1、BSI Standards Publication BS ISO 7121:2016 Steel ball valves for general- purpose industrial applicationsBS ISO 7121:2016 BRITISH STANDARD National foreword This British Standard is the UK implementation of ISO 7121:2016. It supersedes BS ISO 7121:2006 which is withdrawn. The UK participation in its
2、 preparation was entrusted to Technical Committee PSE/18/1, Industrial valves, steam traps, actuators and safety devices against excessive pressure - Valves - Basic standards. A list of organizations represented on this committee can be obtained on request to its secretary. This publication does not
3、 purport to include all the necessary provisions of a contract. Users are responsible for its correct application. The British Standards Institution 2016. Published by BSI Standards Limited 2016 ISBN 978 0 580 90035 8 ICS 23.060.20 Compliance with a British Standard cannot confer immunity from legal
4、 obligations. This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 April 2016. Amendments issued since publication Date T e x t a f f e c t e dBS ISO 7121:2016 ISO 2016 Steel ball valves for general-purpose industrial applications Robinets en a
5、cier tournant sphrique pour les applications industrielles gnrales INTERNATIONAL STANDARD ISO 7121 Third edition 2016-04-15 Reference number ISO 7121:2016(E)BS ISO 7121:2016ISO 7121:2016(E)ii ISO 2016 All rights reserved COPYRIGHT PROTECTED DOCUMENT ISO 2016, Published in Switzerland All rights rese
6、rved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either IS
7、O at the address below or ISOs member body in the country of the requester. ISO copyright office Ch. de Blandonnet 8 CP 401 CH-1214 Vernier, Geneva, Switzerland Tel. +41 22 749 01 11 Fax +41 22 749 09 47 copyrightiso.org www.iso.orgBS ISO 7121:2016ISO 7121:2016(E)Foreword v Introduction vi 1 Scope .
8、 1 2 Normative references 1 3 T erms and definitions . 2 4 Pressure/temperature ratings 3 4.1 Valve rating . 3 4.2 Shell rating 3 4.3 Seat and seal rating . 3 5 Design 4 5.1 Flow passageway 4 5.2 Body 5 5.2.1 Body wall thickness . 5 5.2.2 Flanged ends 8 5.2.3 Butt-welding ends. 8 5.2.4 Socket weldin
9、g ends . 8 5.2.5 Threaded ends . 9 5.2.6 Body openings 9 5.2.7 Anti-static design . 9 5.2.8 Anti-blow-out stem .10 5.2.9 Ball-stem construction 10 5.2.10 Ball construction .10 5.2.11 Operating means .10 5.2.12 Glands .11 5.2.13 End flange facing interruptions .11 5.2.14 Shell joints 12 5.2.15 Packin
10、g gland bolting 13 6 Materials 13 6.1 Shell .13 6.2 Shell material repair 14 6.3 Trim .14 6.4 Identification plate .14 6.5 Bolting .14 6.6 Seals .14 6.7 Threaded plugs 14 7 Marking .14 7.1 Legibility 14 7.2 Body marking 14 7.3 Ring joint marking 15 7.4 Identification plate .15 7.5 Special marking fo
11、r unidirectional valves 15 8 Testing and inspection 16 8.1 Pressure tests 16 8.1.1 General.16 8.1.2 Shell test .16 8.1.3 Closure tightness test . .16 8.2 Inspection .17 8.3 Examination17 8.4 Supplementary examination 18 9 Preparation for despatch 18 ISO 2016 All rights reserved iii Contents PageBS I
12、SO 7121:2016ISO 7121:2016(E)Annex A (informative) Information t o be specified b y the pur chaser 19 Annex B (informative) Identification of v al v e parts 20 Bibliogr aph y .22 iv ISO 2016 All rights reservedBS ISO 7121:2016ISO 7121:2016(E) Foreword ISO (the International Organization for Standardi
13、zation) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to b
14、e represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. The procedures used
15、to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial rules of
16、the ISO/IEC Directives, Part 2 (see www.iso.org/directives). Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any patent rights identified
17、during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents). Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement. For an explanation on th
18、e meaning of ISO specific terms and expressions related to conformit y assessment, as well as information about ISOs adherence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following URL: www.iso.org/iso/foreword.html. The committee responsible for
19、 this document is ISO/TC 153, Valves. This third edition cancels and replaces the second edition (ISO 7121:2006), which has been technically revised with the following changes: in the scope DN 600, NPS 20 and 24, Class 800 and a note on the applicability of this Class were added; the normative refer
20、ences were updated; definitions for DN, NPS, PN and Class were added; a line for DN 600 was added in Table 2; a line for DN 600 and a column for Class 800 were added in Table 3; a column for DN 600 was added in Table 4; a column for Class 800 was added in Table 6; in Tables 7 and 8, DN is up to 600;
