Guidelines for Engineering Design for Process Safety CENTER FOR CHEMICAL PROCESS SAFETY of the AMERICAN INSTITUTE OF CHEMICAL ENGINEERS 345 East 47th Street, New York, New York 10017 Copyright O 1993 American Institute of Chemical Engineers 345 East 47th Street New York, New York 10017 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 without the prior permission of the copyright owner. Library of Congress Cataloging-in Publication Data Guidelines for engineering design for process safety p. cm. Includes bibliographical references and index. ISBN 0-8169-0565-7 1. Chemical engineering—Safety measures I. American Institute of Chemical Engineers. Center for Chemical Process Safety. TP155.5.G765 1993 66(T .2804—dc20 93-3154 CIP This book is available at a special discount when ordered in bulk quantities. For information, contact the Center for Chemical Process Safety at the address shown above. It is sincerely hoped that the information presented in this volume will lead to an even more impressive safety record for the entire industry; however, neither the American Institute of Chemical Engineers, its consultants, CCPS and/or its sponsors, its subcommittee members, their employers, nor their employers' officers and directors warrant or represent, expressly or implied, the correctness or accuracy of the content of the information presented in this conference, nor can they accept liability or responsibility whatsoever for the consequences of its use or misuse by anyone. v This page has been reformatted by Knovel to provide easier navigation. Contents List of Tables xi List of Figures xiii Preface xvii Glossary xxi Acronyms and Abbreviations xxix 1. Introduction 1 1.1 Objective 1 1.2 Scope 1 1.3 Applicability 2 1.4 Organization of This Book 2 1.5 References 4 2. Inherently Safer Plants 5 2.1 Introduction 5 2.2 Intensification 11 2.3 Substitution 17 2.4 Attenuation 21 2.5 Limitation of Effects 29 2.6 Simplification and Error Tolerance 37 2.7 Inherent Safety Checklist 40 vi Contents This page has been reformatted by Knovel to provide easier navigation. 2.8 Summary - A Fable 42 Appendix 2A Inherent Process Safety Checklist 44 2.9 References 47 3. Plant Design 53 3.1 Process Safety Review through the Life of the Plant 54 3.2 Process Design 56 3.3 Site Selection and Evaluation 63 3.4 Plant Layout and Plot Plan 66 3.5 Civil Engineering Design 75 3.6 Structural Engineering Design 80 3.7 Architectural Design 86 3.8 Plant Utilities 88 3.9 Plant Modifications 97 3.10 References 97 4. Equipment Design 101 4.1 Introduction 101 4.2 Loading and Unloading Facilities 101 4.3 Material Storage 106 4.4 Process Equipment 117 4.5 References 150 5. Materials Selection 157 5.1 Introduction 157 5.2 Corrosion 162 5.3 Design Considerations 168 5.4 Fabrication and Installation 169 5.5 Corrosion Monitoring and Control Techniques 170 5.6 References 175 Contents vii This page has been reformatted by Knovel to provide easier navigation. 6. Piping Systems 179 6.1 Introduction 179 6.2 Detailed Specification 180 6.3 Specifying Valves to Increase Process Safety 187 6.4 Joints and Flanges 190 6.5 Support and Flexibility 192 6.6 Vibration 197 6.7 Special Cases 199 Appendix 6A: Examples of Safety Design Concerns 202 6.8 References 205 7. Heat Transfer Fluid Systems 211 7.1 Introduction 211 7.2 General Description of Heat Transfer Fluids 212 7.3 System Design Considerations 219 7.4 Heat Transfer Fluid System Components 223 7.5 Safety Issues 230 7.6 References 234 8. Thermal Insulation 237 8.1 Properties of Thermal Insulation 237 8.2 Selection of Insulation System Materials 241 8.3 Corrosion under Wet Thermal Insulation 242 8.4 References 247 9. Process Monitoring and Control 251 9.1 Introduction 251 9.2 Instrumentation 252 9.3 Process Monitoring Using Computer-Based Systems 262 9.4 Alarm Systems Philosophy 273 viii Contents This page has been reformatted by Knovel to provide easier navigation. 9.5 Safety System Maintenance Testing 273 9.6 Implementing the Process Control System 275 9.7 Summary 290 Appendix 9A Safety Considerations for Monitoring and Control 291 Appendix 9B Instrumentation and Control Checklist 293 9.8 References 294 10. Documentation 299 10.1 Design 300 10.2 Operations 303 10.3 Maintenance 305 10.4 Records Management 309 Appendix 10A: Typical Inspection Points and Procedures 311 10.5 References 313 11. Sources of Ignition 317 11.1 Introduction 317 11.2 Types of Ignition Source 318 11.3 Ignition by Flames 318 11.4 Spontaneous Ignition (Autoignition) 321 11.5 Electrical Sources 326 11.6 Physical Sources 334 11.7 Chemical Reactions 337 11.8 Design Alternatives 342 11.9 References 343 12. Electrical System Hazards 349 12.1 Electrical Equipment Hazards 349 12.2 Lightning Protection 354 Contents ix This page has been reformatted by Knovel to provide easier navigation. 