《07-30170626-DC.pdf》由会员分享，可在线阅读，更多相关《07-30170626-DC.pdf（10页珍藏版）》请在三一文库上搜索。
1、a Date: 20 August 2007 Origin: International Latest date for receipt of comments: 30 November 2007 Project no.: 2007/02284 Responsible committee: GEL/65/2 Elements of systems Interested committees: Title: Draft BS EN 60534-2-4 ED.2 Industrial-Process Control Valves - Part 2: Flow capacity - Section
2、4: Inherent flow characteristics and rangeability Supersession information: If this document is published as a standard, the UK implementation of it will supersede NONE and partially supersede. NONE If you are aware of a current national standard which may be affected, please notify the secretary (c
3、ontact details below). WARNING: THIS IS A DRAFT AND MUST NOT BE REGARDED OR USED AS A BRITISH STANDARD. THIS DRAFT IS NOT CURRENT BEYOND 30 November 2007. This draft is issued to allow comments from interested parties; all comments will be given consideration prior to publication. No acknowledgement
4、 will normally be sent. See overleaf for information on commenting. No copying is allowed, in any form, without prior written permission from BSI except as permitted under the Copyright, Designs and Patent Act 1988 or for circulation within a nominating organization for briefing purposes. Electronic
5、 circulation is limited to dissemination by e-mail within such an organization by committee members. Further copies of this draft may be purchased from BSI Customer Services, Tel: +44(0) 20 8996 9001 or email ordersbsi-. British, International and foreign standards are also available from BSI Custom
6、er Services. British Standards on CD or Online are available from British Standards Publishing Sales Limited. Tel: 01344 404409 or email bsonlinetechindex.co.uk. Information on the co-operating organizations represented on the committees referenced above may be obtained from the responsible committe
7、e secretary. Cross-references The British Standards which implement International or European publications referred to in this draft may be found via the British Standards Online Service on the BSI web site http:/www.bsi-. Direct tel: 020 8996 7205 Responsible Committee Secretary: Mr A Ashrafi (BSI)
8、 E-mail: asghar.ashrafibsi- Draft for Public Comment Head Office 389 Chiswick High Road London W4 4AL Telephone: +44(0)20 8996 9000 Fax: +44(0)20 8996 7001 Form 36 Version 7.0 DPC: 07/30170626 DC Licensed Copy: London South Bank University, London South Bank University, Sat Sep 01 03:12:51 GMT+00:00
9、 2007, Uncontrolled Copy, (c) BSI b Introduction This draft standard is based on international discussions in which the UK has taken an active part. Your comments on this draft are welcome and will assist in the preparation of the consequent standard. If no comments are received to the contrary, the
10、n the UK will approve this draft. There is a high probability that this text could be adopted by CENELEC as a reference document for harmonization or as a European Standard. Recipients of this draft are requested to comment on the text bearing in mind this possibility. UK Vote Please indicate whethe
11、r you consider the UK should submit a negative (with reasons) or positive vote on this draft. Submission The guidance given below is intended to ensure that all comments receive efficient and appropriate attention by the responsible BSI committee. Annotated drafts are not acceptable and will be reje
12、cted. All comments must be submitted, preferably electronically, to the Responsible Committee Secretary at the address given on the front cover. Comments should be compatible with Version 6.0 or Version 97 of Microsoft Word for Windows, if possible; otherwise comments in ASCII text format are accept
13、able. Any comments not submitted electronically should still adhere to these format requirements. All comments submitted should be presented as given in the example below. Further information on submitting comments and how to obtain a blank electronic version of a comment form are available from the
14、 BSI web site at: http:/www.bsi- Template for comments and secretariat observations Date: xx/xx/200x Document: ISO/DIS xxxxx 1 2 (3) 4 5 (6) (7) MB Clause No./ Subclause No./ Annex (e.g. 3.1) Paragraph/ Figure/Table/ Note (e.g. Table 1) Type of com- ment Comment (justification for change) by the MB
15、Proposed change by the MB Secretariat observations on each comment submitted 3.1 Definition 1 ed Definition is ambiguous and needs clarifying. Amend to read . so that the mains connector to which no connection . 6.4 Paragraph 2 te The use of the UV photometer as an alternative cannot be supported as
