ISA 75 05 01-2016 Control Valve Terminology.pdf

1、 NOTICE OF COPYRIGHT This is a copyright document and may not be copied or distributed in any form or manner without the permission of ISA. This copy of the document was made for the sole use of the person to whom ISA provided it and is subject to the restrictions stated in ISAs license to that pers

2、on. It may not be provided to any other person in print, electronic, or any other form. Violations of ISAs copyright will be prosecuted to the fullest extent of the law and may result in substantial civil and criminal penalties. AMERICAN NATIONAL STANDARD ANSI/ISA-75.05.01-2016 Control Valve Termino

3、logy Approved 9 December 2016 ANSI/ISA-75.05.01-2016 Control Valve Terminology ISBN: 978-1-945541-35-3 Copyright 2016 by the International Society of Automation. All rights reserved. Not for resale. Printed in the United States of America. No part of this publication may be reproduced, stored in a r

4、etrieval system, or transmitted in any form or by any means (electronic mechanical, photocopying, recording, or otherwise), without the prior written permission of the Publisher. ISA 67 Alexander Drive P.O. Box 12277 Research Triangle Park, North Carolina 27709 -3- ANSI/ISA-75.05.01-2016 Preface Thi

5、s preface, as well as all footnotes and annexes, is included for information purposes and is not part of ANSI/ISA-75.05.01-2016. NOTE ANSI/ISA-75.05.01-2016 contains the same material as ANSI/ISA-75.05.01-2000 (R2005). The standard is currently undergoing revision and this publication is to maintain

6、 the document as an ANSI-approved standard for the duration of the revision cycle. This document has been prepared as part of the service of the International Society of Automation (ISA) toward a goal of uniformity in the field of instrumentation. To be of real value, this document should not be sta

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12、ration (www.automationfederation.org), an association of non-profit organizations serving as “The Voice of Automation.“ Through a wholly owned subsidiary, ISA bridges the gap between standards and their implementation with the ISA Security Compliance Institute (www.isasecure.org) and the ISA Wireles

13、s Compliance Institute (www.isa100wci.org). The following people served as members of ISA75.05 and approved ANSI/ISA-75.05.01-2016: NAME COMPANY V. Mezzano, Chairman Fluor Corporation W. Weidman, Managing Director Consultant S. A Rashid Petronas T. Abromaitis S the second stage is the collapse or im

14、plosion of these cavities back into an all-liquid state as the fluid decelerates and static pressure is recovered. 3.30 characterized cam: a component in a valve positioner used to relate the closure member position to the control signal. 3.31 characterized trim: control valve trim that provides def

15、ined flow characteristics, such as equal percentage, linear or quick opening, usually stated in terms of CV or KV versus travel. 3.32 choked flow: a condition wherein the flow rate through a restriction does not increase when the downstream pressure is decreased at a fixed inlet pressure. ANSI/ISA-7

16、5.05.01-2016 -16- 3.33 class: a convenient round number used to designate allowable pressure/temperature ratings for valves and pipe fittings using arbitrary class numbers from tables developed by ASME and ISO for a variety of materials. 3.34 clearance flow: that flow below the minimum controllable

17、flow with the closure member not seated. 3.35 closure member: the movable part of the valve that is positioned in the flow path to modulate the rate of flow through the valve. 3.36 closure member configurations: 3.36.1 characterized: closure member with contoured surface, such as the “vee plug,“ to

18、provide desired flow characteristics. 3.36.2 cylindrical: a cylindrical closure member with a flow passage through it (or a partial cylinder). 3.36.3 eccentric rotary plug: closure member face of a rotary motion valve that is not concentric with the shaft centerline and moves into seat when closing.

