmitter, or to drain the cage. A standard integral cage vent is provided for this purpose during pre-commissioning xii) The chamber should always be insulated in hot application to prevent personal injuries and reduce the amount of energy needed for heating. It is often an advantage, and sometimes even required, for the radar measurement ● In hot applications, insulation will reduce the amount of condensation, since it prevents the upper part of the chamber from becoming a cold spot ● Insulation prevents the product from solidifying inside the chamber and from clogging the inlet pipes. xiii) The Insulation Contractor must be advised of the requirements to insulate such chambers and verified after initial checkout of instrument but prior to pre-commissioning activity start xiv) Tank Mounting a) The GWR is installed in high-temperature applications, considering the maximum ambient temperature. Manufacturer’s recommend insulation should not exceed 4" (10 cm) above the top of the process connection on tanks b) For easy access to the transmitter, it must be mounted with sufficient service space. For maximum measurement performance, the transmitter should not be mounted close to the tank wall or near other objects in the tank. If the probe is mounted close to a wall, nozzle or other tank obstruction, noise may appear in the level signal. The Manufacturer’s recommendation must be verified for recommended space clearance c) The Guided Wave Radar transmitter is insensitive to tank shape and the shape of the tank bottom has virtually no effect on the measurement performance. The transmitter can handle flat or dish-bottom tanks. Still wells or pipes are used in many applications and in many different types of tanks to have a calmer, cleaner surface and eliminate issues with disturbing obstacles. Both Guided Wave and non-contacting Radar perform well in pipe still wells. So, often still wells are fabricated on site for small tanks, when site review requires them to provide a still well by the Client d) While locating an appropriate mounting position for the transmitter, it should not be mounted close to inlet pipes and the probe should not come in contact with the nozzle. If there is a chance that the probe may come in contact with the tank wall, nozzle or other tank obstructions, the coaxial probe is the only recommended choice e) Generally, the Radar instrument is recommended in tanks with agitators. Physical contact between probes and agitators, as well as applications with strong fluid movement, is avoided if the probe is anchored. The relevant vendor manual for anchoring options must be consulted f) If the probe is able to move 1 ft (30 cm) from any object, such as an agitator, during operation, probe tie-down is recommended. To stabilise the probe for side forces, a weight may be hung at the probe end (flexible probes only) or fix / guide the probe to the tank bottom g) For Radar instruments, even with flexible co-axial probes, bending the probe during any part of the installation is not allowed. It may be necessary to shorten the probe, mount a centring disc or anchor the probe during the mechanical installation h) In solids level applications, the following installation guidelines apply: Check for mounting near inlet pipes in order to avoid product filling on the probe required on site. Needless to add that the vessel be empty during installation. For concrete containers, the distance (L) between the probe and the wall should be at least 20" (500 mm). The probe must be stabilised for side forces, by attaching the probe to the tank bottom. Anchoring in solids containers over 30 m in height are not provided, as tensile loads are much stronger for anchored probes. Mounting close to silo walls near the probe may interfere with measurements and so should be avoided. The minimum distance from the wall is provided by the manufacturers. Generally, when a probe rope is used, the sag allowed shall not exceed 1 cm per every metre of rope length but sag is required to avoid breaks due to high tensile loads from to solids weighing down on the rope. At the bin bottom, tethering with a welded eyelet with clamps is a standard. 3.3.8.5 Non-Contact Radar Level Transmitter Installation
Non-contacting type radar instruments work on two differing technologies and installations vary based on different components or accessories that are employed based on selected technology. Pulse Radar Technology is based on measurement of distance to level surface based on short radar pulses. When a radar pulse reaches a media, part of the energy is reflected back to the Level Transmitter. Based on the time difference between the transmitted and the reflected pulse, level, volume and level rate are calculated.
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The Frequency Modulated Continuous Wave (FMCW)-method technology uses a transmitted radar signal that has a linear frequency variation of around 10 GHz. The reflection from the liquid surface has a slightly different frequency compared with the signal transmitted from the antenna when the reflection is received. The difference in frequency is directly proportional to the distance between the antenna and the liquid surface, and thereby also the liquid level. All Radar gauges measure levels based on the frequency shift technology. The device may use Frequency Modulated Continuous Wave (FMCW) or Synthesised Pulse Radar (SPR). A non-contacting radar level instrument comes with different types of antenna based on the application it employed. Antennas for LPG/LNG levels are cone type antenna for bullets, sphere and dome roof tanks, Still Pipe Array Antenna for fixed roof and internal floating roof tanks and parabolic antenna for fixed roof tanks, etc. 1) The level gauge with Horn Antenna must be installed so that there are no pipes or other obstacles that could prevent the radar beam from reaching the tank bottom unobstructed. There are two flanges available; a horizontal flange for vertical installation, and an inclined flange for installation close to the tank wall 2) Obstacles (construction bars, pipes larger than 2", etc.) within the radar beam are generally not accepted, as these may result in disturbing echoes. However, in most cases, a smooth tank wall or small objects will not have any significant influence on the radar beam. Generally, each type of antenna is specific for applications and it is important to be aware as some considerations apply to dimensions during installation (Figure 3.39). The gauge with Parabolic Antenna is designed for mounting on tanks with fixed roofs. When installing Radar instruments with parabolic antenna, the following requirements shall be addressed as per the Manufacturer’s Manual: ●
●
●
The inclination of the radar instrument with Parabolic Antenna should not exceed 1.5° (the manufacturer shall be consulted for more accurate information) towards the centre of the tank. This is done by using the Flange Ball that will aid to adjust the antenna inclination For products with high condensation such as bitumen / asphalt applications, the radar beam should be directed vertically without any inclination Radar instrument with Parabolic Antenna require several distances to be maintained as per manufacturer recommendation. The nozzle height must not exceed the manufacturer’s recommendations. There has to be a free passage for the radar beam within a 5° angle from the edge of the parabolic reflector to the lower end of the nozzle (Figure 3.40).
