Control Valve Handbook - Industrial Automation …

1 Control Valve . Handbook . Third Edition FISHER CONTROLS INTERNATIONAL, INC. Marshalltown, Iowa 50158 Cernay 68700 France Sao Paulo 05424 Brazil Singapore 128461. Copyright 1965, 1998, 1999, Reprinted in 1999 and 2001. Fisher Controls International, Inc. All Rights Reserved. Fisher, ENVIRO-SEAL and FIELDVUE are marks owned by Fisher Controls International, Inc., a business of Emerson Process Management. The Emerson logo is a trademark and service mark of Emerson Electric Co. All other marks are the property of their respective owners. Printed in ii Preface to Third Edition Control valves are an increasingly vital component of modern manufacturing around the world. Well selected and maintained Control valves increase efficiency, safety, profitability, and ecology. The Control Valve Handbook has been a primary reference for more than 30 years. This third edition is a complete revision and update that includes vital information on Control Valve performance and the latest technologies.

2 Chapter 1 offers an introduction to Control valves including definitions for common Control Valve and instrumentation terminology. Chapter 2 develops the vital topic of Control Valve performance. Chapter 3 covers Valve and actuator types. Chapter 4 describes digital Valve controllers, analog positioners, boosters, and other Control Valve accessories. Chapter 5 is a comprehensive guide to selecting the best Control Valve for an application. Chapter 6 covers the selection and use of special Control valves . Chapter 7 covers desuperheaters, steam conditioning valves , and turbine bypass systems. Chapter 8 offers typical Control Valve installation and maintenance proce- dures. Chapter 9 includes information on Control Valve standards and approval agencies throughout the world. Chapter 10 offers useful tables of engineering reference data. Chapter 11 includes piping reference data. Chapter 12 is a handy resource for common conversions.

3 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. iii iv 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.

4 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 .. 44. Port-Guided Single-Port Valve Bodies .. 44. Double-Ported Valve Bodies .. 44. Three-Way Valve Bodies .. 45. v Table of Contents Rotary valves .. 45. Butterfly Valve Bodies .. 45. V-Notch Ball Control Valve Bodies .. 46. Eccentric-Disk Control Valve Bodies .. 47. Eccentric-Plug Control Valve Bodies .. 47. Control Valve End Connections .. 48. Screwed Pipe Threads .. 48. Bolted Gasketed Flanges .. 48. Welding End Connections .. 49. 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. Characterization of Cage-Guided Valve Bodies .. 56. Characterized Valve Plugs .. 58. Valve Plug Guiding.

5 59. Restricted-Capacity Control Valve Trim .. 60. Actuators .. 60. Diaphragm Actuators .. 61. Piston Actuators .. 61. Electrohydraulic Actuators .. 63. Manual Actuators .. 63. Rack and Pinion Actuators .. 64. Electric Actuators .. 64. Chapter 4. Control Valve Accessories .. 65. Positioners .. 65. Other Control Valve Accessories .. 67. Limit Switches .. 69. Solenoid Valve Manifold .. 69. Supply Pressure Regulator .. 70. Pneumatic Lock-Up Systems .. 70. Fail-Safe Systems for Piston Actuators .. 70. Electro-Pneumatic Transducers .. 70. Electro-Pneumatic Valve Positioners .. 72. PC Diagnostic Software .. 72. Chapter 5. Control Valve Selection .. 73. Valve Body Materials .. 74. Designations for the High Nickel Alloys .. 75. Pressure-Temperature Ratings for Standard Class .. 76. ASTM A216 Grade WCC valves .. 76. vi Table of Contents ASTM A217 Grade WC9 valves .. 77. ASTM A217 Grade C5 valves .. 78. ASTM A351 Grade CF3 valves .

6 79. ASTM A351 Grade CF8M and ASTM A479 Grade UNS S31700 valves .. 80. Pressure-Temperature Ratings for ASTM A216 Cast Iron valves .. 82. Pressure-Temperature Ratings for ASTM B61 and B62 Cast Bronze valves .. 83. Class Designation and PN Numbers .. 83. Face to Face Dimensions for Flanged Globe Style Control valves .. 85. Face to Face Dimensions for Buttweld End Globe Style Control valves .. 87. Face to Face Dimensions for Socket Weld End Globe Style Control valves .. 88. Face-to-Face Dimensions for Screwed-End Globe-Style Control valves .. 89. Face-to-Centerline Dimensions for Raised Face Globe-Style Angle Control valves .. 89. Face-to-Face Dimensions for Separable Flanged Globe-Style Control valves .. 89. Face-to-Face Dimensions for Flangeless, Partial-Ball Control valves .. 90. Face-to-Face Dimensions for Single Flange (Lug-Type) and Flangeless (Wafer-Type) Butterfly Control valves .. 90. Face-to-Face Dimensions for High Pressure Butterfly valves with Offset Design.