19、 3.36.4 eccentric spherical disk: the disk is a spherical segment in a rotary motion valve that is not concentric with the disk shaft and moves into the seat when closing. 3.36.5 linear: a closure member that moves in a line perpendicular to the seating plane. 3.36.6 rotary: a closure member that is

20、 rotated into or away from a seat to modulate flow. 3.36.7 tapered: closure member is tapered and may be lifted from seating surface before rotating to close or open. 3.37 cold working pressure: the maximum pressure rating of a valve or fitting coincident with ambient temperature, generally in the r

21、ange from -29 C to +38 C (-20 F to +100 F). 3.38 compressor: the device, in a weir-type or sleeve (pinch) valve, that the valve stem forces against the backside of the diaphragm or sleeve to cause the diaphragm or sleeve to move and seal against the internal flow passageway of the valve body. 3.39 c

22、ontrol signal override device: a device that overrides the control signal to the valve actuator, e.g., solenoid valves, lock-up valves, bypass valves, etc. 3.40 control valve: a power actuated device that modifies the fluid flow rate in a process control system. It consists of a valve connected to a

23、n actuator mechanism (including all related accessories) that is capable of changing the position of a closure member in the valve in response to a signal from the controlling system. 17 ANSI/ISA-75.05.01-2016 3.41 control valve gain: the change in the flow rate as a function of the change in valve

24、travel. It is the slope of the installed flow characteristic curve. 3.42 cracked flow: a nonstandard term. See “clearance flow.“ 3.43 cycling life: a number of cycles over which a device will operate without changing its performance beyond tolerance. 3.44 CWP: see “cold working pressure.” 3.45 dashp

25、ot: a less preferred term. See “snubber.“ 3.46 data plate: a less preferred term. See “nameplate.“ 3.47 dead band, control valve: the range through which a control valves input signal may be varied, upon reversal of direction, without initiating an observable change in the position of the closure me

26、mber. 3.48 dead end shut off: a nonstandard term used to refer to control valve leakage. Refer to ANSI/FCI 70-2 for specification of leakage classifications. 3.49 diaphragm valve: see “weir-type body.“ 3.50 direct acting valve: a valve that travels to the closed position when the signal increases. 3

27、.51 disk: a circular shaped closure member used to modify the flow rate with either linear or rotary motion. 3.52 disk valve: a valve with a closure member consisting of a disk that moves with a rotary or linear motion against a stationary disk, each disk having flow passages through it. 3.53 downst

28、ream seating: seating assisted by pressure differential across the closure member in the closed position, moving the closure member slightly downstream into tighter contact with the seat ring seal that is supported by the body. 3.54 drift: an undesired change in the output/input relationship over a

29、period of time. 3.55 drip tight: a nonstandard term used to refer to control valve leakage. Refer to ANSI/FCI 70-2 for specification of leakage classifications. 3.56 drop tight: a nonstandard term used to refer to control valve leakage. Refer to ANSI/FCI 70-2 for specification of leakage classificat

30、ions. ANSI/ISA-75.05.01-2016 -18- 3.57 dual sealing valve: a valve that uses a resilient seating material for the primary seal and a metal-to-metal seat for a secondary seal. 3.58 dynamic unbalance: the net force/torque produced on the valve stem/shaft by fluid pressure acting on the closure member

31、and stem/shaft at stated travel and flowing conditions. 3.59 end connection: the configuration provided to make a connection with the pipe. 3.59.1 flanged: valve end connections incorporating flanges that mate with corresponding flanges on the piping. 3.59.2 split clamp: valve end connections of var

32、ious proprietary designs using split clamps to apply gasket or mating surface loading. 3.59.3 threaded: valve end connections incorporating threads, either male or female. 3.59.4 welded: valve end connections that have been prepared for welding to the line pipe or other fittings. May be butt weld (B

33、WE), or socket weld (SWE). 3.60 end-to-end dimension: a nonstandard control valve term. See “face-to-face dimension.“ 3.61 environment: ambient conditions (including temperature, pressure, humidity, radioactivity, and corrosiveness of the atmosphere) surrounding the valve and actuator. Also, the mec

34、hanical and seismic vibration transmitted through the piping or heat radiated toward the actuator from the valve body. 3.62 erosion-resistant trim: valve trim that has been designed with special surface materials or geometry to resist the erosive effects of the fluid flow. 3.63 extension bonnet: a b