3) Still-pipe Array Antenna is used on tanks with still pipes, mostly with all products suited for still pipes, except Methanol, for which the other antennas are recommended. For highest performance, the total area of the slots or holes in the still pipe must not exceed the values recommended by the manufacturer, but sometimes at sites additional holes are often the requirement. Radar instruments with still-pipe array Antenna are available with both fixed version and hatch version that require different free space dimension requirements.
Figure 3.39 Radar Antenna Types and Installation.
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Figure 3.40 Radar Level Dimension considerations in Installation.
4) LPG/LNG Antenna is designed for level measurements in LPG and LNG tanks. A 4" still-pipe is used as a wave guide for the measurement. As standard, the gauge is equipped with a fire-proof block valve. A vapour space pressure sensor is also sometimes provided. A Verification Pin allows to verify measurements without opening the tank, by comparing the measured distance with the actual distance to the Verification Pin. 5) A Radar instrument with an LPG/LNG Antenna requires measurement of temperature and pressure. Therefore, it is provided with Multi-input Temperature Transmitters and Pressure Transmitters that sometimes use the same still pipe support for temperature 6) The still-pipe must be installed prior to the gauge installation and almost always the still pipe is customer supplied. In a still well, holes should be drilled on one side of the pipe. The gap between the cone-antenna and the pipe should not be larger than 2" (5 mm) 7) It should be manufactured according to the installation drawings on site by an LPG/LNG tank fabricator supervised by the I&C Contractor. The still pipe must be vertical to within ± 0.5° and the flange must be horizontal to within ± 1° and a verification pin (G) shall also be installed as recommended by the manufacturer 8) The Radar Level Gauge should be placed such that there is a minimum gap between the flange and the maximum product level. If necessary, an extension pipe can be used to raise the gauge level. This will allow measurements closer to the top of the tank than would otherwise be possible 9) A Deflection Plate is mounted at the lower end of the still pipe and is integrated with a ring that is used for calibrating the gauge during the installation phase when the tank is empty. The Deflection Plate can be attached to the still pipe by using one of three methods: Welding, screw and nut or riveting, but requires an extra ring for the Deflection Plate. Antennas with plastic surfaces and painted surfaces may under certain extreme conditions generate an ignition capable level of electrostatic charge. When installing in hazardous areas, ensure using tools, cleaning materials, etc., that cannot generate electrostatic charge. 10) The antenna and its accessories installation is completed with transmitter wiring, wireless gateway installation, remote system cabinet installation, etc., as per the manufacturer’s installation guidelines and also on manufacturer’s guidelines on electrical and grounding wiring completion. 3.3.8.6 Differential Pressure Level Instruments
The installation guidelines of any DP transmitters apply here too for level measurement using a Differential Pressure transmitter (Figure 3.41). The details are included under Section 3.3.6.
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Figure 3.41 Level DP arrangement.
a) Improper assembly of manifolds to a traditional flange can damage the sensor module. For safe assembly of manifold to traditional flange, bolts must break the back plane of the flange web (i.e., bolt hole), but must not contact sensor module housing b) Measurement accuracy depends upon proper installation of the transmitter and impulse piping. The transmitter must be mounted close to the process with minimum piping / tubing to achieve best accuracy while keeping in mind the need for easy access, personnel safety, practical field calibration and a suitable transmitter environment. The transmitter must be installed to minimise vibration, shock and temperature fluctuation c) For steam service or for applications with process temperatures greater than the limits of the transmitter, blowing through the impulse piping through the transmitter must be avoided. Flushing lines with the blocking valves closed and refilling lines with water before resuming measurement is a standard practice d) When the transmitter is mounted on its side, the coplanar flange is positioned to ensure proper venting or draining. The flange is to be mounted as shown in the instrument hook-up, keeping drain / vent connections on the bottom for gas service and on the top for liquid service e) The process flanges must be mounted with sufficient clearance for process connections. For safety reasons, the drain / vent valves are placed so that the process fluid is directed away from possible human contact when the vents are used. In addition, there is the need for a testing or calibration input f) Most transmitters are calibrated in the horizontal position. Mounting the transmitter in any other position will shift the zero point to the equivalent amount of liquid head pressure caused by the varied mounting position g) To improve field access to wiring or to better view the optional LCD display, the housing rotation set screw is loosened, and the housing is turned left or right up to a maximum of 180° from its original position. Over-rotating will damage the transmitter h) The piping between the process and the transmitter must accurately transfer the pressure to obtain accurate measurements. There are six possible sources of error: pressure transfer, leaks, friction loss (particularly if purging is used), trapped gas in a liquid line, liquid in a gas line and density variations between the legs i) The best location for the transmitter in relation to the process pipe is dependent on the process. The manufacturer provides the mounting locations and guidelines to determine transmitter location and placement of impulse piping as follows:
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j) The Integral Manifold on the sensor module is installed as per the manufacturer’s guidelines. A zero trim on the transmitter / manifold assembly is always performed after installation to eliminate any shift due to mounting effects k) The transmitter wiring and grounding are completed as per manufacturer guidelines. 3.3.8.7 Displacer Level Instruments