12.3 Bonding and Grounding 360 12.4 References 367 13. Deflagration and Detonation Flame Arresters 371 13.1 Definitions and Explanations of Terms 371 13.2 Introduction 375 13.3 Types of Flame Arresters 380 13.4 Regulatory Use, Testing and Certification 386 13.5 Application Considerations 396 13.6 Special Applications and Alternatives 401 13.7 Conclusions 403 13.8 Future Developments 404 13.9 References 405 14. Pressure Relief Systems 409 14.1 Introduction 409 14.2 Relief Design Scenarios 410 14.3 Pressure Relief Devices 420 14.4 Sizing of Pressure Relief Systems 428 14.5 Design of Relief Devices: Other Considerations 430 14.6 DIERS Methods of Overpressure Protection for Two- Phase Flows 431 14.7 Emergency Depressuring 440 14.8 References 441 15. Effluent Disposal Systems 445 15.1 Flare Systems 446 15.2 Blowdown Systems 465 15.3 Incineration Systems 470 15.4 Vapor Control Systems 482 15.5 References 486 x Contents This page has been reformatted by Knovel to provide easier navigation. 16. Fire Protection 489 16.1 Introduction 489 16.2 Detection and Alarm Systems 491 16.3 Water-Based Fire Protection Systems 497 16.4 Chemical and Special Agent Extinguishing Systems 502 16.5 Passive Fire Protection 507 16.6 References 515 17. Explosion Protection 521 17.1 Introduction 521 17.2 Energy Release on Noncombustive Vessel Rupture 521 17.3 Flammability 523 17.4 Flame Events 530 17.5 Flammability Control Measures Inside Equipment 538 17.6 Flame Mitigation Inside Equipment 540 17.7 References 554 Index 557 LIST OF TABLES Table 2-1 Examples of Process Risk Management Strategies 7 Table 2-2 Effect of Size on Overpressure Due to Vessel Rupture 12 Table 2-3 Effect of Reactor Design on Size and Productivity for a Gas-Liquid Reaction 14 Table 2-4 Effect of Various Options to Reduce Inventory on the Hazard Zone Resulting from the Rupture of a 500-Foot Chlorine Transfer Pipe 16 Table 2-5 Surface Compactness of Heat Exchangers 17 Table 2-6 Some Examples of Solvent Substitutions 20 Table 2-7 Vapor Pressure of Aqueous Ammonia and Monomethylamine Solutions 22 Table 2-8 Atmospheric Pressure Boiling Point of Selected Hazardous Materials 24 Table 3-1 Typical Hazard Evaluation Objectives at Different Stages of a Process Lifetime 55 Table 3-2 Typical Material Characteristics 57 Table 3-3 Selected Primary Data Sources for Toxic Exposure Limits 61 Table 3-4 Methods to Limit Inventory 63 Table 3-5 Some Important Safety Considerations in Plant Siting 64 Table 3-6 Important Safety Factors in Plant Layout 67 Table 3-7 Inter-unit Spacing Requirements for Oil and Chemical Plants 70 Table 3-8 Inter-unit [Equipment] Spacing Requirements for Oil and Chemical Plants 72 Table 3-9 Storage Tank Spacing Requirements for Oil and Chemical Plants 74 Table 3-10 1990 Loss Report 82 Table 3-11 Possible Utility Failures and Equipment Affected 89 Table 4-1 Common Causes of Loss Containment for Different Process Equipment 119 Table 4-2 Basic Considerations for All Fired Equipment 132 Table 4-3 Process Vessels: Special Material Concerns 136 Table 4-4 Checklist for Design and Operation of Activated Carbon Adsorbers 149 Table 5-1 Metal Failure Frequency for Various Forms of Corrosion 163 Table 5-2 Corrosion Inhibitors 172 Table 7-1 Typical Industrial Uses of Heat Transfer Fluids 212 Table 7-2 Commercially Available Heat Transfer Fluids 213 Table 7-3 Factors in Design of Heat Transfer Fluid Systems 220 Table 7-4 Analysis of Heat Transfer Fluids 221 Table 8-1 Design Practices to Reduce Corrosion Under Insulation 245 Table 9-1 Ranking of Process Operability and Process Safety 259 Table 9-2 Characterization of Process Sensitivity and Process Hazard 260 Table 9-3 Comparison of Instrument Type Features 261 Table 9-4 Process Control Terminology 264 Table 10-1 Elements of Chemical Process Safety Management 299 Table 10-2 Typical Design Documents 301 Table 10-3 Typical Nondestructive Examination Techniques 307 Table 12-1 Typical Hazardous Locations 350 Table 12-2 NEMA Definitions of Enclosures 352 Table 13-1 Deflagration Flame Arrester Test Standards 389 Table 13-2 Detonation Flame Arrester Test Standards 390 Table 13-3IMO and USCG Endurance Burn Requirements 392 Table 13-4 Comparison of Published MESG Values 394 Table 14-1 Advantages and Disadvantages of Pilot Operated Valves 424 Table 14-2 Advantages and Disadvantages of Rupture Disks 426 Table 14-3 Vessel Flow Models 433 Table 14-4 Summary of SAFIRE Emergency Relief System Input Data Requirements 438 Table 15-1 Incineration System Components 472 Table 17-1 Gases Supporting Decomposition Flames 526 Table 17-2 Fundamental Burning Velocity of Selected Hydrocarbons in Air 531 Table 17-3 Properties of Shock Fronts in Air 534 Table 17-4 Detonation Characteristics of Select Stoichiometric Gas-Air Mixtures 535 Table 17-5 Combustible-Dependent Constants for Low-Strength Enclosures 552 [...]