35、onnet with a packing box that is extended above the usual height so as to maintain the temperature of the packing within its operating limits. 3.64 face-to-face dimension: the dimension from the face of the inlet opening to the face of the outlet opening of a valve. 3.65 flange facing: the finish on

36、 the end connection that mates with gasket surfaces. 3.66 failure mode: the position to which the valve closure member moves when the actuating energy source fails. 3.66.1 fail-closed: a condition wherein the valve closure member moves to a closed position when the actuating energy source fails. 19

37、ANSI/ISA-75.05.01-2016 3.66.2 fail-in-place: a condition wherein the valve closure member stays in its last position when the actuating energy source fails. 3.66.3 fail-open: a condition wherein the valve closure member moves to an open position when the actuating energy source fails. 3.66.4 fail-sa

38、fe: a characteristic of a particular valve and its actuator that upon loss of actuating energy supply will cause a valve closure member to be fully closed, fully open, or remain in the last position, whichever position is defined as necessary to protect the process. Fail-safe action may involve the

39、use of auxiliary controls connected to the actuator. 3.67 flangeless control valve: a valve without integral line flanges, that is installed by bolting between companion flanges, with a set of bolts or studs, generally extending through the companion flanges. 3.68 flow characteristic: an indefinite

40、term. (See below “inherent flow“ and “installed flow.“) 3.68.1 equal percentage characteristic: an inherent flow characteristic that, for equal increments of rated travel, will ideally give equal percentage changes of the flow coefficient (Cv or Kv). 3.68.2 inherent flow characteristic: the relation

41、ship between the flow rate and the closure member travel as it is moved from the closed position to rated travel with constant pressure drop across the valve. 3.68.3 installed flow characteristic: the relationship between the flow rate and the closure member travel as it is moved from the closed pos

42、ition to rated travel as the pressure drop across the valve is influenced by the varying process conditions. 3.68.4 linear characteristic: an inherent flow characteristic that can be represented by a straight line on a rectangular plot of flow coefficient (Cv or Kv) versus rated travel. Therefore, e

43、qual increments of travel provide equal increments of flow coefficient (Cv or Kv). 3.68.5 modified parabolic characteristic: an inherent flow characteristic that provides equal percent characteristic at low closure member travel and approximately a linear characteristic for upper portions of closure

44、 member travel. 3.68.6 quick opening characteristic: an inherent flow characteristic in which a maximum flow coefficient is achieved with minimal closure member travel. 3.69 flow coefficient (CV & KV): a constant related to the geometry of a valve, for a given valve travel, that establishes flow cap

45、acity. 3.70 globe valve: a valve with a linear motion closure member whose seal is perpendicular to the stem motion, one or more ports, and a body distinguished by a globular shaped cavity around the port region. (See Figure 4a.) ANSI/ISA-75.05.01-2016 -20- 3.71 guides, closure member: the means by

46、which the closure member is aligned with the seat and held stable throughout its travel. The guide is held rigidly in the body, bonnet, and/or bottom flange. 3.72 hand jack: a manual hydraulic or mechanical override device, using a lever, to stroke a valve or to limit its travel. 3.73 handwheel: a m

47、echanical manual override device, using a rotary wheel, to stroke a valve or to limit its travel. 3.74 hard facing: a material applied to valve internals to resist fluid erosion and/or to reduce the chance of galling between moving parts, particularly at high temperatures. 3.75 hard plating: a thin

48、metal deposit, sometimes electroplated, used to provide a surface coating. Hard plating is many orders of magnitude thinner than hard facing. 3.76 hysteresis: the maximum difference in output value for any single input value during a calibration cycle, excluding errors due to dead band. This differe

49、nce is sometimes called hysteretic error. See ANSI/ISA-51.1-1979 (R1993), Process Instrumentation Terminology. 3.77 hysteresis plus dead band: the maximum difference for the same input between the upscale and downscale output values during a full range traverse in each direction. This is the summation of hysteresis and dead band. 3.78 identification plate: a less preferred term. See “nameplate.“ 3.79 in-line valve: a valve having a closure member that moves to seat axially in the direction of the flow path. In-line valves are normally operated by a fluid energy