SIST EN ISO 28921-2:2017

SLOVENSKI STANDARD
01-maj-2017
1DGRPHãþD
SIST EN 12567:2001
Industrijski ventili - Zapirni ventili za uporabo pri nizki temperaturi - 2. del:
Preskušanje tipa (ISO 28921-2:2015)
Industrial valves - Isolating valves for low-temperature applications - Part 2: Type testing
(ISO 28921-2:2015)
Robinetterie industrielle - Robinets d'isolement pour application à basses températures -
Partie 2: Essais de type (ISO 28921-2:2015)
Ta slovenski standard je istoveten z: EN ISO 28921-2:2017
ICS:
23.060.01 Ventili na splošno Valves in general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 28921-2
EUROPEAN STANDARD
NORME EUROPÉENNE
February 2017
EUROPÄISCHE NORM
ICS 23.060.01 Supersedes EN 12567:2000
English Version
Industrial valves - Isolating valves for low-temperature
applications - Part 2: Type testing (ISO 28921-2:2015)
Robinetterie industrielle - Robinets d'isolement pour Industriearmaturen - Absperrventile für die
application à basses températures - Partie 2: Essais de Anwendung im Niedertemperaturbereich - Teil 2:
type (ISO 28921-2:2015) Typprüfung (ISO 28921-2:2015)
This European Standard was approved by CEN on 10 January 2017.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard 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 CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2017 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 28921-2:2017 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
The text of ISO 28921-2:2015 has been prepared by Technical Committee ISO/TC 153 “Valves” of the
International Organization for Standardization (ISO) and has been taken over as EN ISO 28921-2:2017
by Technical Committee CEN/TC 69 “Industrial valves” the secretariat of which is held by AFNOR.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by August 2017, and conflicting national standards shall
be withdrawn at the latest by August 2017.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent
rights.
EN ISO 28921-1 and EN ISO 28921-2 supersede EN 12567:2000.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
Endorsement notice
The text of ISO 28921-2:2015 has been approved by CEN as EN ISO 28921-2:2017 without any
modification.
INTERNATIONAL ISO
STANDARD 28921-2
First edition
2015-11-01
Industrial valves — Isolating valves for
low-temperature applications —
Part 2:
Type testing
Robinetterie industrielle — Robinets d’isolement pour application à
basses températures —
Partie 2: Essais de type
Reference number
ISO 28921-2:2015(E)
©
ISO 2015
ISO 28921-2:2015(E)
© ISO 2015, Published in Switzerland
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
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copyright@iso.org
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ii © ISO 2015 – All rights reserved

ISO 28921-2:2015(E)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Test conditions . 2
4.1 Valve selection . 2
4.2 Testing criteria and selection of valve design . 2
4.2.1 General. 2
4.2.2 Representative valve design selection. 3
4.2.3 Selection and qualification of sealing elements . 3
4.3 Requirements for test valve, direction for installation and conditions . 3
4.4 Preparation for low temperature test . 3
4.4.1 General. 3
4.4.2 Valve tests . 3
4.4.3 Test equipment . 3
5 Low temperature testing requirements . 4
5.1 Safety provisions . 4
5.2 Cooling of the valve . 4
5.3 Test gas . 4
5.4 Equipment . 4
5.4.1 General. 4
5.4.2 Test equipment . 6
5.4.3 Instruments calibration . 6
6 Information to be supplied by the purchaser. 6
Annex A (normative) Test procedure for type testing of valves at low temperature .7
Annex B (informative) Information to be supplied by the purchaser .13
Annex C (informative) Low-temperature type test record .14
Bibliography .18
ISO 28921-2:2015(E)
Foreword
ISO (the International Organization for Standardization) 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 be 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 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 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 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 the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO’s adherence to the WTO principles in the Technical
Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information
The committee responsible for this document is Technical Committee ISO/TC 153, Valves, Subcommittee
SC 1, Design, manufacture, marking and testing.
ISO 28921 consists of the following parts, under the general title Industrial valves — Isolating valves for
low-temperature applications:
— Part 1: Design, manufacturing and production testing
— Part 2: Type testing
iv © ISO 2015 – All rights reserved

INTERNATIONAL STANDARD ISO 28921-2:2015(E)
Industrial valves — Isolating valves for low-temperature
applications —
Part 2:
Type testing
WARNING — Persons using this International Standard should be familiar with normal
laboratory practice. This International Standard does not purport to address all of the safety
issues, if any, associated with its use. It is the responsibility of the user to establish appropriate
safety and health practices and to ensure compliance with any national regulatory requirements.
1 Scope
This part of ISO 28921 specifies requirements for the type testing of isolating valves for low-temperature
applications to verify the performance of valves at a low temperature from – 50 °C down to – 196 °C.
NOTE Nominal sizes (DN), nominal pipe sizes (NPS), nominal pressure (PN) and Classes are covered in
ISO 28921-1.
This part of ISO 28921 does not evaluate valve actuators unless they are integral part of the valve.
Valves during testing can be operated manually or an actuator can be used during the testing. The effect
of cold gas vapours during testing is
...