Displacer type level instruments utilise simple buoyancy principles to detect and convert liquid level changes into a stable output signal. The linkage between the level sensing element and output electronics provides a simple mechanical design and construction. They can be used to measure level of a liquid or interface level between two immiscible liquids. Note: Interface is defined as the boundary surface between two immiscible liquids with different specific gravities; for instance, as found in a tank containing water and petrol. The interface occurs in an intermediate zone of the displacer which must function completely submerged. The buoyancy, which determines the measurement, depends not only upon the interface level, but also on the difference in specific gravities of the liquids. Consequently, special displacer and special torque tube, if necessary, will have to be provided for interface measurement. There are two basic types of Displacers Level instruments: Linear Variable Differential Transformer (LVDT) type and Torque tube type. 3.3.8.7.1 LVDT Type Displacer Level Instruments
Electronic LVDT displacer level transmitter technology operates by detecting changes in buoyancy force caused by liquid level change. These forces act upon the spring supported displacer, causing vertical motion of the core within an LVDT. This LVDT type displacer level instrument is used to measure liquid level, interface level and liquid density. 3.3.8.7.2 Torque Tube Type Displacer Level Instruments
Torque tube liquid level instruments utilise the buoyancy exerted on a displacer when immersed in a liquid. The buoyancy on the displacer is proportional to the liquid level and operates on an elastic torque tube. This transforms the applied force in a rotary movement, operates the magnet and consequently the electronic transmitter. This system is friction-free as the torque tube also acts as a sealing device towards the pressure of the process fluid whose level is being measured. The instruments are provided with a system for the specific gravity calibration of the measured liquid. They can also be designed for the interface measurement of different liquids (or for density measurements). 3.3.8.7.3 Installation Guidelines
a) Both types are available in different styles for external or internal mounting on the tank and offer different possibilities, both for the process connection position and for the construction materials. The instruments are also available for external mounting (displacer cage type) or for top or side mounting (displacer internal to process, without cage). The mounting on the tank / vessel is achieved by means of flanged connections and the various styles such as left-arm mounted, right-arm mounted and top mounted, etc., are available. b) In the types for internal installation, the displacer connecting rod to the torque tube is factory cut to proper length. On precise installation, the displacer has to work in liquid not subjected to turbulence; otherwise, it is advisable to provide a stilling well to minimise liquid movements with particular reference to the cross forces. Naturally, the stilling well must allow the free displacer movement along its axis without frictions and permit the regular flow of the measured liquid. Its internal diameter must be 10–15 mm higher than the displacer diameter. The bottom must be open and a series of side holes are required for free liquid circulation c) During installation, all shocks or damage to the displacer and its rod must be avoided d) Displacer and displacer rod with its articulation and torque tube must be kept free from deposits and scales, which can increase the weight and introduce frictions e) For temperatures exceeding the instrument’s standard design temperature, an extension between the instrument case and the torque tube device is provided f) For the measurement of the interface level, the displacer is completely immersed and its buoyancy exerted on the float varies with the specific gravity of the liquid and independently from the level. The dimensions of the displacer depend on the measuring range of the density. It is necessary to verify at site, prior to installation, the level sketch details prior to installation, particularly for interface level
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g) The upper part of the displacer rod is provided with a friction-free ball joint for quick connection to the torque arm. In the instruments for internal mounting, the length of the rod is designed according to the process requirement. However, on site, it must be verified that there is no internal hindrance to the functioning of the instrument or forcible removal of ball joint due to liquid splashes h) The buoyancy exerted on the displacer varies with the liquid specific gravity. In order to ensure that the liquid level travelling from bottom to top of the displacer exactly corresponds to the pointer movement through the full scale of the instrument, a compensation has to be carried through the calibration of the electronic circuit by means of the magnetic tool or using the communication protocol on site, referring to the manufacturer’s instruction manual i) The parameter referred to as LEVEL_OFFSET in the transmitter setting is the desired level reading when the liquid is at the zero-reference point of the sensor On a top mounted model, the zero reference is the bottom of the displacer (not including the hook). On a side-bottom mounted model, it is the length of the level range below the centreline of the upper-side process connection. On a side-side mounted model, the zero reference is the centreline of the bottom-side process connection. j) Generally, the Manufacturer’s Calibration Certificate will provide the details necessary to confirm that the unit is shipped from the factory with Level Offset = 0. This must be checked at the time of installation and mark-up made in installation QA/QC table check k) As always, the transmitter wiring and grounding as per the manufacturer’s guidelines shall be completed. 3.3.8.8 Float Type Liquid Level Switches
Although floats are used for level measurement in the process industry, its principal use in Oil and Gas is as level switches. 3.3.8.8.1 Switch Mechanisms
a) Side mounted level switch units employ permanent magnetic forces as the only link between the float and the switching element. As the pivoted float follows liquid level changes, it moves a magnetic sleeve into or out of the field of a switch actuating magnet causing switch operation. A non-magnetic barrier tube effectively isolates the switch mechanism from the controlled liquid b) In the top mounted float switches, as in side mounted types, a permanent magnet is attached to a pivoted switch actuator and adjustment screw. As the float rises following the liquid level, it raises the attraction sleeve into the field of the magnet, actuating the switch. The enclosing tube provides a static pressure boundary between the switch mechanism and the process. On a falling level, an Inconel spring retracts the magnet, deactivating the switch c) Yet another float level switch for wide differential level applications is offered by many manufacturers, where the moving ballast causes a flipping motion of the float to provide positive switching action, even under turbulent conditions. As it is usually a low-cost solution recommended for use in either clean or dirty liquids, it is ideal for use in sump control, wet well applications and pilot systems. 3.3.8.8.2 Installation Guidelines
