FOURTH EDITION 1111, I E F FOURTH EDITION Case Histories of Process Plant Disasters “Most of the incidents are very simple. No esoteric knowledge or detailed study was required to prevent them-only a knowledge of what had happened before, which this book provides.” -Treuor Kletz Learn from the mistakes of others. This invaluable and respected book examines the causes and aftermaths of numerous plant disasters-almost every one of which could have been prevented. Case histories illustrate what went wrong and why it went wrong, and then guide you in how to circumvent similar tragedies. Twenty percent of the information in this fourth edition is brand new, with fifteen new figures and photos to help you better recognize danger. Extensive references are a hallmark of this trusted volume. New sections include: Electrical isolation Heat radiation Cooling coils Recent incidents Vacuum relief valves Accidents at sea Fires Problem sources Emulsion breaking Chimney effects Interlock failure Choosing materials. Keep your plant running safely. No professional concerned with operating, maintaining, and designing process plants should be without this classic book. FOURTH EDITION WHAT WENT WRONG? FOURTH EDITION Case Histories of Process Plant Disasters Trevor KIetz Gulf Professional Publishing an imprint of Butterworth-Heinemann To Denise, Who waited while I “scorned delights and lived laborious days” but never saw the results. WHAT WENT WRONG? Case Histories of Process Plant Disasters FOURTH EDITION Copyright 0 1999 by Elsevier. All rights reserved. Printed in the United States of America. This book, or parts thereof, may not be reproduced in any form without permission of the publisher. Originally published by Gulf Publishing Company, Houston, TX 1098765 The publisher offers special discounts on bulk orders of this book. For information, please contact: Manager of Special Sales Elsevier Science 200 Wheeler Road Burlington, ,MA 01 803 Tel: 78 1-3 13-4700 Fax: 781-313-4802 For information on all Gulf publications available, contact our World Wide Web homepage at http://www.bh.com/gulf Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . , . . . I . . . xi Preface xiii Units and Nomenclature . . . . . . . . . . . . . . . . . . . . . . . . . . . xix Chapter 1. Preparation for Maintenance . . . . . . . . . . . . . . . 1 1.1 Isolation, 1 1.2 Identification, 11 1.3 Removal of hazards, 16 1.4 Procedures not followed, 24 1.5 Quality of maintenance, 32 1.6 A personal note, 44 Chapter 2. Modifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 2.1 Startup modifications, 48 2.2 Minor modifications, 49 2.3 2.4 Temporary modifications, 56 2.5 Sanctioned modifications, 58 2.6 Process modifications, 60 2.7 New tools, 63 2.8 Organizational changes, 64 2.9 Gradual changes, 66 2.10 Modification chains, 66 2.11 Modifications made to improve the environment, 69 2.12 Control of modifications, 74 Modifications made during maintenance, 55 V Chapter 3. Accidents Caused by Human Error . . . . . . . . . . 78 3.1 Introduction, 78 3.2 3.3 Accidents caused by simple slips, 79 Accidents that could be prevented by better training, 90 Chapter 4. Labeling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98 4.1 Labeling of equipment, 98 4.2 Labeling of instruments, 101 4.3 Labeling of chemicals, 104 4.4 Labels not understood. 106 Chapter 5. Storage Tanks . . . . . . . . . . . . . . . . . . . . . . . . . . . 108 5.1 Overfilling, 108 5.2 Overpressuring, 110 5.3 Sucking in, 114 5.4 Explosions, 117 5.5 Floating-roof tanks, 125 5.6 Miscellaneous incidents, 129 5.7 FRP tanks, 133 Chapter 6. Stacks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136 6.1 Stack explosions, 136 6.2 Blocked stacks, 140 6.3 Heat radiation. 142 Chapter7.Leaks 144 7.1 7.2 Control of leaks, 154 7.3 7.4 Detection of leaks, 160 7.5 Fugitive emissions, 162 Some common sources of leaks, 145 Leaks onto water, wet ground, or insulation, 159 Chapter 8. Liquefied Flammable Gases . . . . . . . . . . . . . . . . 165 8.1 Major leaks, 166 8.2 Minorleaks, 174 8.3 Otherleaks, 175 vi [...]... FOURTH EDITION 1. 1.7 14 .2.5(c) 1. 2 .1( g)-(h) 6.l(e)-(f) 6.3 1. 2.3(e) 7 .1. 2 (part) 14 .5(c>-(g) 14 .10 1. 3 .1( g) 7 .1. 3 (part) 15 .3 (part) 1. 3.3(c) 7 .1. 4 (part) 1. 4.5(d)-( e) 7 .1. 6(~)-(d) 16 .1( a),Cj ).(n) (paas) 16 .6-7 1. 4.6 7 .1. 7 17 .1 (part) 1. 5 .1( b) 7.2 .1 (part) 17 .11 -13 1. 