Valvulas de control

CONTROL VALVE HANDBOOK

Fourth Edition

NORTH AMERICA Emerson Process Management Marshalltown, Iowa 50158 USA T 1 (641) 754−3011 F 1 (641) 754−2830 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 ASIA PACIFIC Emerson Process Management Singapore 128461 Singapore T +(65) 67778211 F +(65) 6777 0947 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 MIDDLE EAST & AFRICA Emerson FZE Dubai, United Arab Emirates T +971 4 883 5235 F +971 4 883 5312 www.EmersonProcess.com/Fisher

Fisher is a mark owned by Fisher Controls International LLC, a member ofthe 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 orguarantees, 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

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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, safety, profitability, andecology. 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 turbinebypass systems. D Chapter 8 offers typical control valve installation and maintenance procedures. 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 botha textbook and a reference on the strongest link in the control loop: the control valve and its accessories. This book includes extensive and proven knowledge from leading experts in the process control field including contributions from the ISA and the Crane Company.
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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 . . . . . . . . . . . . . . ....