a) Usually, liquid level switches are shipped from the factory with the float removed from the head assembly and packed separately in the same container. Unpack the instrument carefully. As is normal with any instrument dis-assembled and shipped, it is necessary to make sure all components have been removed as per the packing material list and to inspect all components for damage b) Ensure that no tubes, rods or other obstacles in the tank or vessel could interfere with the operation of float(s) c) Before assembling control to tank or vessel, nozzle length and inside diameter must be checked and sized correctly to allow for switch actuation at design levels within the maximum differential available d) The nozzle should be checked for horizontal alignment. Finished mounting must allow control switch housing to be within 3° of vertical for proper operation. A 3° slant is noticeable by eye, but installation should be checked with a spirit level e) Switch mechanism housing must not be insulated f) All units are usually shipped from the factory with the enclosing tube tightened and the switch housing set screw locked to the enclosing tube. Failure to loosen the set screw prior to repositioning the supply and output connections may cause the enclosing tube to loosen, resulting in possible leakage of the process liquid or vapour g) The units are shipped with the cable entry of the switch housing placed 90° opposite the tank connections to simplify installation in most cases
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h) Switch housing may be rotated 360° to allow correct positioning of cable entry and set screws tightened at base of switch housing. The threads may be lubricated to facilitate easy removal i) The manufacturer’s wiring diagram shall be used to locate the switch terminals. Any wiring must be dressed to ensure no interference or contact with the switch actuation arm, or replacement of switch housing cover and are observed to be in line with all applicable electrical codes and proper wiring procedures j) Moisture seepage into the enclosure is a common issue and can be prevented by installing approved cable glands. A positive seal by gasket is necessary to prevent infiltration of moisture laden air or corrosive gasses into switch housing k) For units with explosion proof housing, the unit should not be powered until the cable gland is sealed and the enclosure cover is screwed down securely l) The switch action is tested by varying the liquid level in the tank or vessel but a dry test is done by moving the float. If the switch mechanism fails to function properly, vertical alignment of control housing may need to be adjusted and / or the switch mechanisms need to be checked m) The differential, or the amount of level travel between switch-on and switch-off, may be adjusted by repositioning the lower jam nuts on the float stem. Follow the manufacturer guidelines for adjustment procedure. 3.3.8.9 Magnetostrictive Level Transmitters
Magnetostrictive level transmitters are often combined with magnetic level indicators. The broad installation guidelines are as follows: 1) As always, after unpacking the instrument carefully and inspecting units for damage, the instrument is installed with the transmitter head mounted into the probe using the right tool provided by the manufacturer 2) These instruments use electronic components that may be damaged by static electricity present in most work environments. Manufacturers provide guidelines to protect the instrument from electrostatic discharge 3) All electrical connections are completely made and none are partial or floating. Ground all equipment to a reliable earth ground 4) As always, we have to ensure that the power to be supplied to the instrument is the same voltage (24 Vdc) as ordered with the instrument, and that the wiring between the power supply and the transmitter is correct for the type of installation 5) Mounting options are several and need to be verified as per location. Also, all of these configurations are available with one or two magnetic floats (two floats are necessary to measure total and interface level) 6) Each externally mounted transmitter is provided with a set of clamps (two or more, depending on probe length) for securing to the MLI chamber. If the transmitter was ordered with an MLI, then it will come pre-mounted, but if the transmitter was ordered separately, then it has to be secured on site with the accessories following the manufacturer’s guidelines 7) When mounting the transmitter onto the outside of an MLI, float proximity must be taken into account. For some makes and models of MLIs, the distance between the float and the chamber wall is the same all around the chamber, so the transmitter can be placed anywhere. In some makes and models of MLIs, the chamber is divided into two sections: the float section and the Magnetostrictive probe / gas-bypass section. Because of this, the transmitter must be specifically placed as close to the float section as possible, to ensure proper signal strength 8) The direct insertion version of the Magnetostrictive transmitter also has several available configurations. As with the external mount, a direction insertion Magnetostrictive transmitter is available with one or two floats. The Magnetostrictive transmitter can be installed in external chambers or into the main vessel. It is also available with a centring disc and / or stilling well to keep the probe in position. In some makes, the float is held on the probe by a C-clip inserted into a groove machined into the tip of the probe. The float is attached or removed by removing and re-inserting the C-clip. To ensure proper float orientation, the float is marked “UP”. 9) When placing floats on the probe, make sure the side marked UP is facing upwards. If there are two floats, make sure the total level float (the lighter float) is on top, and the interface float (the heavier float) is on the bottom 10) For personnel and equipment protection, external chambers have high-temperature insulation provided with transmitters. Insulation pads provide protection for the transmitter only, whereas insulation blankets cover the entire chamber, which can help protect personnel from elevated temperatures. For applications in which vibration is an issue, the transmitter is provided with a vibration absorption kit. These accessories shall be installed on site following the manufacturer’s guidelines.