7 91. Wear & Galling Resistance Chart Of Material Combinations .. 91. Control Valve Seat Leakage Classifications .. 92. Class VI Maximum Seat Leakage Allowable .. 93. Typical Valve Trim Material Temperature Limits .. 93. Service Temperature Limitations for Elastomers .. 94. Ambient Temperature Corrosion Information .. 95. Elastomer Information .. 100. Fluid Compatibility .. 103. Control Valve Flow Characteristics .. 107. Flow Characteristics .. 107. Selection of Flow Characteristic .. 108. Valve Sizing .. 109. Sizing valves for Liquids .. 109. Abbreviations and Terminology .. 111. Equation Constants .. 112. Determining Fp, the Piping Geometry Factor .. 113. Determining qmax (the Maximum Flow Rate) or DPmax (the Allowable Sizing Pressure Drop) .. 114. Determining qmax (the Maximum Flow Rate) .. 114. Determining DPmax (the Allowable Sizing Pressure Drop) .. 114. Liquid Sizing Sample Problem .. 116. Sizing valves for Compressible Fluids.

8 118. vii Table of Contents Determining xTP, the Pressure Drop Ratio Factor .. 120. Compressible Fluid Sizing Sample Problem No. 1 .. 120. Compressible Fluid Sizing Sample Problem No. 2 .. 122. Representative Sizing Coefficients for Single Ported Globe Style Valve Bodies .. 125. Representative Sizing Coefficients for Rotary Shaft valves .. 126. Actuator Sizing .. 128. Globe valves .. 128. A. Unbalance Force .. 128. Typical Unbalance Areas of Control valves .. 128. B. Force to Provide Seat Load .. 129. C. Packing Friction .. 130. Typical Packing Friction Values .. 131. D. Additional Forces .. 131. Actuator Force Calculations .. 132. Rotary Actuator Sizing .. 132. Torque Equations .. 132. Breakout Torque .. 132. Dynamic Torque .. 132. Typical Rotary Shaft Valve Torque Factors .. 133. V Notch Ball Valve with Composition Seal .. 133. High Performance Butterfly Valve with Composition Seal .. 133. Maximum Rotation.

9 133. Non-Destructive Test Procedures .. 133. Magnetic Particle (Surface) Examination .. 134. Liquid Penetrant (Surface) Examination .. 134. Radiographic (Volumetric) Examination .. 134. Ultrasonic (Volumetric) Examination .. 135. Cavitation and Flashing .. 135. Choked Flow Causes Flashing and Cavitation .. 135. Valve Selection for Flashing Service .. 136. Valve Selection for Cavitation Service .. 137. Noise Prediction .. 138. Aerodynamic .. 138. Hydrodynamic .. 139. Noise Control .. 139. Noise Summary .. 142. Packing Selection .. 143. Packing Selection Guidelines for Sliding Stem valves .. 144. Packing Selection Guidelines for Rotary valves .. 145. Chapter 6. Special Control valves .. 147. High Capacity Control valves .. 147. Low Flow Control valves .. 148. High-Temperature Control valves .. 148. Cryogenic Service valves .. 149. viii Table of Contents Customized Characteristics and Noise Abatement Trims.

10 150. Control valves for Nuclear Service in the USA .. 150. valves Subject to Sulfide Stress Cracking .. 151. Chapter 7. Steam Conditioning valves .. 153. Understanding Desuperheating .. 153. Technical Aspects of Desuperheating .. 154. Typical Desuperheater Designs .. 156. Fixed Geometry Nozzle Design .. 156. Variable Geometry Nozzle Design .. 157. Self-Contained Design .. 157. Steam Atomized Design .. 158. Geometry-Assisted Wafer Design .. 159. Understanding Steam Conditioning valves .. 159. Steam Conditioning Valve Designs .. 160. Feedforward Design .. 160. Manifold Design .. 161. Pressure-Reduction-Only Design .. 163. Understanding Turbine Bypass Systems .. 164. Turbine Bypass System Components .. 164. Turbine Bypass valves .. 165. Turbine Bypass Water Control valves .. 165. Electro-Hydraulic System .. 165. Chapter 8. Installation and Maintenance .. 167. Proper Storage and Protection .. 167. Proper Installation Techniques.