1、Industrial-process control valvesPart 2-4: Flow capacity Inherent flow characteristics and rangeabilityBS EN 60534-2-4:2009National forewordThis British Standard is the UK implementation of EN 60534-2-4:2009. It isidentical to IEC 60534-2-4:2009.The UK participation in its preparation was entrusted
2、by Technical CommitteeGEL/65, Measurement and control, to Subcommittee GEL/65/2, Elements ofsystems.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport to include all the necessary provisions of acontract. Users are respo
3、nsible for its correct application. BSI 2010ISBN 978 0 580 60150 7ICS 23.060.40; 25.040.40Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of the StandardsPolicy and Strategy Committee on 31 May 2010.Amendments is
4、sued since publicationAmd. No. Date Text affectedBRITISH STANDARDBS EN 60534-2-4:2009EUROPEAN STANDARD EN 60534-2-4 NORME EUROPENNE EUROPISCHE NORM June 2009 CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektro
5、technische Normung Central Secretariat: Avenue Marnix 17, B - 1000 Brussels 2009 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 60534-2-4:2009 E ICS 23.060.40; 25.040.40 English version Industrial-process control valves - Part 2-
6、4: Flow capacity - Inherent flow characteristics and rangeability (IEC 60534-2-4:2009) Vannes de rgulation des processus industriels - Partie 2-4: Capacit dcoulement - Caractristiques intrinsques de dbit et coefficient intrinsque de rglage (CEI 60534-2-4:2009) Stellventile fr die Prozessregelung - T
7、eil 2-4: Durchflusskapazitt - Inhrente Durchflusskennlinien und Stellverhltnis (IEC 60534-2-4:2009) This European Standard was approved by CENELEC on 2009-06-01. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Stan
8、dard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CENELEC member. This European Standard exists in three official versions (English, Fre
9、nch, German). A version in any other language made by translation under the responsibility of a CENELEC member into its own language and notified to the Central Secretariat has the same status as the official versions. CENELEC members are the national electrotechnical committees of Austria, Belgium,
10、 Bulgaria, Cyprus, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. EN 60534-2-4:2
11、009 2 Foreword The text of document 65B/704/FDIS, future edition 2 of IEC 60534-2-4, prepared by SC 65B, Devices & process analysis, of IEC TC 65, Industrial-process measurement, control and automation, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as EN 60534-2-4 on 200
12、9-06-01. The following dates were fixed: latest date by which the EN has to be implemented at national level by publication of an identical national standard or by endorsement (dop) 2010-03-01 latest date by which the national standards conflicting with the EN have to be withdrawn (dow) 2012-06-01 A
13、nnex ZA has been added by CENELEC. _ Endorsement notice The text of the International Standard IEC 60534-2-4:2009 was approved by CENELEC as a European Standard without any modification. _ BS EN 60534-2-4:2009 3 EN 60534-2-4:2009 Annex ZA (normative) Normative references to international publication
14、s with their corresponding European publications The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
15、NOTE When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD applies. Publication Year Title EN/HD Year IEC 60534-1 2005 Industrial-process control valves - Part 1: Control valve terminology and general considerations EN 60534-1 2005 IEC 60
16、534-2-3 - 1)Industrial-process control valves - Part 2-3: Flow capacity - Test procedures EN 60534-2-3 1998 2)1)Undated reference. 2)Valid edition at date of issue. BS EN 60534-2-4:2009 4 60534-2-4 IEC:2009 INDUSTRIAL-PROCESS CONTROL VALVES Part 2-4: Flow capacity Inherent flow characteristics and r
17、angeability 1 Scope This part of IEC 60534 applies to all types of industrial-process control valves. It defines how to state typical control valve inherent flow characteristics and inherent rangeabilities. It also defines how to establish criteria for adherence to manufacturer-stated flow character
18、istics. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition or the referenced document (including any amendments) applies. IEC 60534-1:2005,
19、Industrial-process control valves Part 1: Control valve terminology and general considerations IEC 60534-2-3, Industrial-process control valves Part 2-3: Flow capacity Test procedures 3 Terms and definitions For the purposes of this document, the terms and definitions given in IEC 60534-1 and the fo
20、llowing apply. 3.1 flow coefficient (see IEC 60534-1, 4.6) 3.2 rated flow coefficient (see IEC 60534-1, 4.6.3) 3.3 relative flow coefficient () 0is the relative flow coefficient at 0 % relative travel IEC 60534-1, 4.9 modified 3.4 travel (see IEC 60534-1, 4.5.2) 3.5 rated travel (see IEC 60534-1, 4.
