Chemical Process Safety (eBook)

Cover 1
Contents 6
Preface 12
Acknowledgments 13
1. Perspective, Perspective, Perspective 16
Introduction 16
The Media Rarely Focuses on the Benefits of the Chemical Industry 16
A Glance at the History of Chemical Manufacturing before the Industrial Revolution 17
The Modern Industrial Chemical Industry Modifies Our Way of Living 18
Risks Are Not Necessarily How They Are Perceived 19
Plant Employee Safety versus Life-style Choices 23
The Chemical Industry’s Excellent Safety Record 23
Who Has the Most Dangerous Jobs? 24
Just How Dangerous Is It to Work in a U.S. Chemical Plant? 30
Just How Dangerous Is It to Work in a Chemical Plant in the United Kingdom? 31
Fatal Risks Data for Various Activities in the United Kingdom 32
How Are the Chemical and Refinery Industries Doing when It Comes to Major Losses? 33
2. Good Intentions 38
Modifications Made with Good Intentions 38
A Tank Truck Catastrophically Fails 38
Siphoning Destroys a Tender Tank 42
Tank Roof Splits from Overfilling 46
A Well-Intended Change Yields a Storage Tank Collapse 47
A Water Drain Line Is Altered and a Reactor Explodes 51
An Air System Is Improved and a Vessel Blows Up 54
A New Air System Improved Economics, but Jeopardized Safety 56
Another Incident with Nitrogen Backup for a Compressed Air Supply 57
The Hazards of Nitrogen Asphyxiation 59
Concerns for Safety on a Refrigerated Ethylene Tank 60
Beware of Impurities, Stabilizers, or Substitute Chemicals 62
Good Intentions on Certain New Protection Systems Lead to Troubles 63
A Gas Compressor Is Protected from Dirt, But the Plant Catches Fire 64
The Lighter Side 64
Another Good Intentions Project: New Tank Are Destroyed and the Neighborhood is Disrupted 64
Another Tragic Incident Involving Hydrogen Sulfide Takes the Lives of Two Workers 70
Closing Thoughts on Sewers 70
A Review of Good Intentions 70
3. Focusing on Water and Steam: The Ever-Present and Sometimes Evil Twins 72
A Hydrotest Goes Awry 73
A Flooded Column Collapses as Water Is Being Drained from the System 77
Water Reacting with Strong Chemicals 79
Easy-to-Use Steam Heat Can Push Equipment beyond Safe Design Limits 81
Heating Water in a Confined System 82
Steam Condenses and a Mega-Vessel Is Destroyed During Commissioning 84
A Tragedy Develops When Hot Oil Is Pumped upon a Layer of Water 87
4. Preparation for Maintenance 92
Some Problems When Preparing for Maintenance 92
A Tank Vent Is Routed to a Water-Filled Drum to “Avoid” Problems 92
Preparing to Paint Large Tanks 94
Preparing a Brine Sludge Dissolving System for Maintenance 94
What Happened in the Brine System? 95
A Violent Eruption from a Tank Being Prepared for Maintenance 97
An Explosion While Preparing to Replace a Valve in an Ice Cream Plant 98
A Chemical Cleaning Operation Kills Sparrows, But Improves Procedures 101
Other Cleaning, Washing, Steaming, and Purging Operations 102
A Tragedy When Preparing for Valve Maintenance 102
A Review of Changes Made to Prepare for Maintenance 104
5. Maintenance-Induced Accidents and Process Piping Problems 106
Planning and Communication 107
Filter Cartridges Are Replaced and an Iron-in-Chlorine Fire Develops 107
Repairs to a Pipeline Result in Another Iron-in-Chlorine Fire 107
Repaired Reboiler Passes the Hydrotest and Later Creates a Fire 108
A Tank Explodes during Welding Repairs after Passing a Flammable Gas Test 109
A Phenol Tank’s Roof Lifts as Repairs are made 110
Catastrophic Failures of Storage Tanks as Reported by the Environmental Protection Agency 111
Repair Activity to a Piping Spool Results in a Massive Leak from a Sphere 112
The Phillips 66 Incident: Tragedy in Pasadena, Texas 113
A Massive Fire, BLEVEs, and $5 Million Damages after a Mechanic Improperly Removes a Valve Actuator 117
Misdirected Precautions on a Reactor System Isolation Plug Valve Result in a Vapor Cloud Explosion 121
A Breathing Air System on a Compressed Air Main Is Repaired 122
A Hidden Blind Surprises the Operators 123