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3.3.8.10 Capacitance Probe
A. Capacitance Probe Liquid Level Transmitter The principle of capacitance level measurement is based on the change in capacitance of the capacitor due to the change in the level. The probe and container wall (conductive material) form an electric capacitor. When the probe is in air, a certain low initial capacitance is measured, including some inactive length within the metal nozzle. When the container is filled, the capacitance increases as the probe is covered in 0 and 100% of the desired measurement range of liquid (Figure 3.42). At about a conductivity of 100 μS cm–1, the measurement is independent of the value for the Dielectric Constant (DK) of the liquid. As a result, fluctuations in the DK value do not affect the measured value display. Furthermore, the system also prevents the effects of medium build-up or condensate near the process connection for probes with an inactive length. A ground tube is used as a counter-electrode for containers made of nonconductive materials. The rod probe can be installed: ● ● ●
in conductive tanks made from metal in nonconductive tanks made from plastic vertically from above or below. The following installation guidelines are generally recommended:
1) The probe cannot come in contact with the metal container wall and probes should not be installed in the area of the filling curtains. If multiple probes are mounted next to each other, a minimum distance of 500 mm (19.7 in), or as recommended by the manufacturer, between the probes must be observed 2) When using in agitating tanks, make sure you install at a safe distance from the agitator 3) When mounting, ensure there is a good electrically conductive connection between the process connection and the tank. For example, use an electrically conductive sealing band. If the process connection of the probe is insulated from the metal tank using a seal material, then the ground connection on the probe housing must be connected to the tank using a short line. If the probe is installed in a plastic tank, then a probe with ground tube must be used. The probe housing must be grounded. A fully insulated rod probe may be neither shortened nor extended, as damaged insulation of the probe rod causes improper measurements.
Figure 3.42 Capacitance probe principle.
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4) Manufacturers provide application examples in the User Manual to show the vertical installation for continuous level measurement for: a) Conductive metal tank; and b) Probe with ground tube for non-conductive tanks (water storage tanks) and probes required with remote electronics 5) Make sure that the housing surface and seals are resistant to cleaning agents 6) Depending on the application, build-up of contamination or soiling can form on the probe rod. A high level of material build-up can affect the measurement result. The regular cleaning of the probe rod is recommended if the medium tends to create a high level of build-up 7) Make sure that the insulation of the probe rod is not damaged if hosing down or during mechanical cleaning 8) The maximum cable length between the probe and separate housing cannot exceed the manufacturer’s recommendation 9) As always, wiring and grounding shall be checked to be as per manufacturer’s guidelines. B. Capacitance Probe Solid Level Switch The capacitance probe solid level switch uses the principle of measuring capacitance through Radio Frequency (RF) to detect the presence or absence of a solids medium and monitors the change in capacitance between the probe and the wall of the silo or containers. The level switch detects the presence and absence of a process media at its installation point and reports it as a switched electrical output. When the solids medium in the vessel (silo) falls away from the probe level, it causes a decrease in capacitance that is detected by the electronics and the output switches to indicate an “uncovered” state. When the solids medium in the vessel (silo) rises and covers the rod, it causes an increase of capacitance that is detected by the electronics and the output switches to indicate a “covered” state. The electrical output will vary depending on the electronics selected. Installation options available are: ● ●
Rod version: vertical, horizontal and angled installation Cable version: vertical installation
The level switch can be used with all powdery and granulated bulk materials, slurry and liquids, but some installation guidelines vary according to solid level measured. 1) The level switch has a threaded, flanged or Tri Clamp process connection (usually used for food materials) for mounting it onto a silo (or another vessel). It can be mounted on a side wall of the silo, so that it is level with the filling limit to be monitored. Alternatively, if it has an extended length, it needs to be mounted vertically on top of a silo to monitor the maximum filling limit. Horizontal mounting requires cable glands to be pointed downwards to avoid water getting inside the housing. Always it is advisable to check that the level switch is not directly under the flow of solids material (filling point) 2) The length of the capacitance probe varies, based on manufacturer’s make and model. The probe may be provided with an extension tube or extension rope but usually needs to be fixed on site 3) Manufacturers recommend the use of a sliding sleeve so that the switching point can be changed easily during the live operation of the level switch 4) Before mounting the level switch on a silo (or other vessel), the safety and pre-mounting cautions on tightening with applicable torque and mechanical load are to be reviewed 5) It is advisable to grease the screws of the housing cover (lid) when a corrosive atmosphere is present 6) Active and inactive probe lengths: The active length is always inside the silo and generates an electrical field between the probe and the silo wall. With active shield technology, the RF measurements are unaffected by product build-up on the probe. The inactive length is used to extend the overall probe length. 7) Minimum distances required between installed level switches, the walls of a silo and a protective shield shall be as per Instrument Manufacturer specification. The installation of a protective angled shield above the level switch is recommended, depending on the type of bulk solids. For correct and incorrect mounting of probe, the manufacturer’s user manuals are required to be checked prior to installation. 3.3.8.11 Vibrating Fork Level Detector
Vibrating fork point level detectors are designed to use the principle of a tuning fork. A piezo-electric crystal oscillates the forks at their natural frequency, and changes to this frequency are continuously monitored by the electronics. The frequency of the vibrating fork sensor changes depending on the liquid medium in which it is immersed. The denser the liquid, the lower the frequency.
