1、 AMERICAN NATIONAL STANDARD ANSI/ISA75.02.012008 (IEC 60534-2-3 Mod) Formerly ANSI/ISA-75.02-1996 Control Valve Capacity Test Procedures Approved 21 April 2009 ANSI/ISA-75.02.01-2008 (IEC 60534-2-3 Mod) Control Valve Capacity Test Procedures ISBN: 978-1-936007-11-0 Copyright 2008 by IEC and ISA. All
2、 rights reserved. Not for resale. Printed in the United States of America. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means (electronic mechanical, photocopying, recording, or otherwise), without the prior written permission of t
3、he Publisher. ISA 67 Alexander Drive P.O. Box 12277 Research Triangle Park, North Carolina 27709 - 3 - ANSI/ISA-75.02.01-2008 (IEC 60534-2-3 Mod) Preface This preface, as well as all footnotes and annexes, is included for information purposes and is not part of ANSI/ISA-75.02.01-2008 (IEC 60534-2-3
4、Mod). This document has been prepared as part of the service of ISA towards a goal of uniformity in the field of instrumentation. To be of real value, this document should not be static but should be subject to periodic review. Toward this end, the Society welcomes all comments and criticisms and as
5、ks that they be addressed to the Secretary, Standards and Practices Board; ISA; 67 Alexander Drive; P. O. Box 12277; Research Triangle Park, NC 27709; Telephone (919) 549-8411; Fax (919) 549-8288; E-mail: standardsisa.org. The ISA Standards and Practices Department is aware of the growing need for a
6、ttention to the metric system of units in general, and the International System of Units (SI) in particular, in the preparation of instrumentation standards. The Department is further aware of the benefits to USA users of ISA standards of incorporating suitable references to the SI (and the metric s
7、ystem) in their business and professional dealings with other countries. Toward this end, this Department will endeavor to introduce SI-acceptable metric units in all new and revised standards, recommended practices, and technical reports to the greatest extent possible. Standard for Use of the Inte
8、rnational System of Units (SI): The Modern Metric System, published by the American Society for Testing b) test section; c) throttling valves; d) flow-measuring device; e) pressure taps; and f) temperature sensor. Figure 1 Basic flow test system 4.2 Test specimen The test specimen is any valve or co
9、mbination of valve, pipe reducer, and expander or other devices attached to the valve body for which test data are required. See Annex B for additional examples of test specimens representative of typical field installations. Additional considerations apply when testing certain styles of control val
10、ves. (1) Fractional C (Cv, Kv) valves (valves where C 0.87. See Annex E for a more detailed “long form” procedure. NOTE Values of upstream pressure and pressure differential used in this procedure are those values measured at the pressure taps. 6.2.3 The following data shall be recorded using the pr
11、ovisions in Clause 4: a) Valve travel b) Upstream pressure (P1) c) Differential pressure (P) across test section pressure taps d) Volumetric flow rate (Q) e) Fluid temperature f) Barometric pressure g) Physical description of test specimen (i.e., type of valve, flow direction, etc.) h) Physical desc
12、ription of test system and test fluid i) Any deviation from the provisions of this standard 6.3 Piping geometry factor, FP, test procedure The piping geometry factor, FP, modifies the valve sizing coefficient for reducers or other devices attached to the valve body that are not in accord with the te
13、st section. It is the ratio of the installed C (Cv, Kv) with these reducers or other devices attached to the valve body to the rated C (Cv, Kv) of the - 23 - ANSI/ISA-75.02.01-2008 (IEC 60534-2-3 Mod) valve installed in a standard test section and tested under identical service conditions. This fact
14、or is obtained by replacing the valve with the desired combination of valve, reducers, and/or other devices and then conducting the flow test outlined in 6.1, treating the combination of the valve and reducers as the test specimen for the purpose of determining test section line size. For example, a
15、 100-mm (4-in.) valve between reducers in a 150-mm (6-in.) line would use pressure tap locations based on 150-mm (6-in.) nominal diameter. The data evaluation procedure is provided in 7.3. 6.4 Combination (product) of liquid pressure recovery factor FLand piping geometry factor FP, FLPtest procedure
16、 Perform the tests outlined for FLin 6.2, replacing the valve with the desired combination of valve and pipe reducers or other devices and treating the combination of valve and reducers as the test specimen. The data evaluation procedure is provided in 7.4. 6.5 Reynolds Number factor, FR, test proce
17、dure To produce values of the Reynolds Number factor, FR, nonturbulent flow conditions must be established through the test valve. Such conditions will require low pressure differentials, high viscosity fluids, small values of C (Cv, Kv) or some combination of these. With the exception of valves wit