Poor Judgment by Mechanics Allowed a Bad Steam Leak to Result in a Minor Explosion 127
The Flixborough Disaster and the Lessons We Should Never Forget 128
Do Piping Systems Contribute to Major Accidents? 130
Specific Piping System Problems Reported as Major Incidents 132
OSHA Citations 133
Four Case Histories of Catastrophic Pipe Failures 134
Piping Problems Review 136
Concluding Thoughts on Maintenance-Induced Accidents and Process Piping Problems 136
6. One-Minute Modifications: Small Quick Changes in a Plant Can Create Bad Memories 140
Explosion Occurs after an Analyzer Is Repaired 140
Just a Little of the Wrong Lubricant 140
When Cooling Methods Were Changed, a Tragedy Occurred 141
Instrument Air Backup Is Disconnected 141
An Operator Modifies the Instrumentation to Handle an Aggravating Alarm 142
A Furnace Temperature Safeguard Is Altered 142
The Wrong Gasket Material Creates Icicles in the Summer 146
Another Costly Gasket Error 146
As Compressed Asbestos Gaskets Are Phased Out, Other Leaks Will Occur 149
Other Piping Gasket Substitution Problems 150
New Stud Bolts Fail Unexpectedly 151
Hurricane Procedures Are Improperly Applied to a Tank Conservation Vent Lid 151
Painters Create Troubles 154
Pipefitters Can Create Troubles When Reinstalling Relief Valves 154
Another Pipefitter’s Error 155
A Cooling Water System Is Safeguarded and an Explosion Occurs Some Months Later 155
Lack of Respect for an Open Vent as a Vacuum-Relief Device Results in a Partial Tank Collapse 156
A Bucket of Water Destroys a Tank 157
Lack of Respect for an Open Vent as a Pressure-Relief Device Costs Two Lives 159
One-Minute Modifications Review 160
7. Accidents Involving Compressors, Hoses, and Pumps 162
Reciprocating Compressors 162
A Piece of Compressor Water Jacket is Launched 163
The Misuse of Hoses Can Quickly Create Problems 165
Some of the Many Unpublished Errors Created with Hoses 166
The Water Hose at the Flixborough Disaster 167
Hoses Used to Warm Equipment 168
Three-Mile Island Incident Involved a Hose 168
The Bhopal Tragedy Was Initiated by Use of a Hose 168
Improper Purge Hose Set Up for Maintenance Creates Major Problems 169
High-Pressure Hydrogen Inadvertently Backs Into the Nitrogen System and an Explosion Occurs 172
A Nitric Acid Delivery to the Wrong Tank Makes Front-Page News 173
How Do You Prevent Such an Incident? 173
Other Truck Delivery Incidents 174
An Operator Averts a Sulfuric Acid Unloading Tragedy 174
Hoses Cannot Take Excessive Abuse 174
Centrifugal Pumps 177
River Water Pump Piping Explodes 177
A Severe Pump Explosion Surprises Employees 183
A Large Condensate Pump Explodes 185
8. Failure to Use, Consult, or Understand Specifications 188
Failure to Provide Operating Instructions Cost $100,000 in Property Damages 188
Other Thoughts on Furnaces 191
Low-Pressure Tank Fabrication Specifications Were Not Followed 191
Explosion Relief for Low-Pressure Tanks 191
Tinkering with Pressured Vessel Closure Bolts Ends with a Harmless Bang 193
Piping Specifications Were Not Utilized 195
Pump Repairs Potentially Endanger the Plant, but Are Corrected in Time to Prevent Newspaper Headlines 200
Plastic Pumps Installed to Pump Flammable Liquids 201
Weak Walls Wanted—But Alternate Attachments Contributed to the Damage 202
An Explosion Could Have Been Avoided If Gasket Specifications Were Utilized 202
Surprises within Packaged Units 203
9. Imagine IfŽ Modifications and Practical Problem Solving 206
“Imagine If” Modifications—Let Us Not Exaggerate the Dangers as We Perform Safety Studies 206
New Fire-Fighting Agent Meets Opposition—“Could Kill Men as Well as Fires” 206
A Process Safety Management Quiz 207
New Fiber Production Methods Questioned 209
Practical Problem Solving 210
The Physics Student and His Mischievous Methods 211
10. The Role of Mechanical Integrity in Chemical Process Safety 214
Mechanical Integrity in a Chemical Plant 214
A Regulatory View of Mechanical Integrity 215
Mechanical Integrity Programs Must Be Tailored to the Specific Site 216