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When the level detector is used as a low-level alarm, the liquid medium in the tank or pipe drains down past the fork, causing a change of frequency that is detected by the electronics and it indicates a dry condition. When the level detector is used as a high-level alarm or for overfill detection (see Figure 3.43), the liquid medium rises in the tank or pipe, making contact with the fork which then causes the electronics to indicate a wet condition. The wet and dry conditions can be transmitted digitally as an HART® signal or as a discrete output using the analogue output: 4 and 20 mA, i.e., 4 mA = “off” and 20 mA = “on” switched output states. For most liquids, including coating, aerated liquids and slurries, the function is virtually unaffected by flow, turbulence, bubbles, foam, vibration, solid particles, build-up or properties of the liquid. The level detectors can be mounted in an open or closed tank, or a pipe. There is a wide range of threaded, flanged and hygienic process connection options. This vibrating fork type level detector can also be installed in multi-drop network mode. Each device is identified by a unique address and responds to the commands defined in the HART protocol. However, a multi-drop device in HART Revision 7 mode has a fixed analogue output of 4 mA for all but one device. Only one device is allowed to have an active analogue signal. As always, measurement accuracy is dependent upon the proper installation of the level detector. Installation guidelines are provided below: 1) Generally, improper handling has often led to instrument damage in this detector due to unfamiliarity. The fork end being very sensitive must not be altered in any way and as it is the most sensitive part, often carelessness can lead to the instrument becoming non-functional. Handling the instrument by holding the fork end is not permissible, as any distortion of the fork will result in incorrect readings 2) As always, it is required to avoid installing near to liquid entering the tank at the fill point. Avoid heavy splashing on the forks or the forks coming into contact with the tank wall, any internal fittings or obstructions, as this will lead to wrong measurements. It is important to ensure that tank crevices around the forks where liquid may collect is avoided, which can happen with high-viscosity and high-density liquids 3) Extra consideration is needed if the plant vibration is close to 1400 Hz and supporting the fork extension tube avoids long fork length vibration 4) An installation point generally missed in this type of instrument is the use of a proper seal by installing the electronics housing covers so that metal contacts metal, for reasons of grounding. The most effective grounding method for the housing is a direct connection to earth ground with minimal impedance. Housings have an external earth ground point for making this connection 5) When mounted vertically, a low-density process medium has a switching point closer to the process connection. A high-density process medium has a switching point closer to fork tip. One manufacturer’s depiction of SP: Switching point and HY: Switching point hysteresis is as shown below. This information must be verified prior to installation. Likewise, the Vendor recommends avoiding product build-up. 6) Extended forks require additional supports at installation
Figure 3.43 Vibrating fork Installations.
3.3 Field Installation
7) Installations vary for dry and wet fluids for each of the following settings: a) High and Low alarms; b) Pump control and overfill protection; and c) Pump or Empty Pipe Protection 8) Likewise, flowing fluid direction in the pipe is also critical in the orientation of fork in pipe or tank 9) However, when using vibrating fork type level switches for solid level measurement, above installation, methods may vary slightly and the Manufacturer’s recommendation must be adhered to 10) As always, instrument wiring and grounding shall also be as per the Manufacturer’s guidelines. 3.3.8.12 Rotating Paddle Level Detector
The paddle-type level switch detects the presence and absence of a process media by the stopping torque on the motor of the paddle at its installation point for all types of containers and silos, and reports it as a switched electrical output. Using a synchronous motor, the paddle (measuring vane) is driven to rotate 360°. When the vane of the paddle is not covered by a solid medium, a spring pulls the motor and switches a lug to the left position. The signal output indicates an uncovered state and the motor rotates the paddle. When a solids medium covers the vane of the paddle, and causes the rotation to stop, the lug is switched to the right position. The signal output indicates a “covered” state due to a rising level of material, and the motor is stopped until the vane becomes uncovered. The ac-voltage or dc-voltage versions of the level switch output a “covered paddle” or “uncovered paddle” status signal through SPDT relay contacts. The instrument has provisions for detecting: a) No solid level; b) Switch within solids’ level; c) Alarm position; and d) Stop motor to save instrument from damage. The level switch can be used with different paddle shapes and sizes to monitor fine and medium solids in bulk materials. Mounting is on a side wall of the silo / container. Alternatively, it can an extended length mount, allowing its installation vertically on top of a silo to monitor the maximum filling limit. Manufacturers provide a rotating paddle (vane, pendulum, etc.) and special accessories and extensions to suit the type of hopper and specific locations according to the angle of repose of solids level. Prior to installation, an accessories installation check (from inside the hopper or from outside the hopper – sliding sleeve, arm extensions, etc.) must be verified and installed. Installation guidelines of the Manufacturers are generally as follows: As always, mounting the level switch near the filling point, internal structures and walls of a silo (or another vessel) should be avoided. When mounting the extended length versions of the level switch, it is especially important to consider internal structures, as forcing the level switch into a small or congested space risks damage to the sensor and could impair the protection it provides. 3.3.8.13 Radiometric Level Detector
Basically, there are two types of radiometric level measurement based on application: Direct line and Backscatter (see Figure 3.44).
Figure 3.44 Radiometric Detector Types.