21、 in 5.2.12.3, vertically split glands are not allowed anymore; Annex A was updated accordingly; 8.2.2 on site inspection was deleted; Annex A was updated accordingly. ISO 2016 All rights reserved vBS ISO 7121:2016ISO 7121:2016(E)Introduction The purpose of this International Standard is the establis
22、hment, in ISO format, of basic requirements and practices for flanged, butt-welding, socket welding and threaded-end steel ball valves having flow passageways identified as full bore, reduced bore and double reduced bore, suitable for general purpose applications. Flanged end Class designated valves
23、 have flanges in accordance with ASME B16.5. Flanged end PN designated valves have flanges in accordance with EN 1092-1. Valves with ends that are threaded can have threads to either ISO 7-1 or ASME B1.20.1. vi ISO 2016 All rights reservedBS ISO 7121:2016Steel ball valves for general-purpose industr
24、ial applications 1 Scope This International Standard specifies the requirements for a series of steel ball valves suitable for general-purpose industrial applications. It covers valves of the nominal sizes DN 8, 10, 15, 20, 25, 32, 40, 50, 65, 80, 100, 150, 200, 250, 300, 350, 400, 450, 500, and 600
25、 (NPS 1/4, 3/8, 1/2, 3/4, 1, 11/4, 11/2, 2, 21/2, 3, 4, 6, 8, 10, 12, 14, 16, 18, 20 and 24), and is applicable to the following pressure designations: PN 10; 16; 25; 40; 63; 100; Class 150; 300; 600; 800; 900. NOTE Valve characteristics are not necessarily available in all nominal sizes for all pre
26、ssure designations. For example, Class 800 applies only for valves with threaded end and socket weld ends up to DN 65 (NPS 21/2) and Class 900 applies only for reduced bore body seat openings. It includes provisions for valve characteristics as follows: flanged and butt-welded ends in sizes 15 DN 60
27、0 (1/2 NPS 24); socket welding ends in sizes 8 DN 100 (1/4 NPS 4); threaded ends in sizes 8 DN 50 (1/4 NPS 2); body seat openings designated as full bore, reduced bore and double reduced bore; materials; testing and inspection. 2 Normative references The following documents, in whole or in part, are
28、 normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 7-1, Pipe threads where pressure-tight joints are ma
29、de on the threads Part 1: Dimensions, tolerances and designation ISO 7-2, Pipe threads where pressure-tight joints are made on the threads Part 2: Verification by means of limit gauges ISO 228-1, Pipe threads where pressure-tight joints are not made on the threads Part 1: Dimensions, tolerances and
30、designation ISO 228-2, Pipe threads where pressure-tight joints are not made on the threads Part 2: Verification by means of limit gauges ISO 261, ISO general purpose metric screw threads General plan INTERNATIONAL ST ANDARD ISO 7121:2016(E) ISO 2016 All rights reserved 1BS ISO 7121:2016ISO 7121:201
31、6(E) ISO 965-2, ISO general purpose metric screw threads Tolerances Part 2: Limits of sizes for general purpose external and internal screw threads Medium quality ISO 4032, Hexagon regular nuts (style 1) Product grades A and B ISO 4033, Hexagon high nuts (style 2) Product grades A and B ISO 4034, He
32、xagon regular nuts (style 1) Product grade C ISO 5208, Industrial valves Pressure testing of metallic valves ISO 5209, General purpose industrial valves Marking ISO 5752, Metal valves for use in flanged pipe systems Face-to-face and centre-to-face dimensions EN 1092-1, Flanges and their joints Circu
33、lar flanges for pipes, valves, fittings and accessories, PN designated Part 1: Steel flanges EN 1515-1:1999, Flanges and their joints Bolting Part 1: Selection of bolting EN 12982, Industrial valves End-to-end and centre-to-end dimensions for butt welding end valves ASME B1.1, Unified Inch Screw Thr
34、eads, (UN and UNR Thread Form) ASME B1.20.1, Pipe Threads, General Purpose, Inch ASME B16.5, Pipe Flanges and Flanged Fittings: NPS 1/2 through NPS 24 Metric/Inch Standard ASME B16.10, Face-to-Face and End-to-End Dimensions of Valves ASME B16.34:2013, Valves Flanged, Threaded and Welding End ASME B1
35、8.2.2, Nuts for General Applications: Machine Screw Nuts, Hex, Square, Hex Flange, and Coupling Nuts (Inch Series) MSS-SP-55, 1) Quality Standard for Steel Castings for Valves, Flanges and Fittings and Other Piping Components Visual Method for Evaluation of Surface Irregularities 3 T erms a nd defin
36、iti ons For the purposes of this document, the following terms and definitions apply. 3.1 DN or NPS alphanumeric designation of size that is common for components used in a piping system, used for reference purposes, comprising the letters DN or NPS followed by a dimensionless number indirectly rela
37、ted to the physical size of the bore or outside diameter of the end connections Note 1 to entry: The number following DN or NPS does not represent a measurable value and is not used for calculation purposes except where specified in a product standard. Note 2 to entry: See ISO 6708 and ASME B16.34.
