Preface xxiv Acknowledgments xxvii 23 Pressure Relieving Devices and Emergency Relief System Design 1 23.0 Introduction 1 23.1 Types of Positive Pressure Relieving Devices (See Manufacturers'' Catalogs for Design Details) 2 23.2 Types of Valves/Relief Devices 6 Conventional Safety Relief Valve 6 Balanced Safety Relief Valve 7 Special Valves 7 Rupture Disk 7 Example 23.1 15 23.3 Materials of Construction 18 Safety and Relief Valves: Pressure-Vacuum Relief Values 18 Rupture Disks 19 23.4 General Code Requirements [1] 20 23.5 Relief Mechanisms 20 Reclosing Devices, Spring Loaded 20 Non-Reclosing Pressure Relieving Devices 21 23.
6 Pressure Settings and Design Basis 21 23.7 Unfired Pressure Vessels Only, But Not Fired or Unfired Steam Boilers 24 Non-Fire Exposure 24 External Fire or Heat Exposure Only and Process Relief 24 23.8 Relieving Capacity of Combinations of Safety Relief Valves and Rupture Disks or Non-Reclosure Devices (Reference ASME Code, Par. UG-127, U-132) 24 Primary Relief 24 Rupture Disk Devices, [44] Par UG-127 25 Footnotes to ASME Code 26 23.9 Establishing Relieving or Set Pressures 27 Safety and Safety Relief Valves for Steam Service 28 23.10 Selection and Application 28 Causes of System Overpressure 28 23.11 Capacity Requirements Evaluation for Process Operation (Non-Fire) 29 Installation 34 23.12 Piping Design 37 Pressure Drops 37 Line Sizing 37 23.
13 Selection Features: Safety, Safety-Relief Valves, and Rupture Disks 44 23.14 Calculations of Relieving Areas: Safety and Relief Valves 46 23.15 Standard Pressure Relief Valves Relief Area Discharge Openings 46 23.16 Sizing Safety Relief Type Devices for Required Flow Area at Time of Relief 47 23.17 Effects of Two-Phase Vapor-Liquid Mixture on Relief Valve Capacity 47 23.18 Sizing for Gases or Vapors or Liquids for Conventional Valves with Constant Backpressure Only 47 Procedure 48 Establish Critical Flow for Gases and Vapors 48 Example 23.2: Flow through Sharp Edged Vent Orifice (Adapted after [41]) 54 23.19 Orifice Area Calculations [42] 54 23.
20 Sizing Valves for Liquid Relief: Pressure-Relief Valves Requiring Capacity Certification [5D] 60 23.21 Sizing Valves For Liquid Relief: Pressure Relief Valves Not Requiring Capacity Certification [5D] 61 23.22 Reaction Forces 66 Example 23.3 67 Solution 67 Example 23.4 69 Solution 70 23.23 Calculations of Orifice Flow Area using Pressure Relieving Balanced Bellows Valves, with Variable or Constant Backpressure 72 23.24 Sizing Valves for Liquid Expansion (Hydraulic Expansion of Liquid Filled Systems/ Equipment/Piping) 80 23.25 Sizing Valves for Subcritical Flow: Gas or Vapor But Not Steam [5d] 81 23.
26 Emergency Pressure Relief: Fires and Explosions Rupture Disks 84 23.27 External Fires 84 23.28 Set Pressures for External Fires 85 23.29 Heat Absorbed 85 The Severe Case 85 23.30 Surface Area Exposed to Fire 86 23.31 Relief Capacity for Fire Exposure 87 23.32 Code Requirements for External Fire Conditions 87 23.33 Design Procedure 88 Example 23.
5 88 Solution 88 23.34 Pressure Relief Valve Orifice Areas on Vessels Containing Only Gas, Unwetted Surface 92 23.35 Rupture Disk Sizing Design and Specification 93 23.36 Specifications to Manufacturer 93 23.37 Size Selection 94 23.38 Calculation of Relieving Areas: Rupture Disks for Non-Explosive Service 94 23.39 The Manufacturing Range (MR) 95 23.40 Selection of Burst Pressure for Disk, P b (Table 23.
3) 95 Example 23.6: Rupture Disk Selection 98 23.41 Effects of Temperature on Disk 98 23.42 Rupture Disk Assembly Pressure Drop 101 23.43 Gases and Vapors: Rupture Disks [5a, Par, 4.8] 101 Volumetric Flow: scfm Standard Conditions (1.4.7 psia and 60°F) 102 Steam: Rupture Disk Sonic Flow; Critical Pressure = 0.
55 and P 2 /p 1 is Less Than Critical Pressure Ratio of 0.55 103 23.44 API for Subsonic Flow: Gas or Vapor (Not Steam) 103 23.45 Liquids: Rupture Disk 104 23.46 Sizing for Combination of Rupture Disk and Pressure Relief Valve in Series Combination 105 Example 23.7: Safety Relief Valve for Process Overpressure 106 Example 23.8: Rupture Disk External Fire Condition 106 Solution 107 Heat Input 107 Total Heat Input (from Figure 23.30a) 107 Quantity of Vapor Released 107 Critical Flow Pressure 107 Disk Area 108 Example 23.