18、h very small values of C (Cv, Kv) turbulent flow will always exist when flowing tests are performed in accordance with the procedure outlined in 5.1, and FRunder these conditions will have the value of 1.0. Determine values of FRby performing flowing tests with the valve installed in the standard te
19、st section without reducers or other devices attached. These tests shall follow the procedure for C (Cv, Kv) determination except that a) test pressure differentials may be any appropriate values provided that no vaporization of the test fluid occurs within the test valve; b) minimum upstream test p
20、ressure values shown in Table 2 may not apply if the test fluid is not fresh water at 20 C 14 C (68 F 25 F); and c) the test fluid shall be a Newtonian fluid having a viscosity considerably greater than water unless instrumentation is available for accurately measuring very low pressure differential
21、s. Perform a sufficient number of these tests at each selected valve travel by varying the pressure differential across the valve so that the entire range of conditions, from turbulent to laminar flow, is spanned. The data evaluation procedure is provided in 7.5. 6.6 Liquid critical pressure ratio f
22、actor, FF, test procedures The liquid critical pressure ratio factor, FF, is ideally a property of the fluid and its temperature. It is the ratio of the apparent vena contracta pressure at choked flow conditions to the vapor pressure of liquid at inlet temperature. The quantity of FFmay be determine
23、d experimentally, although it is not possible to evaluate FF, C and FLconcurrently. A test specimen for which FLand C (Cv, Kv) have been previously established by test in a system utilizing known fluid properties is required. The standard test section without reducers or other devices attached will
24、be used with the test specimen installed. The test procedure outlined in 6.2 for obtaining Qmaxwill be used with the fluid of interest as the test fluid. The data evaluation procedure is in 7.6. ANSI/ISA-75.02.01-2008 (IEC 60534-2-3 Mod)- 24 - PNQ= Co117 Data evaluation procedure incompressible flui
25、ds The following procedures are to be used for the evaluation of the data obtained using the test procedures in Clause 6. The pressure differentials used to calculate the flow coefficients and other flow factors were obtained using the test section defined in Table 1. These pressure measurements wer
26、e made at the pressure taps and include the test section piping between the taps as well as the test specimen. 7.1 C Calculation 7.1.1 Using the data obtained in 6.1, calculate C (Cv, Kv) for each test point at a given valve travel using the equation (Eq. 1) Round off the calculated value to no more
27、 than three significant digits. 7.1.2 The flow coefficient C (Cv, Kv) of the valve is the arithmetic average of the calculated values at each travel tested as obtained from the test data in 6.1.5. The individual values used in computing the average value should fall within 2.5% of the average value.
28、 The “rated C“ is the flow coefficient at 100% rated travel. 7.2 FLCalculation Calculate FLas follows: (Eq. 2) ()ovFPF - PCNQ= FL111maxwhere P1is the pressure at the upstream pressure tap for the Qmaxdetermination (see 6.2). If fresh water at 5 to 40 C ( 41 to 104 F) is used FFhas a value of 0.96. I
29、f fresh water is not used, FFfor that fluid shall be used2. 7.3 FPCalculation Calculate FPas follows: (Eq. 3) oPPCNQ= F112If the test fluid is a single component fluid it is permissible to use cvFPP280960F = . - 25 - ANSI/ISA-75.02.01-2008 (IEC 60534-2-3 Mod) 7.4 FLPCalculation Calculate FLPas follo
30、ws: (Eq. 4) ovFmaxLPPFPCNQ= F111where P1is the pressure at the upstream pressure tap for the Qmaxdetermination (see 6.2). 7.5 FRCalculation Use test data, obtained as described under 6.5 and in Equation (1) in 7.1 to obtain values of an apparent C (Cv, Kv). This apparent C (Cv, Kv) is equivalent to
31、FRCv. Therefore, FRis obtained by dividing the apparent C (Cv, Kv) by the experimental value of C (Cv, Kv) determined for the test valve under standard conditions at the same valve travel. Although data may be correlated in any manner suitable to the experimenter, a method that has proven to provide
32、 satisfactory correlations involves the use of the valve Reynolds Number, which may be calculated from (Eq. 5) 41422241Re+DNCFCFQFN= LLdvwhere Fd= valve style modifier, accounts for the effect of geometry on Reynolds Number (see Annex C for additional discussion). v = kinematic viscosity in centisto
33、kes. Plotting values of FRversus Revwill result in the curve that appears as Figure 3 a & b in ANSI/ISA-75.01.01 (IEC 60534-2-1 Mod)-2007, Flow Equations for Sizing Control Valves. 7.6 FFCalculation Using the data obtained in accord with 6.6 calculate FFas follows: (Eq. 6) =21max111CFNQPPFLovFwhere