21、5.3) 3.6 relative travel (h) (see IEC 60534-1, 4.5.4) BS EN 60534-2-4:200960534-2-4 IEC:2009 5 3.7 nominal slope slope of the best fit line for an ideal inherent linear flow characteristic, the nominal slope is: m with hm0 = for an ideal inherent equal percentage flow characteristic, the nominal slo
22、pe is: n with =01logn 3.8 inherent flow characteristic (see IEC 60534-1, 4.9) 3.8.1 ideal inherent linear flow characteristic (see IEC 60534-1, 4.9.1) 3.8.2 ideal inherent equal percentage flow characteristic (see IEC 60534-1, 4.9.2) 3.9 inherent rangeability ratio of the largest flow coefficient (m
23、ax) to the smallest flow coefficient (min) within which the deviation from the stated inherent flow characteristic does not exceed the allowable deviation stated in Clause 7 IEC 60534-1, 4.11 modified 4 Symbols Table 1 gives an overview of the symbols used in this standard. Table 1 Symbols Symbol De
24、scription Unit Relative flow coefficient Dimensionless C Flow coefficient (Kv, Cv) Various (see IEC 60534-1) CRFlow coefficient (Kvand Cv) at rated travel Various (see IEC 60534-1) d Nominal valve diameter mm h Relative travel Dimensionless BS EN 60534-2-4:2009 6 60534-2-4 IEC:2009 5 Typical inheren
25、t flow characteristics The typical inherent flow characteristics and the values of n, m and 0 for a specific size, type and trim configuration of a control valve shall be stated by the manufacturer either graphically or in tabular form. When tabulated, specific flow coefficients shall be stated for
26、the following travel positions: at 5 %, 10 %, 20 %, and every subsequent 10 % of rated travel up to and including 100 % (see Figures 1 and 2). The manufacturer may publish flow coefficients in addition to those at the above stated travel positions. In addition, the manufacturer is encouraged to spec
27、ify the generic name of a specific flow characteristic, such as “linear“ or “equal percentage“, if applicable, following the terms and definitions of IEC 60534-1. The manufacturer shall state the largest flow coefficient that meets the criteria of Clause 7, if it is less than the rated flow coeffici
28、ent (see Figures 1 and 2). BS EN 60534-2-4:200960534-2-4 IEC:2009 7 h 0,0 100 0,1 000 1,0 000 0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1,0 DCEAB IEC 574/09 Key A tolerance band B minimum within tolerance band and slope requirements (0,025 3) C valve specimen test points D manufacturer stated characteri
29、stic E maximum within slope requirements (1,0) h relative travel relative flow Inherent rangeability of test specimen: 39,530,0251,000minmax=Figure 1 Example of an equal percentage characteristic valve specimen compared to manufacturer-stated flow characteristic BS EN 60534-2-4:2009 8 60534-2-4 IEC:
30、2009 0,00 0,10 0,20 0,30 0,40 0,50 0,60 0,70 0,80 0,90 1,00 0,00 0,10 0,20 0,30 0,40 0,50 0,60 0,70 0,80 0,90 1,00 0,00 0,01 0,02 0,00 0,04 0,06 0,08 0,10 h B DA C E F IEC 575/09 Key A tolerance band B minimum within tolerance band (0,004 1) C valve specimen test points D manufacturer stated charact
31、eristic E major deviation F maximum within slope requirements (0,89) h relative travel relative flow Inherent rangeability of test specimen: 21710,0040,89minmax=Figure 2 Example of linear characteristic valve specimen compared to manufacturer-stated flow characteristic BS EN 60534-2-4:200960534-2-4
32、IEC:2009 9 6 Inherent rangeability The stated inherent rangeability of a specific control valve is related solely to the interaction between the closure member and the flow control orifice of a valve. This given value may not be applicable when the control valve is installed. Other factors such as t
33、he positioning accuracy of the actuator or the effects of hydraulic flow resistance of associated piping should be considered when deriving the installed rangeability for a specific application. Within the range of limiting flow coefficients given in Table 2, both the flow coefficient deviation and
34、the slope deviation are applicable in determining the inherent rangeability. Outside this range (see Table 2) only the slope deviation is applicable. 7 Permissible deviations between actual and manufacturer-stated inherent flow characteristics 7.1 Flow coefficient deviations When subjected to a flow
35、 test per IEC 60534-2-3, the individual test flow coefficient shall not deviate by more than 10 (1/)0,2% from those values stated in the flow characteristic by the manufacturer. The above relationship may be used to calculate allowable deviations for relative flow coefficients from zero to 1,0. For
36、convenience, some allowable deviations calculated from this relationship are listed in Table 3. This deviation is not applicable to flow coefficients at given travel positions when the manufacturer stated flow coefficient at the same travel positions fail below the lower limits or above the upper li
37、mits given in Table 2. Table 2 Limiting values of flow coefficientsFlow coefficient Lower limit Upper limit Kv4,3 (4,0 10 -2)d2Cv5 (4,7 10 -2)d2NOTE d = valve size in mm (numerically equivalent to DN for calculation purposes). BS EN 60534-2-4:2009 10 60534-2-4 IEC:2009 Table 3 Allowable flow coeffic
38、ient deviationsRange of Rated flow coefficient % Relative flow coefficient, Allowable deviation % () Lower Upper 5 0,05 18,2 0,040 9 0,059 1 10 0,1 15,8 0,084 2 0,116 20 0,2 13,8 0,172 0,227 30 0,3 12,7 0,262 0,338 40 0,4 12,0 0,352 0,448 50 0,5 11,5 0,443 0,557 60 0,6 11,1 0,533 0,667 70 0,7 10,7 0
39、,625 0,775 80 0,8 10,4 0,717 0,883 90 0,9 10,2 0,808 0,992 100 1,0 10,0 0,900 1,10 7.2 Slope deviations The inherent flow characteristic of a control valve, when plotted from test data at the stated increments of travel, shall show no major deviations in slope. By definition, a major deviation occur
40、s when the slope of the line connecting two adjacent test points varies by more than 2 to 1 or 0,5 to 1 from the slope of a straight line drawn between flow coefficients stated by the manufacturer for the same travel positions (see Figures 1 and 2). The limiting values of flow coefficients given in Table 2 are not applicable to the slope deviation requirements. _ BS EN 60534-2-4:2009