16、 serious problems have been encountered in its use in the UK. Delete reference to UV photometer. Microsoft and MS-DOS are registered trademarks, and Windows is a trademark of Microsoft Corporation. Licensed Copy: London South Bank University, London South Bank University, Sat Sep 01 03:12:51 GMT+00:
17、00 2007, Uncontrolled Copy, (c) BSI FORM CDV (IEC) 2005-09-23 65B/640/CDV COMMITTEE DRAFT FOR VOTE (CDV) PROJET DE COMIT POUR VOTE (CDV) Project number IEC 60534-2-4/Ed.2 Numro de projet IEC/TC or SC: 65B CEI/CE ou SC: Secretariat / Secrtariat U.S.A/Etats-Unis Submitted for parallel voting in CENELE
18、C Soumis au vote parallle au CENELEC Date of circulation Date de diffusion 2007-08-17 Closing date for voting (Voting mandatory for P-members) Date de clture du vote (Vote obligatoire pour les membres (P) 2008-01-18 Also of interest to the following committees Intresse galement les comits suivants S
19、upersedes document Remplace le document 65B/605/MCR Functions concerned Fonctions concernes Safety Scurit EMC CEM Environment Environnement Quality assurance Assurance qualit CE DOCUMENT EST TOUJOURS LTUDE ET SUSCEPTIBLE DE MODIFICATION. IL NE PEUT SERVIR DE RFRENCE. LES RCIPIENDAIRES DU PRSENT DOCU
20、MENT SONT INVITS PRSENTER, AVEC LEURS OBSERVATIONS, LA NOTIFICATION DES DROITS DE PROPRIT DONT ILS AURAIENT VENTUELLEMENT CONNAISSANCE ET FOURNIR UNE DOCUMENTATION EXPLICATIVE. THIS DOCUMENT IS STILL UNDER STUDY AND SUBJECT TO CHANGE. IT SHOULD NOT BE USED FOR REFERENCE PURPOSES. RECIPIENTS OF THIS
21、DOCUMENT ARE INVITED TO SUBMIT, WITH THEIR COMMENTS, NOTIFICATION OF ANY RELEVANT PATENT RIGHTS OF WHICH THEY ARE AWARE AND TO PROVIDE SUPPORTING DOCUMENTATION. Titre : CEI 60534-2-4 : Vannes de rgulation des processus industriels - Partie 2-4: Capacit dcoulement - Caractristiques intrinsques de dbi
22、t et coefficient intrinsque de rglage Title : IEC 60534-2.4: Industrial-Process Control Valves - Part 2-4: Flow Capacity - Inherent flow characteristics and rangeability Note dintroduction Introductory note The National Committees are requested to note that for this publication the maintenance resul
23、t date is 2013. ATTENTION VOTE PARALLLE CEI CENELEC Lattention des Comits nationaux de la CEI, membres du CENELEC, est attire sur le fait que ce projet de comit pour vote (CDV) de Norme internationale est soumis au vote parallle. Un bulletin de vote spar pour le vote CENELEC leur sera envoy par le S
24、ecrtariat Central du CENELEC. ATTENTION IEC CENELEC PARALLEL VOTING The attention of IEC National Committees, members of CENELEC, is drawn to the fact that this Committee Draft for Vote (CDV) for an International Standard is submitted for parallel voting. A separate form for CENELEC voting will be s
25、ent to them by the CENELEC Central Secretariat. Copyright 2007 International Electrotechnical Commission, IEC. All rights reserved. It is permitted to download this electronic file, to make a copy and to print out the content for the sole purpose of preparing National Committee positions. You may no
26、t copy or “mirror“ the file or printed version of the document, or any part of it, for any other purpose without permission in writing from IEC. Licensed Copy: London South Bank University, London South Bank University, Sat Sep 01 03:12:51 GMT+00:00 2007, Uncontrolled Copy, (c) BSI 60534-2-4/Ed.2 CD
27、V IEC:200X 2 INDUSTRIAL-PROCESS CONTROL VALVES Part 2: Flow Capacity Section 4: Inherent flow characteristics and rangeability 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 inh
28、erent rangeabilities. It also defines how to establish criteria for adherence to manufacturer-stated flow characteristics. 2 Normative references The following normative documents contain provisions which, through reference in this text, constitute provisions of this part of IEC 60534. For dated ref
29、erences, subsequent amendments to, or revisions of, any of these publication do not apply. However, parties to agreements based on this part of IEC 60534 are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated referen
30、ces, the latest edition of the normative document referred to applies. Members of IEC and ISO maintain registers of currently valid International Standards. IEC 60534 (all parts), Industrial-process control valves 3 Definitions For the purpose of this part of IEC 60534, definitions given in IEC 6053
