What Went Wrong? (eBook)

Front Cover 1
What Went Wrong?: Case Histories of Process Plant Disasters 4
Copyright Page 5
Contents 6
Acknowledgments 12
Preface 14
Units and Nomenclature 20
Chapter 1. Preparation for Maintenance 26
1.1 Isolation 26
1.2 Identification 36
1.3 Removal of hazards 41
1.4 Procedures not followed 49
1.5 Quality of maintenance 57
1.6 A personal note 69
Chapter 2. Modifications 73
2.1 Startup modifications 73
2.2 Minor modifications 74
2.3 Modifications made during maintenance 80
2.4 Temporary modifications 81
2.5 Sanctioned modifications 83
2.6 Process modifications 85
2.7 New tools 88
2.8 Organizational changes 89
2.9 Gradual changes 91
2.10 Modification chains 91
2.11 Modifications made to improve the environment 94
2.12 Control of modifications 99
Chapter 3. Accidents Caused by Human Error 103
3.1 Introduction 103
3.2 Accidents caused by simple slips 104
3.3 Accidents that could be prevented by better training 115
Chapter 4. Labeling 123
4.1 Labeling of equipment 123
4.2 Labeling of instruments 126
4.3 Labeling of chemicals 129
4.4 Labels not understood 131
Chapter 5. Storage Tanks 133
5.1 Overfilling 133
5.2 Overpressuring 135
5.3 Sucking in 139
5.4 Explosions 142
5.5 Floating-roof tanks 150
5.6 Miscellaneous incidents 154
5.7 FRP tanks 158
Chapter 6. Stacks 161
6.1 Stack explosions 161
6.2 Blocked stacks 165
6.3 Heat radiation 167
Chapter 7. Leaks 169
7.1 Some common sources of leaks 170
7.2 Control of leaks 179
7.3 Leaks onto water, wet ground, or insulation 184
7.4 Detection of leaks 185
7.5 Fugitive emissions 187
Chapter 8. Liquefied Flammable Gases 190
8.1 Major leaks 191
8.2 Minor leaks 199
8.3 Other leaks 200
Chapter 9. Pipe and Vessel Failures 204
9.1 Pipe failures 204
9.2 Pressure vessel failures 220
Chapter 10. Other Equipment 230
10.1 Centrifuges 230
10.2 Pumps 231
10.3 Air coolers 233
10.4 Relief valves 234
10.5 Heat exchangers 243
10.6 Cooling towers 246
10.7 Furnaces 246
Chapter 11. Entry to Vessels 254
11.1 Vessels not freed from hazardous material 254
11.2 Hazardous materials introduced 256
11.3 Vessels not isolated from sources of danger 258
11.4 Unauthorized entry 261
11.5 Entry into vessels with irrespirable atmospheres 263
11.6 Rescue 264
11.7 Analysis of vessel atmosphere 266
11.8 What is a confined space? 266
11.9 Every possible error 267
Chapter 12. Hazards of Common Materials 269
12.1 Compressed air 269
12.2 Water 271
12.3 Nitrogen 273
12.4 Heavy oils (including heat transfer oils) 280
Chapter 13. Tank Trucks and Cars 287
13.1 Overfilling 287
13.2 Burst hoses 288
13.3 Fires and explosions 290
13.4 Liquefied flammable gases 291
13.5 Compressed air 291
13.6 Tipping up 292
13.7 Emptying into or filling from the wrong place 293
13.8 Contact with live power lines 295
Chapter 14. Testing of Trips and Other Protective Systems 297
14.1 Testing should be thorough 297
14.2 All protective equipment should be tested 300
14.3 Testing can be overdone 304
14.4 Protective systems should not reset themselves 304
14.5 Trips should not be disarmed without authorization 306
14.6 Instruments should measure directly what we need to know 309
14.7 Trips are for emergencies, not for routine use 310
14.8 Tests may find faults 311
14.9 Some miscellaneous incidents 311
14.10 Some accidents at sea 312
Chapter 15. Static Electricity 315
15.1 Static electricity from flowing liquids 316
15.2 Static electricity from gas and water jets 318
15.3 Static electricity from powders and plastics 319
15.4 Static electricity from clothing 321
Chapter 16. Materials of Construction 324
16.1 Wrong material used 324
16.2 Hydrogen produced by corrosion 328
16.3 Other effects of corrosion 330
16.4 Loss of protective coatings 330
16.5 Some other incidents caused by corrosion 331
16.6 Fires 331
16.7 Choosing materials 332
Chapter 17. Operating Method 334
17.1 Trapped pressure 334
17.2 Clearing choked lines 336
17.3 Faulty valve positioning 338
17.4 Responsibilities not defined 339
17.5 Communication failures 340
17.6 Work at open manholes 343
17.7 One line, two duties 343
17.8 Inadvertent isolation 344
17.9 Incompatible storage 344
17.10 Maintenance—is it really necessary? 345
17.11 An interlock failure 346
17.12 Emulsion breaking 347
17.13 Chimney effects 348
Chapter 18. Reverse Flow and Other Unforeseen Deviations 352
18.1 Reverse flow from a product receiver or blowdown line back into the plant 352
18.2 Reverse flow into service mains 354
18.3 Reverse flow through pumps 356
18.4 Reverse flow from reactors 356
18.5 Reverse flow from drains 358
18.6 Other deviations 359
18.7 A method for foreseeing deviations 360
18.8 Some pitfalls in hazop 362
18.9 Hazop of batch plants 363
18.10 Hazop of tank trucks 365
Chapter 19. I Didn't Know That 368
19.1 Ammonia can explode 368
19.2 Hydraulic pressure tests can be hazardous 370
19.3 Diesel engines can ignite leaks 371
19.4 Carbon dioxide can ignite a flammable mixture 373
19.5 Mists can explode 373
19.6 The source of the problem lay elsewhere 375
Chapter 20. Problems with Computer Control 378
20.1 Hardware and software faults 378
20.2 Treating the computer as a black box 379
20.3 Misjudging the way operators will respond 384
20.4 Other problems 385
20.5 Unauthorized interference 387
20.6 New applications 388
20.7 Conclusions 390
Chapter 21. Inherently Safer Design 392
21.1 Bhopal 393
21.2 Other examples of inherently safer design 397
21.3 User-friendly design 402
Chapter 22. Reactions—Planned and Unplanned 405
22.1 Lack of knowledge 406
22.2 Poor mixing 408
22.3 Contamination 410
22.4 Reactions with auxiliary materials 412
22.5 Poor training or procedures 412
22.6 Use-by dates 413
Appendix 1. Relative Frequencies of Incidents 417
Appendix 2. Final Thoughts 420
Appendix 3. Recommended Reading 422
Index 424