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The Gamma or Neutron source, a Caesium-137 or Cobalt-60 isotope, emits gamma / neutron radiation which is attenuated as it passes through materials. The measuring effect results from the absorption of radiation by the product to be measured caused by level changes. The measuring system consists of a source, a lead source container and a Transmitter / Detector as a receiver. Since gamma rays or neutrons are attenuated when penetrating matter, the sensor can calculate the continuous level or point level (also density or mass flow) from the intensity of the incoming radiation that is damped when penetrating the medium. The sensor detects the attenuated radiation on the opposite or same side of vessel and calculates the measured value from the intensity of the radiation. Typically, Coke drum levels use neutron back scatter, as neutrons can penetrate drum shell metal at the location of measurement effectively, but also because a neutron is attenuated and scattered by any substance containing hydrogen (e.g., water, hydrocarbons and many other industrial fluids), which makes it almost ideal for detecting the presence of many process fluids. While Cobalt-60 has a shorter half-life than Caesium-137, in multi-phase separators, the extra powerful gamma rays may be needed to penetrate the vessel or through long lengths. 1) The handling of radioactive substances is regulated by law. The radiation protection rules of the country in which the system is operated apply first and foremost. A handling permit is required for operation of a system using gamma rays. This permit is issued by the respective state government or the country’s responsible nuclear regulatory authority. 2) Safety: 2.1 When handling radioactive sources, unnecessary radiation exposure must be avoided. An unavoidable radiation exposure must be kept as low as possible. Take note of the following three important measures: a) Shielding: Provide good shielding between the source and yourself as well as all other persons. Special source containers as well as all materials with high density (e.g., lead, iron, concrete, etc.) provide effective shielding b) Time: Stay as short a time as possible in radiation exposed areas c) Distance: Your distance to the source should be as large as possible. The local dose rate of the radiation decreases in proportion to the square of the distance to the radiation source. 2.2 A radiation safety officer with the necessary expert knowledge is responsible for ensuring that the radiation protection ordinance is complied with and for implementing all radiation protection measures 2.3 Control areas are areas in which the local dose rate exceeds a certain value. Only persons who undergo official dose monitoring are allowed into these control areas. The respectively valid limit values for control areas can be found in the radiation protection ordinance. The source-shield container shields the surroundings from the radiation and only allows it to exit, practically unhindered, in the direction of measurement. To ensure the shielding effect and exclude damage to the radioactive source, all instructions in the Manufacturer’s operating instructions manual and the legal radiation protection regulations must be observed during installation and operation. Generally, the installation will be supervised by the Manufacturer’s representatives and locally assigned Nuclear Inspection Agency, but the Contractor is also required to be aware of all applicable regulations and national / international standards while using, storing and working with the radiometric measuring system. Warning instructions and safety zones are required to be marked by nuclear radiation symbols. The instrument must not be operated and stored outside the specified parameters. Obviously, the instrument must be protected against extreme influences (e.g., chemical products, weather, mechanical shock, vibration, etc.) during operation and storage. Especially when loaded with a source, the instrument may not be destroyed for any reason (e.g., for scrapping). 2.4 Before switching on the radiation, it is necessary to make sure that no persons are in the radiation area (also not outside the vessel). The radiation must only be switched on by trained personnel. If there are doubts about the proper condition of the measuring system, the radiation in the environment of the instrument is checked and reported to the responsible radiation safety officer. 2.5 Nowadays, a source container is secured by a lock system with coding known only to authorised personnel. A source container containing a gamma / neutron radioactive source has a label that identifies its specification such as isotope contained, activity, country of origin, serial number, loading date, etc. Usually, it should also be part of all records associated with storing, retrieving, installation and commissioning documents. The source holder shields the environment against gamma radiation and protects the radioactive source from mechanical damage or chemical influences. In the case of large measuring ranges (e.g., with high vessels), two or more source holders are used.
3.3 Field Installation
There are several versions available with different options for opening or blocking the beam exit. Apart from the manual versions, there is also a version with pneumatic switchover. Brackets and special mounting accessories are available for mounting the instrument. For mounting on pipelines, there are corresponding clamp brackets provided. 2.6 For mounting of source holder, as stated earlier, requires a special handling permit. Mounting may only be carried out by authorised, qualified personnel who are monitored for radiation exposure according to local laws or the handling permit. All works need to be carried out within the shortest possible time and at the largest possible distance, with suitable shielding, protections and radiation safety details in place (safety fence / zoning, etc.). All mounting and dismounting work must only be carried out with the switch in position OFF, secured with a lock and taking the weight of the source holder into account. 3) Installation 3.1 For continuous level measurement, the source holder must be mounted slightly above or at the height of the maximum level. The radiation must be directed exactly towards the detector mounted on the opposite side. The source holder should be mounted as close as possible to the vessel. However, with large measuring ranges and small vessel diameters, often a gap cannot be avoided. If there are gaps or empty spaces around the installation, provide protective fences or grids to keep hands away from the dangerous area. Such areas must be marked accordingly 3.2 For larger exit angles (40° or 60°), the beam has to be horizontal. To do this, mount the source container within the horizontal position. However, with large measuring ranges and small vessel diameters, often a gap cannot be avoided. If there are gaps or empty spaces around the installation, provide protective fences or grids to keep hands away from the dangerous area. Such areas must be marked accordingly 3.3 Also, mounting options include horizontal mounting, vertical mounting or mounting horizontally, at right-angles to the container. The cleats on the vessel are usually provided to adjust to various possibilities of mounting on site so as to bear the weight of the source holder or done on site with welded inserts in place for onward support welding by the Contractor. For reliable point level detection over the entire vessel diameter, a correspondingly long level sensor is used. In the case of bulk solids, the reaching of a limit level on a large container cross-section can be reliably detected. To do this, the largest possible beam exit angle has to be selected and the source holder rotated by 90 degrees. 