9: Rupture Disk for Vapors or Gases; Non-Fire Condition 108 Solution 108 Example 23.10: Liquids Rupture Disk 109 Example 23.11: Liquid Overpressure, Figure 23.34 110 23.47 Pressure-Vacuum Relief for Low-Pressure Storage Tanks 110 23.48 Basic Venting For Low-Pressure Storage Vessels 111 23.49 Non-Refrigerated Above Ground Tanks; API-Std. 2000 112 23.
50 Boiling Liquid Expanding Vapor Explosions (BLEVEs) 113 Ignition of Flammable Mixtures 116 23.51 Managing Runaway Reactions 116 Hydroprocessing Units 117 Acid/Base Reactions 118 Methanation 118 Alkylation Unit Acid Runaway 118 23.51.1 Runaway Reactions: DIERS 118 23.52 Hazard Evaluation in the Chemical Process Industries 120 23.53 Hazard Assessment Procedures 121 Exotherms 122 Accumulation 122 23.54 Thermal Runaway Chemical Reaction Hazards 122 Heat Consumed Heating the Vessel. The -Factor 123 Onset Temperature 124 Time-To-Maximum Rate 125 Maximum Reaction Temperature 125 Vent Sizing Package (VSP) 126 Vent Sizing Package 2 TM (VSP2 TM) 127 Advanced Reactive System Screening Tool (ARSST) 128 23.
55 Two-Phase Flow Relief Sizing for Runaway Reaction 128 Runaway Reactions 131 Vapor Pressure Systems 132 Gassy Systems 132 Hybrid Systems 132 Simplified Nomograph Method 134 Vent Sizing Methods 138 Vapor Pressure Systems 138 Fauske''s Method 140 Gassy Systems 142 Homogeneous Two-Phase Venting Until Disengagement 143 Two-Phase Flow Through an Orifice 144 Conditions of Use 145 23.56 Discharge System 145 Design of The Vent Pipe 145 Safe Discharge 146 Direct Discharge to The Atmosphere 147 Example 23.12 147 Tempered Reaction 147 Solution 147 Example 23.13 149 Solution 149 Example 23.14 150 Solution 151 Example 23.15 152 Solution 152 DIERS Final Reports 155 23.57 Sizing for Two-Phase Fluids 155 Example 23.16 161 Solution 162 Example 23.
17 164 Solution 164 Example 23.18 172 Example 23.19 177 Solution 178 Type 3 Integral Method [5] 179 Example 23.20 [76] 180 Solution 181 23.58 Flares/Flare Stacks 182 Flares 184 Sizing 184 Flame Length [5c] 186 Flame Distortion [5c] Caused by Wind Velocity 187 Flare Stack Height 189 Flaring Toxic Gases 194 Purging of Flare Stacks and Vessels/Piping 195 Pressure Purging 195 Example 23.21: Purge Vessel by Pressurization Following the Method of [41] 195 23.59 Compressible Flow for Discharge Piping 197 Design Equations for Compressible Fluid Flow for Discharge Piping 197 Critical Pressure, P crit 200 Compressibility Factor Z 201 Friction factor, f 202 Discharge Line Sizing 203 23.60 Vent Piping 204 Discharge Reactive Force 204 Example 23.
22 205 Solution 206 Example 23.23: Flare and Relief Blowdon System 208 Solution 208 A Rapid Solution for Sizing Depressuring Lines [5c] 208 Codes and Standards 212 Discharge Locations 213 Process Safety Incidents with Relief Valve Failures and Flarestacks 214 A Case Study on Williams Geismar Olefins Plant, Geismar, Louisiana [95] 214 Process Flow of the Olefins 214 The Incident 216 Technical Analysis 219 Key Lessons 222 Explosions in Flarestacks 225 Relief Valves 227 Location 228 Relief Valve Registers 228 Relief Valve Faults [92] 229 Tailpipes [92] 230 GLOSSARY 230 Acronyms and Abbreviations 239 Nomenclature 240 Subscripts 244 Greek Symbols 244 References 245 World Wide Web on Two-Phase Relief Systems 247 24 Process Safety and Energy Management in Petroleum Refinery 249 24.1 Introduction 249 24.2 Process Safety 250 24.2.1 Process Safety Information 253 24.2.2 Conduct of Operations (COO) and Operational Discipline (OD) 254 Process Safety Culture: BP Refinery Explosion, Texas City, 2005 257 Detailed Description 257 Causes 258 Key Lessons 260 Process Safety Culture 260 Selected CSB Findings 260 Selected Baker Panel Finding 261 Process Knowledge Management 261 Training and Performance Assurance 261 Management of Change (MOC) 261 Asset Integrity and Reliability 261 24.
2.3 Process Hazard Analysis 262 Safe Operating Limits 263 Impact on Other Process Safety Elements 264 24.3 General Process Safety Hazards in a Refinery 265 Desalters 266 Critical Operating Parameters Impacting Process Safety 266 The Quality of Aqueous Effluent from Desalters 267 Desalter Water Supply 267 Vibration within Relief Valve (RV) Pipewor.