CONTROL VALVE HANDBOOK Fourth Edition ii NORTH AMERICA Emerson Process Management Marshalltown, Iowa 50158 USA T 1 (641) 754−3011 F 1 (641) 754−2830 www.EmersonProcess.com/Fisher LATIN AMERICA Emerson Process Management Sorocaba, Sao Paulo 18087 Brazil T +(55)(15)238−3788 F +(55)(15)228−3300 www.EmersonProcess.com/Fisher EUROPE Emerson Process Management Cernay 68700 France T +(33) (0)3 89 37 64 00 F +(33) (0)3 89 37 65 18 www.EmersonProcess.com/Fisher MIDDLE EAST & AFRICA Emerson FZE Dubai, United Arab Emirates T +971 4 883 5235 F +971 4 883 5312 www.EmersonProcess.com/Fisher ASIA PACIFIC Emerson Process Management Singapore 128461 Singapore T +(65) 6777 8211 F +(65) 6777 0947 www.EmersonProcess.com/Fisher Fisher is a mark owned by Fisher Controls International LLC, a member of the Emerson Process Management business division of Emerson Electric Co. The Emerson logo is a trademark and service mark of Emerson Electric Co. All other marks are the property of their respective owners. The contents of this publication are presented for informational purposes only, and while every effort has been made to ensure their accuracy, they are not to be construed as warranties or guarantees, express or implied, regarding the products or services described herein or their use or applicability. We reserve the right to modify or improve the designs or specifications of such products at any time without notice. Neither Emerson, Emerson Process Management nor any of their affiliated entities assumes responsibility for the selection, use and maintenance of any product. Responsibility for the selection, use and maintenance of any product remains with the purchaser and end-user. Printed in U.S.A. EFisher Controls International LLC 2005 D101881X012 iii Preface to Fourth Edition Control valves are an increasingly vital component of modern manufacturing around the world. Properly selected and maintained control valves increase efficiency, safe- ty, profitability, and ecology. The Control Valve Handbook has been a primary reference since its first printing in 1965. This fourth edition presents vital information on control valve performance and the latest technologies. D Chapter 1 offers an introduction to control valves including definitions for common control valve and instrumentation terminology. D Chapter 2 develops the vital topic of control valve performance. D Chapter 3 covers valve and actuator types. D Chapter 4 describes digital valve controllers, analog positioners, boosters, and other control valve accessories. D Chapter 5 is a comprehensive guide to selecting the best control valve for an application. D Chapter 6 covers the selection and use of special control valves. D Chapter 7 covers desuperheaters, steam conditioning valves, and turbine bypass systems. D Chapter 8 offers typical control valve installation and maintenance proce- dures. D Chapter 9 includes information on control valve standards and approval agencies throughout the world. D Chapter 10 offers useful tables of engineering reference data. D Chapter 11 includes piping reference data. D Chapter 12 is a handy resource for common conversions. The Control Valve Handbook is both a textbook and a reference on the strongest link in the control loop: the control valve and its accessories. This book includes exten- sive and proven knowledge from leading experts in the process control field includ- ing contributions from the ISA and the Crane Company. iv v Table of Contents Chapter 1. Introduction to Control Valves 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . What Is A Control Valve? 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Process Control Terminology 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sliding-Stem Control Valve Terminology 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Rotary-Shaft Control Valve Terminology 13. . . . . . . . . . . . . . . . . . . . . . . . . . . . Control Valve Functions and Characteristics Terminology 16. . . . . . . . . . . . . Other Process Control Terminology 18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Chapter 2. Control Valve Performance 23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Process Variability 23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Dead Band 25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Actuator-Positioner Design 27. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Valve Response Time 29. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Valve Type And Characterization 31. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Valve Sizing 36. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Economic Results 37. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Summary 39. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Chapter 3. Valve and Actuator Types 41. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Control Valves 41. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Globe Valves 41. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Single-Port Valve Bodies 41. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Balanced-Plug Cage-Style Valve Bodies 43. . . . . . . . . . . . . . . . . . . . . . High Capacity, Cage-Guided Valve Bodies 43. . . . . . . . . . . . . . . . . . . . Port-Guided Single-Port Valve Bodies 44. . . . . . . . . . . . . . . . . . . . . . . . . Double-Ported Valve Bodies 44. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Three-Way Valve Bodies 45. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Table of Contents vi Rotary Valves 45. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Butterfly Valve Bodies 45. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . V-Notch Ball Control Valve Bodies 46. . . . . . . . . . . . . . . . . . . . . . . . . . . . Eccentric-Disk Control Valve Bodies 46. . . . . . . . . . . . . . . . . . . . . . . . . . Eccentric-Plug Control Valve Bodies 47. . . . . . . . . . . . . . . . . . . . . . . . . . Control Valve End Connections 47. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Screwed Pipe Threads 47. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Bolted Gasketed Flanges 48. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Welding End Connections 48. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Valve Body Bonnets 49. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Extension Bonnets 50. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Bellows Seal Bonnets 51. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Control Valve Packing 52. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . PTFE V-Ring 52. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Laminated and Filament Graphite 52. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . USA Regulatory Requirements for Fugitive Emissions 53. . . . . . . . . . . . . Single PTFE V-Ring Packing 54. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ENVIRO-SEAL R PTFE Packing 54. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ENVIRO-SEAL R Duplex Packing 55. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . KALREZ R Packing 55. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ENVIRO−SEAL R Graphite ULF 55. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . HIGH-SEALt Graphite ULF 55. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ENVIRO-SEAL R Graphite for Rotary Valves 57. . . . . . . . . . . . . . . . . . . . . Graphite Ribbon for Rotary Valves 57. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Characterization of Cage-Guided Valve Bodies 58. . . . . . . . . . . . . . . . . . . . . . Characterized Valve Plugs 59. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Valve Plug Guiding 60. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Restricted-Capacity Control Valve Trim 61. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Actuators 61. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Diaphragm Actuators 62. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Piston Actuators 63. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Electrohydraulic Actuators 64. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Manual Actuators 64. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Rack and Pinion Actuators 64. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Electric Actuators 64. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Chapter 4. Control Valve Accessories 67. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Positioners 67. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Other Control Valve Accessories 69. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Limit Switches 69. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Solenoid Valve Manifold 71. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Supply Pressure Regulator 71. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Pneumatic Lock-Up Systems 72. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Fail-Safe Systems for Piston Actuators 72. . . . . . . . . . . . . . . . . . . . . . . . . . Electro-Pneumatic Transducers 72. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Electro-Pneumatic Valve Positioners 72. . . . . . . . . . . . . . . . . . . . . . . . . . . . Table of Contents vii Diagnostics 74. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Chapter 5. Control Valve Selection 75. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Valve Body Materials 76. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Designations for the High Nickel Alloys 77. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Pressure-Temperature Ratings for Standard Class 78. . . . . . . . . . . . . . . . . . . Cast Carbon Steel (ASTM A216 Grade WCC) 78. . . . . . . . . . . . . . . . . . . . Cast Chromium-Molybdenum Steel (ASTM A217 Grade WC9) 79. . . . . . Cast Chromium-Molybdenum Steel (ASTM A217 Grade C5) 80. . . . . . . . Cast Type 304 Stainless Steel (ASTM A351 Grade CF3) 81. . . . . . . . . . . Cast Type 316 Stainless Steel (ASTM A351 Grades CF8M and CG8M) 82 Pressure-Temperature Ratings for ASTM A216 Cast Iron Valves 84. . . . . . . Pressure-Temperature Ratings for ASTM B61 and B62 Cast Bronze Valves 85. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Face-to-Face Dimensions for Flanged Globe-Style Control Valves 86. . . . . Face-to-Face Dimensions for Buttweld-End Globe-Style Control Valves 88. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Face-to-Face Dimensions for Socket Weld-End Globe-Style Control Valves 89. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Face-to-Face Dimensions for Screwed-End Globe-Style Control Valves 90. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Face-to-Centerline Dimensions for Raised Face Globe-Style Angle Control Valves 90. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Face-to-Face Dimensions for Separable Flanged Globe-Style Control Valves 90. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Face-to-Face Dimensions for Flangeless, Partial-Ball Control Valves 91. . . Face-to-Face Dimensions for Single Flange (Lug-Type) and Flangeless (Wafer-Type) Butterfly Control Valves 91. . . . . . . . . . . . . . . . . . . . Face-to-Face Dimensions for High Pressure Butterfly Valves with Offset Design 92. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Wear & Galling Resistance Chart Of Material Combinations 92. . . . . . . . . . . Control Valve Seat Leakage Classifications 93. . . . . . . . . . . . . . . . . . . . . . . . . Class VI Maximum Seat Leakage Allowable 94. . . . . . . . . . . . . . . . . . . . . . . . Typical Valve Trim Material Temperature Limits 94. . . . . . . . . . . . . . . . . . . . . . Service Temperature Limitations for Elastomers 95. . . . . . . . . . . . . . . . . . . . . Ambient Temperature Corrosion Information 96. . . . . . . . . . . . . . . . . . . . . . . Elastomer Information 101. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Fluid Compatibility 104. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Control Valve Flow Characteristics 108. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Flow Characteristics 108. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Selection of Flow Characteristic 109. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Valve Sizing 110. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sizing Valves for Liquids 110. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Abbreviations and Terminology 112. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Equation Constants 113. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Determining Fp, the Piping Geometry Factor 114. . . . . . . . . . . . . . . . . . . . . Table of Contents viii Determining qmax (the Maximum Flow Rate) or DPmax (the Allowable Sizing Pressure Drop) 115. . . . . . . . . . . . . . . . . . . . . . . . . . . Determining qmax (the Maximum Flow Rate) 115. . . . . . . . . . . . . . . . . . . . . Determining DPmax (the Allowable Sizing Pressure Drop) 115. . . . . . . . . . Liquid Sizing Sample Problem 117. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sizing Valves for Compressible Fluids 119. . . . . . . . . . . . . . . . . . . . . . . . . . . Determining x TP , the Pressure Drop Ratio Factor 121. . . . . . . . . . . . . . . . . Compressible Fluid Sizing Sample Problem No. 1 121. . . . . . . . . . . . . . . . Compressible Fluid Sizing Sample Problem No. 2 123. . . . . . . . . . . . . . . . Representative Sizing Coefficients for Single-Ported Globe-Style Valve Bodies 126. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Representative Sizing Coefficients for Rotary-Shaft Valves 127. . . . . . . Actuator Sizing 129. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Globe Valves 129. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A. Unbalance Force 129. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Typical Unbalance Areas of Control Valves 129. . . . . . . . . . . . . . . . B. Force to Provide Seat Load 130. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C. Packing Friction 131. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Typical Packing Friction Values 132. . . . . . . . . . . . . . . . . . . . . . . . . . D. Additional Forces 132. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Actuator Force Calculations 133. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Rotary Actuator Sizing 133. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Torque Equations 133. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Breakout Torque 133. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Dynamic Torque 133. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Typical Rotary Shaft Valve Torque Factors 134. . . . . . . . . . . . . . . . . . . . . . . . . V-Notch Ball Valve with Composition Seal 134. . . . . . . . . . . . . . . . . . . . . . . . . High Performance Butterfly Valve with Composition Seal 134. . . . . . . . . . . . . Maximum Rotation 134. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Non-Destructive Test Procedures 134. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Magnetic Particle (Surface) Examination 135. . . . . . . . . . . . . . . . . . . . . . . . Liquid Penetrant (Surface) Examination 135. . . . . . . . . . . . . . . . . . . . . . . . . Radiographic (Volumetric) Examination 135. . . . . . . . . . . . . . . . . . . . . . . . . Ultrasonic (Volumetric) Examination 136. . . . . . . . . . . . . . . . . . . . . . . . . . . . Cavitation and Flashing 136. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Choked Flow Causes Flashing and Cavitation 136. . . . . . . . . . . . . . . . . . . Valve Selection for Flashing Service 137. . . . . . . . . . . . . . . . . . . . . . . . . . . Valve Selection for Cavitation Service 138. . . . . . . . . . . . . . . . . . . . . . . . . . Noise Prediction 139. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Aerodynamic 139. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hydrodynamic 140. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Noise Control 140. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Noise Summary 143. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Packing Selection 144. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Packing Selection Guidelines for Sliding−Stem Valves 145. . . . . . . . . . . . . . . Packing Selection Guidelines for Rotary Valves 146. . . . . . . . . . . . . . . . . . . . Chapter 6. Special Control Valves 147. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Table of Contents ix High Capacity Control Valves 147. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Low Flow Control Valves 148. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . High-Temperature Control Valves 148. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cryogenic Service Valves 149. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Customized Characteristics and Noise Abatement Trims 150. . . . . . . . . . . . . Control Valves for Nuclear Service in the USA 151. . . . . . . . . . . . . . . . . . . . . . Valves Subject to Sulfide Stress Cracking 151. . . . . . . . . . . . . . . . . . . . . . . . . Pre-2003 Revisions of MR0175 152. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . NACE MR0175/ISO 15156 152. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . NACE MR0103 153. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Chapter 7. Steam Conditioning Valves 155. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Understanding Desuperheating 155. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Technical Aspects of Desuperheating 156. . . . . . . . . . . . . . . . . . . . . . . . . . Typical Desuperheater Designs 158. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Fixed Geometry Nozzle Design 158. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Variable Geometry Nozzle Design 159. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Self-Contained Design 159. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Steam Atomized Design 160. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Geometry-Assisted Wafer Design 161. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Understanding Steam Conditioning Valves 161. . . . . . . . . . . . . . . . . . . . . . . . Steam Conditioning Valves 162. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Steam Cooler 164. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Steam Sparger 164. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Understanding Turbine Bypass Systems 165. . . . . . . . . . . . . . . . . . . . . . . . . . Turbine Bypass System Components 166. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Turbine Bypass Valves 166. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Turbine Bypass Water Control Valves 166. . . . . . . . . . . . . . . . . . . . . . . . . . Electro-Hydraulic System 166. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Chapter 8. Installation and Maintenance 167. . . . . . . . . . . . . . . . . . . . . . . . . . . Proper Storage and Protection 167. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Proper Installation Techniques 168. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Read the Instruction Manual 168. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Be Sure the Pipeline Is Clean 168. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Inspect the Control Valve 168. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Use Good Piping Practices 168. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Control Valve Maintenance 169. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Reactive Maintenance 169. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Preventive Maintenance 169. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Predictive Maintenance 170. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Using Control Valve Diagnostics 170. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Instrument Air Leakage 170. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Supply Pressure 170. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Travel Deviation and Relay Adjustment 171. . . . . . . . . . . . . . . . . . . . . . . . Table of Contents x Instrument Air Quality 171. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . In-Service Friction and Friction Trending 171. . . . . . . . . . . . . . . . . . . . . . . Other Examples 172. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Continued Diagnostics Development 172. . . . . . . . . . . . . . . . . . . . . . . . . . Actuator Diaphragm 172. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Stem Packing 172. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Seat Rings 173. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Grinding Metal Seats 173. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Replacing Seat Rings 173. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Bench Set 174. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Chapter 9. Standards and Approvals 175. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Control Valve Standards 175. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . American Petroleum Institute (API) 175. . . . . . . . . . . . . . . . . . . . . . . . . . . . . American Society of Mechanical Engineers (ASME) 175. . . . . . . . . . . . . . European Committee for Standardization (CEN) 176. . . . . . . . . . . . . . . . . European Industrial Valve Standards 176. . . . . . . . . . . . . . . . . . . . . . . . European Material Standards 176. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . European Flange Standards 176. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Fluid Controls Institute (FCI) 176. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Instrument Society of America (ISA) 177. . . . . . . . . . . . . . . . . . . . . . . . . . . . International Electrotechnical Commission (IEC) 177. . . . . . . . . . . . . . . . . International Standards Organization (ISO) 178. . . . . . . . . . . . . . . . . . . . . . Manufacturers Standardization Society (MSS) 178. . . . . . . . . . . . . . . . . . . NACE International 178. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Product Approvals for Hazardous (Classified) Locations 178. . . . . . . . . . . . . References 178. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Canadian Standards Association (CSA) Standards 178. . . . . . . . . . . . European Committee for Electrotechnical Standardization (CENELEC) Standards 178. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Instrument Society of America (ISA) Standards 178. . . . . . . . . . . . . . . . International Electrotechnical Commission (IEC) Standards 178. . . . . National Electrical Manufacturer’s Association (NEMA) Standards 179. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . National Fire Protection Association (NFPA) Standards 179. . . . . . . . . North American Approvals 179. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Approval Agencies 179. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Types of Protection 179. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Nomenclature 179. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hazardous Location Classification 179. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Temperature Code 180. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . NEMA Enclosure Rating 181. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . General Locations 181. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hazardous (Classified) Locations 182. . . . . . . . . . . . . . . . . . . . . . . . . . . CSA Enclosure Ratings 182. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Intrinsically Safe Apparatus 182. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [...]... appropriate output signal to the final control element Control Loop: (See Closed Loop.) Control Range: The range of valve travel over which a control valve can maintain the installed valve gain between the normalized values of 0.5 and 2.0 Control Valve: (See Control Valve Assembly.) Control Valve Assembly: Includes all components normally mounted on the valve: the valve body assembly, actuator, positioner,... operate the valve, and a variety 1 Chapter 1 Introduction to Control Valves of additional valve accessories, which can include positioners, transducers, supply pressure regulators, manual operators, snubbers, or limit switches Other chapters of this handbook supply more detail about each of these control valve assembly components Whether it is called a valve, control valve or a control valve assembly... The flow-controlling member of rotary-shaft control valves using a complete sphere with a flow passage through it The flow passage equals or matches the pipe diameter 13 Chapter 1 Introduction to Control Valves W4920/IL SEGMENTED BALL VALVE W4641 CONVENTIONAL DISK BUTTERFLY VALVE W6213/IL W5477/IL ECCENTRIC DISK VALVE CONTOURED DISK BUTTERFLY VALVE Figure 1-14 Typical Rotary-Shaft Control Valve Constructions... split valve body Valve Body: The main pressure boundary of the valve that also provides the pipe connecting ends, the fluid flow passageway, and supports the seating surfaces and the valve closure member Among the most common valve body constructions are: a) single-ported valve bodies having one port and one valve plug; b) double-ported valve bodies having two ports and one valve plug; c) two-way valve. .. control valve The control valve manipulates a flowing fluid, such as gas, steam, water, or chemical compounds, to compensate for the load disturbance and keep the regulated process variable as close as possible to the desired set point Many people who talk about control valves or valves are really referring to a control valve assembly The control valve assembly typically consists of the valve body, the... change in the output signal Dead band is the name given to a general phenomenon that can apply to any device For the valve Chapter 1 Introduction to Control Valves vice, the most common final control element in the process control industries is the control valve assembly The control valve manipulates a flowing fluid, such as gasses, steam, water, or chemical compounds, to compensate for the load disturbance... to seal against leakage around the closure Chapter 1 Introduction to Control Valves W0467/IL Figure 1-9 Reverse Double-Ported Globe-Style Valve Body W0665/IL Figure 1-11 Three-Way Valve with Balanced Valve Plug W0992/IL W0971/IL Figure 1-10 Flanged Angle-Style Control Valve Body Figure 1-12 Valve Body with Cage-Style Trim, Balanced Valve Plug, and Soft Seat packing parts are shown in figure 1-13 member... is not the weakest link Following are definitions for process control, sliding-stem control valve, rotary-shaft control valve, and other control valve functions and characteristics terminology NOTE: Definitions with an asterisk (*) are from the ISA Control Valve Terminology standard S75.05, used with permission Process Control Terminology Accessory: A device that is mounted on the actuator to complement... the control valve is a critical part of the control loop It is not accurate to say that the control valve is the most important part of the loop It is useful to think of a control loop as an instrumentation chain Like any other chain, the whole chain is only as good as its weakest link It is important to ensure that the control valve is not the weakest link Following are definitions for process control, ... Constructions 14 Chapter 1 Introduction to Control Valves Ball, Segmented: The flow-controlling member of rotary shaft control valves using a partial sphere with a flow passage through it Flangeless valves are held between ANSI-class flanges by long through-bolts (sometimes also called wafer-style valve bodies) Ball, V-notch: The most common type of segmented ball control valve The V-notch ball includes a polished . ensure that the control valve is not the weak- est link. Following are definitions for process control, sliding-stem control valve, rotary-shaft control valve, and other control valve functions. Loop.) Control Range: The range of valve travel over which a control valve can maintain the installed valve gain be- tween the normalized values of 0.5 and 2.0. Control Valve: (See Control Valve Assembly.) Control. switches. Other chapters of this handbook sup- ply more detail about each of these control valve assembly components. Whether it is called a valve, control valve or a control valve assembly is not as