5.7 -1. 6 7.4 (part) 18 .8-9 2.2(d)-(e) 8 .1. 6 19 .1 (part) 2.3 (end) 9 .1. 2(a) (part) 19 .5 (part) 2.6(h)-Cj) 9.2.l(g)-(i) 19 .6 2 .11 .1 (endj 9.2.2(e)... 2 .11 .1 (endj 9.2.2(e) 20 .1 (part) 3 .1 (part) 9.2.3(c) 20.4.34 3.2 .1 (part) 10 .4.5 (end) 20.5 (part) 3.2.7(b) 10 .4.6 (end) 20.6 3.3.2(c)-(d) 10 .4.7(b)-(~) 21. 2 .1 (part) 4.l(g)-Cj) 11 .1( 8) 21. 2.2 (part) 4.2(g) 4.3 .1 (part) 11 .4(d)-(e) 21. 2.6 11 .6(c) 22.2.l(d)-(e) 4.3.2 (part) 11 .9 22.2.2(d)-( e) 5.2 .1 (end) 12 .4 .1 (part) 5.4.2(d)-(f) 5.7(h) 13 .7 (part) Appendix 1 Appendix 2 14 .1( 0-(h) xviii Units and... P 1. 2 Hazardous materials introduced, 23 1 11. 3 11 .4 11 .5 11 .6 1I 7 11 .8 1I 9 Vessels not isolated from sources of danger, 233 Unauthorized entry, 236 Entry into vessels with irrespirable atmospheres 238 Rescue, 239 Analysis of vessel atmosphere, 2 41 What is a confined space?, 2 41 Every possible error, 242 Chapter 12 Hazards of Common Materials 12 .1 12.2 12 .3 12 .4 a Compressed air, 244 Water, 246 Nitrogen,... materials, 307 Chapter 17 Operating Methods 17 .1 17.2 17 .3 17 .4 17 .5 17 .6 17 .7 17 .8 17 .9 , 299 , 309 Trapped pressure, 309 Clearing choked lines, 3 11 Faulty valve positioning, 313 Responsibilities not defined, 314 Communication failures, 3 15 Work at open manholes, 318 One line, two duties, 318 Inadvertent isolation, 319 Incompatible storage, 319 viii 17 .10 .Maintenance-is it... incidents, 286 14 .10 Some accidents at sea, 287 Chapter 15 Static Electricity 15 .1 15.2 15 .3 15 .4 290 Static electricity from flowing liquids, 2 91 Static electricity from gas and water jets, 293 Static electricity from powders and plastics, 294 Static electricity from clothing, 296 Chapter 16 Materials of Construction 16 .1 16.2 16 .3 16 .4 16 .5 16 .6 16 .7 I , Wrong material... Failures 9 .1 9.2 679 Pipe failures, 17 9 Pressure vessel failures 19 5 Ghapter IO Other Equipment 10 .1 10.2 10 .3 10 .4 10 .5 10 .6 10 .7 = 205 Centrifuges, 205 Pumps, 206 Air coolers, 208 Relief valves, 209 Heat exchangers, 218 Cooling towers 2 21 Furnaces, 2 21 Chapter 11 Entry to Vessels 229 = a P 1. 1 Vessels not freed from hazardous material, 229 P 1. 2 Hazardous... necessary?, 320 17 .11 An interlock failure, 32 1 17 .12 Emulsion breaking, 322 17 .13 Chimney effects, 323 Chapter 18 Reverse Flow and Other Unforeseen Deviations 327 18 .1 Reverse flow from a product receiver or blowdown line back into the plant, 327 18 .2 Reverse flow into service mains, 329 18 .3 Reverse flow through pumps, 3 31 18.4 Reverse flow from reactors, 3 31 18.5 Reverse flow from drains, 333 18 .6 Other... Chapter 13 Tank Trucks and Cars 13 .1 13.2 13 .3 13 .4 13 .5 13 .6 13 .7 13 .8 244 262 Overfilling, 262 Burst hoses, 263 Fires and explosions, 265 Liquefied flammable gases, 266 Compressed air, 266 Tipping up, 267 Emptying into or filling from the wrong place, 268 Contact with live power lines, 270 vii Chapter 14 Testing of Trips and Other Protective Systems 272 14 .1 14.2 14 .3 14 .4... 3 31 18.4 Reverse flow from reactors, 3 31 18.5 Reverse flow from drains, 333 18 .6 Other deviations, 334 18 .7 A method for foreseeing deviations, 335 18 .8 Some pitfalls in hazop, 337 18 .9 Hazop of batch plants, 338 18 .10 Hazop of tank trucks, 340 Chapter 19 I Didn’t Know That 19 .1 19.2 19 .3 19 .4 19 .5 19 .6 343 Ammonia can explode, 343 Hydraulic pressure tests can be hazardous, 345... tons 1 kg = 2.20 lb 1, 000 kg = 1 metric tonne = 1. 10 short (U.S.) tons = 0.98 long (UK) ton Temperatures are quoted in "C xix Pressures are quoted in pounds force per square inch (psi) and also in bars As it is not usual to refer to bar gauge, I have, for example, referred to “a gauge pressure of 90 psi (6 bar),” rather than “a pressure of 90 psig.” 1 bar = 14 .50 psi = 1 atmosphere (atm) = 1 kg/cm2 = 10 0 . . . 205 10 .1 Centrifuges, 205 10 .2 Pumps, 206 10 .3 Air coolers, 208 10 .4 Relief valves, 209 10 .5 Heat exchangers, 218 10 .6 Cooling towers. 2 21 10 .7 Furnaces, 2 21 Chapter 11 . Entry. defined, 314 17 .5 Communication failures, 3 15 17 .6 Work at open manholes, 318 17 .7 One line, two duties, 318 17 .8 Inadvertent isolation, 319 17 .9 Incompatible storage, 319 viii 17 .10 .Maintenance-is. Chapter 1. Preparation for Maintenance . . . . . . . . . . . . . . . 1 1. 1 Isolation, 1 1. 2 Identification, 11 1. 3 Removal of hazards, 16 1. 4 Procedures not followed, 24 1. 5