Mechanical Integrity in Design and Installation 216
Equipment Covered by Mechanical Integrity 216
Regulatory Enforcement of Mechanical Integrity 218
An Industry View of Mechanical Integrity 218
Written Procedures and Training 219
Classification of Equipment by Hazard Potential 219
Mechanical Integrity Programs for Pumps/Compressors 220
Thermography Techniques for Rotating and Stationary Equipment 227
Mechanical Integrity Programs for Piping, Pressure Vessels, Storage Tanks, and Process Piping 228
Inspecting Pressure Vessels, Storage Tanks, and Piping 231
Inspection of Pressure Vessels and Storage Tanks 231
Inspection of Above-Ground Piping 242
Mechanical Programs for Safety-Critical Instruments and Safety Relief Valves 243
The Critical Role of Safety Relief Valves 244
“In-House” Testing Safety Relief Valves 245
Mechanical Integrity Program for Process Safety Interlocks and Alarms 253
Protective Process Safety Interlocks at a DuPont Plant 253
Another Company—A Different Emphasis on Safety Critical Instrument Systems 254
Another Approach—Prooftesting at a Louisiana Plant 255
Additional Information on Mechanical Integrity 263
11. Effectively Managing Change within the Chemical Industry 266
Introduction 266
Preliminary Thoughts on Managing Change 266
Are Management of Change Systems Like Snowflakes? 267
A Reality Check Provided by Previous Chapters 268
Keeping MOC Systems Simple 268
Losing Tribal Knowledge 269
Some Historical Approaches to Plant Changes 269
The U.S. OSHA Process Safety Management Standard Addresses “Management of Change” 269
Principles of an Effective Management of Change System That Prevents Uncontrolled Change and Satisfies OSHA 271
An Overall Process Description to Create or Improve a Management of Change System 272
Clear Definitions Are Imperative 273
Key Steps for an Effective Management of Change System for a Medium or Large Organization 275
Key Steps for an Effective Management of Change System for a Small Company 281
Multidisciplined Committee Can Provide an In-Depth Look When Identifying Hazards 283
Operational Variances for Maintenance Need A Close Examination Too 284
Variances, Exceptions, and Special Cases of Change 285
Should the MOC System be Paperless? 287
Over Two Dozen Plants Share Their MOC Practices 288
Management of Change Approvals, Documentation, and Auditing 290
Closing Thoughts on a Management of Change Policy 291
Appendix A 292
Some Historical Approaches to Plant Changes 292
How Are Chemical Plants Addressing Plant Modifications during the 1980s and Beyond? 293
The Center for Chemical Process Safety 295
New Recommendations and New Regulations 295
Appendix B 297
How Should Potential Hazards Be Identified and Evaluated? 297
12. Investigating and Sharing Near Misses and Unfortunate Incidents 302
Introduction 302
What Does the Regulation Say about Incident Investigations? 303
Plant Cultures Can Affect Investigations 304
More Guidelines on the Culture of Incident Reporting 305
An OSHA Program Coordinator’s View 307
Layers of Incident Causes 307
A Furnace Tube Failure Case History is Revised 307
Process Safety Incident Investigation Techniques 309
Applying Root Cause Analysis 310
Some Chemical Manufacturers’ Approaches to Incident Investigation 310
What Is a Root Cause? 312
Some Thoughts on Process Safety Incident Investigation Techniques 312
Complying with the OSHA Element on Incident Investigation 312
Report Approval, Report Distribution, Sharing the Findings, Corrective Action Tracking, and Report Retention 316
Conclusions 317
Appendix A Interviewing Tips 318
General Concepts and Preplanning 318
Opening the Interview 318
Conducting the Interview 318
Closing the Interview and Documenting It 318
13. Sources of Helpful Information for Chemical Process Safety 320
The Best Seven Books in Chemical Process Safety—From a Process Engineer’s Viewpoint 322
General Chemical Process Safety Books 325
Practical Information on Safety Critical Instruments and Pressure Vessels, Tanks, and Piping 327
Other Helpful Resources 328
INDEX 334