31、4-1 and the following apply. 3.1 flow coefficient (see IEC 60534-1) 3.2 rated flow coefficient (see IEC 60534-1) 3.3 relative flow coefficient ( ) (see IEC 60534-1.) 0 is the relative flow coefficient at 0% relative travel. 3.4 travel (see IEC 60534-1) 3.5 rated travel (see IEC 60534-1) 3.6 relative
32、 travel (h) (see IEC 60534-1) Licensed Copy: London South Bank University, London South Bank University, Sat Sep 01 03:12:51 GMT+00:00 2007, Uncontrolled Copy, (c) BSI 60534-2-4/Ed.2 CDV IEC:200X 3 3.7 nominal slope the slope of the best fit line for a linear characteristic : m with h m 0 = for an e
33、qual percentage characteristic : n with = 0 1 logn 3.8 inherent flow characteristic (see IEC 60534-1) 3.8.1 ideal inherent linear flow characteristic (see IEC 60534-1) 3.8.2 ideal inherent equal percentage flow characteristic (see IEC 60534-1) 3.9 inherent rangeability (see IEC60534-1.) The ratio of
34、 the largest flow coefficient (max) 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 5. 4 Symbols Symbol Description Unit Relative flow coefficient Dimensionless C Flow coefficient
35、(Kv, Cv) Various (see IEC 60534-1) CR Flow coefficient (Kv and Cv) at rated travel Various (see IEC 60534-1) d Nominal valve diameter mm h Relative travel Dimensionless 5 Typical inherent flow characteristics The typical inherent flow characteristics and the values of n and 0 for a specific size, ty
36、pe 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 the following travel positions: at 5%, 10%, 20%, and every subsequent 10% of rated travel up to and including 100% (s
37、ee Figures 1 and 2). The manufacturer may publish flow coefficients in addition to those at the above stated travel positions. Licensed Copy: London South Bank University, London South Bank University, Sat Sep 01 03:12:51 GMT+00:00 2007, Uncontrolled Copy, (c) BSI 60534-2-4/Ed.2 CDV IEC:200X 4 In ad
38、dition, the manufacturer is encouraged to specify the generic name of a specific flow characteristic, such as “Linear“ or “Equal-Percentage“, if applicable, following the definitions of IEC 60534-1. The manufacturer shall state the largest flow coefficient that meets the criteria of Clause 7, if it
39、is less than the rated flow coefficient (see Figure 2). 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 contro
40、l valve is installed. Other factors such as the 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 Tabl
41、e 1, both the flow coefficient deviation and the slope deviation are applicable in determining the inherent rangeability. Outside this range (see Table1) only the slope deviation is applicable. 7 Permissible deviations between actual and manufacturer-stated inherent flow characteristics 7.1 Flow coe
42、fficient deviations When subjected to a flow 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 rela
43、tive flow coefficients from zero to 1,0. For convenience, some allowable deviations calculated from this relationship are listed in Table 2. This deviation is not applicable to flow coefficients at given travel positions when the manufacturer stated flow coefficient at the same travel positions fail
44、 below the lower limits or above the upper limits given in Table 1 (see Figure 3). Table 1 Limiting values of flow coefficients Flow Coefficient Lower limit Upper limit Kv 4,3 (4,0 10 -2) d2 Cv 5 (4,7 10 -2) d2 Licensed Copy: London South Bank University, London South Bank University, Sat Sep 01 03:
45、12:51 GMT+00:00 2007, Uncontrolled Copy, (c) BSI 60534-2-4/Ed.2 CDV IEC:200X 5 Table 2 Allowable flow coefficient deviations Range of Rated flow coefficient Relative flow coefficient, Allowable deviation % Lower Upper 5 0,05 18,2 0,0409 0,0591 10 0,1 15,8 0,0842 0,116 20 0,2 13,8 0,172 0,227 30 0,3
46、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 0,625 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
47、 increments of travel, shall show no major deviations in slope. By definition, a major deviation occurs 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 f
48、or the same travel positions (see Figure 2). The limiting values of flow coefficients given in Table 1 are not applicable to the slope deviation requirements as illustrated by Figure 3. Licensed Copy: London South Bank University, London South Bank University, Sat Sep 01 03:12:51 GMT+00:00 2007, Unc
49、ontrolled Copy, (c) BSI 60534-2-4/Ed.2 CDV IEC:200X 6 A = tolerance band B = minimum within tolerance band and slope requirements (0,0253) C = valve specimen test points D = manufacturer stated characteristic E = maximum within slope requirements (1,0) h = relative travel = relative flow Inherent rangeability of test spe