... on the design team, the process hazard analysis team, and the people who make the basic decisions on plant design Engineering design for process safety should be considered within the framework of a comprehensive process safety management program as described in Plant Guidelines for Technical Management of Chemical Process Safety (CCPS 1992) These Guidelines are intended to be applicable to the design. .. catastrophic accident, starting with the initial selection of the process and continuing through its final design This book is concerned with engineering design for process safety It does not focus on operations, maintenance, transportation, storage or personnel safety issues, although improved process safety can benefit each area Detailed engineering designs are outside the scope of the work, but the authors... literature to assist the designer who wishes to go beyond safety design philosophy to the specifics of a particular design The book has been organized so as to treat basic design issues first The first design question addressed is the issue of "Inherently Safer Plants." This reflects the authors' strong belief that the optimum way to achieve process safety is to design safety into the initial design The latter... education programs for engineers; • advancing the state-of-the-art in engineering practices and technical management through research in prevention and mitigation of catastrophic events; and • developing and encouraging the use of undergraduate education curricula which will improve the safety knowledge and consciousness of engineers The current book, Guidelines for Engineering Design for Process Safety, is... hygiene practices Emergency response Detailed design Operations and maintenance These Guidelines highlight safety issues in design choices For example, Chapter 12, Electrical Hazards, covers the safe application of electrical apparatus and the reliability of power supplies in the process environment required for plant safety, but does not address detailed design of the electrical supply or distribution... guidelines requires the application of sound engineering judgement because the concepts may not be applicable in all cases It is not the intent of CCPS to have the contents of these Guidelines codified 1.3 APPLICABILITY Process safety is a complex subject These Guidelines do not provide all the "answers," but do highlight the safety issues to be addressed in all stages of design They were written for. .. environmental exposure limit 1 INTRODUCTION The Center for Chemical Process Safety (CCPS) has issued a number of Guidelines aimed at the evaluation and mitigation of risks associated with catastrophic events in facilities handling chemicals The purpose of this book is to shift the emphasis on process safety to the earliest stages of the design where process safety issues can be addressed at the lowest cost... representing major chemical, pharmaceutical and hydrocarbon processing companies, worked with engineers of the Stone & Webster Engineering Corporation The intent was to produce a book that presents the process safety design issues needed to address all stages of the evolving design of the facility This book discusses the impact that various engineering design choices will have on the risk of a catastrophic... Center for Chemical Process Safety (CCPS) and those involved in its operation, including its many sponsors whose funding made this project possible; the members of its Technical Steering Committee who conceived of and supported this Guidelines project and the members of its Engineering Practices Subcommittee for their dedicated efforts, technical contributions, and enthusiasm The members of the Engineering. .. Society for Metals American Society of Mechanical Engineers American Society of Safety Engineers American Society of Nondestructive Testing American Society for Testing and Materials American Welding Society Boiling liquid expanding vapor explosion Basic Process Control System British Thermal Units Benzene, toluene and xylene Clean Air Act Clean Air Act Amendments Center for Chemical Process Safety . Guidelines for Engineering Design for Process Safety CENTER FOR CHEMICAL PROCESS SAFETY of the AMERICAN INSTITUTE OF CHEMICAL ENGINEERS 345 . Publication Data Guidelines for engineering design for process safety p. cm. Includes bibliographical references and index. ISBN 0-8169-0565-7 1. Chemical engineering Safety measures . cur- ricula which will improve the safety knowledge and consciousness of engineers. The current book, Guidelines for Engineering Design for Process Safety, is the result of a project