38、1) Manufacturers Standardization Society standard.2 ISO 2016 All rights reservedBS ISO 7121:2016ISO 7121:2016(E) 3.2 PN or Class alphanumeric designation for pressure-temperature rating that is common for components used in a piping system, used for reference purposes, comprising the letters “PN or
39、Class” followed by a dimensionless number indirectly related to the pressure retaining capability as a function of temperature of the component Note 1 to entry: The number following PN or Class does not represent a measurable value and is not used for calculation purposes except where specified in a
40、 product standard. There is no definitive correlation that links PN designations to Class designations. Note 2 to entry: See ISO 7268, EN 1333 and ASME B16.34. 3.3 service pressure/temperature rating lesser of the shell or seat pressure/temperature rating 3.4 anti-static design design that provides
41、for electrical continuity between the body, ball and stem of the valve 3.5 anti-blow-out design design that ensures the valve stem cannot be ejected from the body in the event of the gland being removed while the valve is under pressure 4 Pressure/temperature ratings 4.1 Valve rating The service pre
42、ssure/temperature rating applicable to valves specified in this International Standard shall be the littlest of the shell rating (4.2) or the seat rating (4.3). 4.2 Shell rating 4.2.1 The pressure/temperature ratings applicable to the valve pressure containing shell (the pressure boundary elements,
43、e.g. body, body cap, trunnion cap, cover, body inserts) shall be in accordance with that specified in the pressure/temperature tables of either ASME B16.34, Standard Class, for Class designated valves, or EN 1092-1 for PN designated valves. 4.2.2 The temperature for a corresponding shell pressure ra
44、ting is the maximum temperature that is permitted for the pressure-containing shell of the valve. In general, this maximum temperature is that of the contained fluid. The use of a pressure rating corresponding to a temperature other than that of the contained fluid is the responsibility of the user.
45、 For temperatures below, the lowest temperature listed in the pressure/temperature tables (see 4.2.1), the service pressure shall be no greater than the pressure for the lowest listed temperature. Consideration should be given to the loss of ductility and impact strength of many materials at low tem
46、perature. 4.3 Seat and seal rating 4.3.1 Non-metallic elements, for example, seat, seals or stem seals, can impose restrictions on the applied pressure/temperature rating. Any such restriction shall be shown on the valve identification plate in accordance with 7.4. 4.3.2 The design shall be such tha
47、t, when either polytetrafluoroethylene (PTFE) or reinforced PTFE is used for seats, the minimum valve pressure/temperature rating shall be as specified in Table 1. Designs ISO 2016 All rights reserved 3BS ISO 7121:2016ISO 7121:2016(E) using these seating materials having pressure/temperature ratings
48、 less than those shown in Table 1 are not in compliance with this International Standard. 4.3.3 Seat ratings for other seat materials shall be according to the manufacturers standard. However, the assigned valve service pressure/temperature rating shall not exceed that of the valve shell. Table 1 Mi
49、nimum seat pressure/temperature rating Temperature bC PTFE seats abar c Reinforced PTFE seats abar c Floating ball Trunnion Floating ball Trunnion DN 50 50 100 DN 50 DN 50 50 100 DN 50 NPS 2 2 4 NPS 2 NPS 2 2 4 NPS 2 29 to 38 69,0 51,0 19,7 51,0 75,9 51,0 19,7 51,0 50 63,6 47,1 18,2 47,1 70,4 47, 8 18,4 47, 8 75 53,3 39,2 15,2 39,2 59,9 40,4 15,6 40,4 100 43,0 31,3 12,1 31,3 49,4 33,1 12,8 33,1 125 32,7 23,3 9,1 23,3 38,9 25,8 10,0 25