34、Pvis the fluid vapor pressure at the inlet temperature. 8 Test procedure compressible fluids The following instructions are given for the performance of various tests using compressible fluids. The procedures for data evaluation of these tests follow in Clause 9. ANSI/ISA-75.02.01-2008 (IEC 60534-2-
35、3 Mod)- 26 - 8.1 C Test procedure The determination of the flow coefficient, C (Cv, Kv) requires flow tests using the following procedure to obtain the necessary test data. The data evaluation procedure is in 9.1. An alternative procedure for calculating C (Cv, Kv) is provided in 8.3. 8.1.1 Install
36、the test specimen without reducers or other devices in accordance with the piping requirements in Table 1. 8.1.2 Flow tests will include flow measurements at three pressure differentials. In order to approach flowing conditions that can be assumed to be incompressible, the pressure drop ratio (x = P
37、/P1) shall be 0.02. It is also necessary to ensure that the flowing conditions are operating n the fully turbulent flow regime. A minimum valve Reynolds Number of 100,000 should be established for all test conditions (see Equation 5). Note that actual volumetric flow rate should be used in computing
38、 the Reynolds Number. 8.1.3 The valve flow test shall be performed at 100 percent of rated valve travel. Optional tests may be performed at 5 percent and each 10 percent of rated valve travel or any other points of interest to more fully determine the inherent characteristic of the specimen. 8.1.4 T
39、he following data shall be recorded using the provisions in Clause 4: a) Valve travel b) Upstream pressure (P1) c) Differential pressure (P) across test section pressure taps d) Volumetric flow rate (Q) e) Fluid temperature (T1) upstream of valve f) Barometric pressure g) Physical description of tes
40、t specimen (e.g., type of valve, flow direction, etc.) h) Physical description of test system and test fluid i) Any deviation from the provisions of this standard. 8.2 xTTest procedure The maximum flow rate, Qmax, (referred to as choked flow) is required in the calculation of xT, the pressure drop r
41、atio factor. This factor is the terminal ratio of the differential pressure to absolute upstream pressure (P /P1 ), for a given test specimen installed without reducers or other devices. The maximum flow rate is defined as that flow rate at which, for a given upstream pressure, a decrease in downstr
42、eam pressure will not produce an increase in flow rate. The test procedure required to obtain Qmaxis contained in this subclause with the data evaluation procedure in 9.2. An alternative procedure for determining xTis provided in 8.3. 8.2.1 Install the test specimen without reducers or other attache
43、d devices in accordance with piping requirements in Table 1. The test specimen shall be at 100 percent of rated travel. Optional tests may be done at other valve travels to more fully understand the possible variation of xTwith valve travel. - 27 - ANSI/ISA-75.02.01-2008 (IEC 60534-2-3 Mod) 8.2.2 An
44、y upstream supply pressure sufficient to produce choked flow is acceptable, as is any resulting pressure differential across the valve, provided that the criteria for determination of choked flow specified in 8.2.3 are met. 8.2.3 The downstream throttling valve will be in the wide-open position. The
45、n, with a preselected upstream pressure, the flow rate will be measured and the downstream pressure recorded. This test establishes the maximum pressure differential for the test specimen in this test system. A second test shall be conducted using the downstream throttling valve to reduce the pressu
46、re differential by 10 percent of the pressure differential determined in the first test (with the same upstream pressure). If the flow rate of this second test is within 0.5 percent of the flow rate for the first test, then the maximum flow rate has been established. In order to attain the prescribe
47、d accuracy, the flow rate instrument accuracy and repeatability requirements of 4.5 must be followed. This series of tests must be made consecutively, using the same instruments, and without alteration to the test setup. 8.2.4 The following data shall be recorded using the provisions in Clause 4: a)
48、 Valve travel b) Upstream pressure (P1) c) Differential pressure (P) across test section pressure taps d) Volumetric flow rate (Q) e) Fluid temperature upstream (T1) of valve f) Barometric pressure g) Physical description of test specimen (e.g., type of valve, flow direction, etc.) h) Physical descr
49、iption of test system and test fluid i) Any deviation from the provisions of this standard. 8.3 Alternative test procedure for C and xT8.3.1 Install the test specimen without reducers or other attached devices in accordance with piping requirements in Table 1. The test specimen shall be at 100 percent of rated travel (or at any other travel of interest). 8.3.2 With a preselected upstream pressure, P1,measurements shall be made of flow rate, Q, upstream fluid temperature, T1, differential pressure, P , for a minimum of