3.4 After mounting, i.e., as soon as the radioactive emitter is mounted in the source holder, the local dose rate in the area of the source holder and the detector must be measured in µSv/h 3.5 Depending on the respective installation, radiation can also leak out of the beam exit channel due to scattering. Such stray radiation must be shielded off with additional lead or steel sheets. All control and off-limits areas must be rendered inaccessible and provided with warning signs 3.6 After technically correct mounting, the control area around an empty vessel must be measured for radioactivity and if there is any, the area must be cordoned off and marked. Possible ways of access to the inside of the vessel must be reliably closed off and marked with a warning sign “Radioactive” 3.7 The responsible Radiation Safety Officer can allow access after having checked the safety measures with the switched-off source holder. If work must be carried out in and on the vessel, it is absolutely necessary to switch off the radiation on the source holder. Supervised Installation control with documentation is essential while following Manufacturer’s guidelines for pneumatic switchover or manual switchover version installation 3.8 As always, the instrument wiring and grounding as per Manufacturer’s guidelines must be followed for Detectors. 3.3.8.14 Tank Gauging – Manual
Notwithstanding any form of remote measurement systems provided on large storage tanks, the Certified Dip (innage) tape is a must have for all Contractors and Companies, either for cross-checking automatic measurement of atmospheric tank level auto-gauges or for dry in-situ measurements for installation checks (see Figure 3.45). Often inspection agencies will not accept any other, except through the dip stick or hand tape through the gauge hatch on the tank. 3.3.8.15 Automatic Tank Gauging (ATG)
In a custody transfer application, a large petroleum storage tank level measuring instrument is designed with major accessories which may include the following items, as a minimum: a) Displacer-Servo / Radar / Level Transmitter or Level Gauge b) Multi-Input Temperature Transmitter for Temperature corrections.
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Reference gauge point
Gauge tape
Gauge tape
Hatch
Hatch
Reference gauge point
Reference gauge point Tape cut
Liquid level
Tank shell Reference gauge point
Outage Bob cut
Liquid level
Tank shell
Innage
Innage bob Datum plate
Innage
Outage
Figure 3.45 Tank Gauging – Hand dip (API_MPMS).
Usually for custody transfer measurements, only surface-seeking Servo or Radar, regardless of size of tank, is acceptable for ATG. Automatic Tank gauges for custody transfer shall also have an approval certificate from an independent local metrology body which is recognised by the Company and the Local Government. Hydrostatic tank gauging (HTG) is uncommon and requires pressure transmitters as an add-on, but is sometimes used as a redundant measurement in mid-size atmospheric tanks. The Radar, being most popular these days, was already discussed earlier. We now briefly discuss the other types. General principles on onshore tank installation guidelines are the same as discussed under various level measurements. API MPMS chapter 3 is the definitive guiding standard for tank gauging installation guidelines. Some common essential guidelines are listed below: .
1) Static electricity is an issue as hydrocarbon (HC) products are accumulators of static charge. A grounding on storage tanks is important for personnel safety prior to handling of instruments on the tank roof 2) Toxicity is also an issue and carefully avoiding inhaling when the tank is filled with hydrocarbons is another safety precaution 3) Any electrical gadget or testing equipment used (to include flash lights) once HC fluid is filled, shall be certified for the hazardous area and it may be good practice to follow it from the preliminary stage even when the tank is still empty. A gas certificate is required once the tank is filled with HC and emptied for human entry 4) Some installations are not suitable for Custody transfer on account of inaccuracies and should therefore be avoided for such cases as per API MPMS standards and/or Manufacturer’s guidelines, especially for Automatic Tank gauging (ATG)
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5) For custody transfer and/or inventory, the main criteria are stability with minimal vertical movement, particularly roofs, with respect to the tank reference (usually it is the datum plate or the joint where the tank shell and bottom meet) and high accuracy as required by national commercial metrology standards (typically 1 to 3 mm max is only allowed based on tank size) 6) Generally, a custody transfer gauge is never mounted without a stilling well pipe or a gauge pole 7) Any installation of the ATG shall be verifiable by manual gauging from the gauge hatch for atmospheric storage tanks 8) For pressurised storage tanks and large storage tanks, many tank conditions such as tank vapour pressure and temperature, liquid temperature, density, etc., may also apply for automatic corrections and is part of the tank management system. Installation requires checks on local conditions as well as on tank management system displays. The ATG’s level transmitter should be installed and wired in accordance with the Manufacturer’s instruction to meet the factory reference accuracy and the added uncertainty of the installation as prescribed by standards, as ATG cannot be calibrated on site, but only verified 9) Pressurised storage tank level measurements are installed so that they can be isolated from the tank (through an isolation valve or equal). Usually, a calibration chamber is provided for access to the level-sensing element 10) It is also integrated with Tank Farm Control systems, for inlet, outlet, stop / shutdown valves management and other valves and controls for product blending. I&C contractors are required to ensure proper displays on the Tank Automation System (TAS). Certain aspects of ATG installation discussed above are shown in Figure 3.46 and common to the following discussion. Gauge head
Calibration chamber + Inspection hatch
Vent valve Isolation valve Reference flange Upper hole above the maximum liquid level
Tape or wire Level detecting element L
Still pipe
Sliding guide with means to adjust verticality of still pipe
d
d
d