EN ISO 4126-3:2020

SLOVENSKI STANDARD
01-november-2020
Nadomešča:
SIST EN ISO 4126-3:2006
Naprave za varovanje pred visokim tlakom - 3. del: Varnostni ventili in razpočne
plošče v kombinaciji (ISO/FDIS 4126-3:2020)
Safety devices for protection against excessive pressure - Part 3: Safety valves and
bursting disc safety devices in combination (ISO 4126-3:2020)
Sicherheitseinrichtungen gegen unzulässigen Überdruck - Teil 3: Sicherheitsventile und
Berstscheibeneinrichtungen in Kombination (ISO 4126-3:2020)
Dispositifs de sécurité pour protection contre les pressions excessives - Partie 3:
Soupapes de sûreté et dispositifs de sûreté à disque de rupture en combinaison (ISO
4126-3:2020)
Ta slovenski standard je istoveten z: EN ISO 4126-3:2020
ICS:
13.240 Varstvo pred previsokim Protection against excessive
tlakom pressure
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 4126-3
EUROPEAN STANDARD
NORME EUROPÉENNE
September 2020
EUROPÄISCHE NORM
ICS 13.240 Supersedes EN ISO 4126-3:2006
English Version
Safety devices for protection against excessive pressure -
Part 3: Safety valves and bursting disc safety devices in
combination (ISO 4126-3:2020)
Dispositifs de sécurité pour protection contre les Sicherheitseinrichtungen gegen unzulässigen
pressions excessives - Partie 3: Soupapes de sûreté et Überdruck - Teil 3: Sicherheitsventile und
dispositifs de sûreté à disque de rupture en Berstscheibeneinrichtungen in Kombination (ISO
combinaison (ISO 4126-3:2020) 4126-3:2020)
This European Standard was approved by CEN on 11 July 2020.

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, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, 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: Rue de la Science 23, B-1040 Brussels
© 2020 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 4126-3:2020 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
Annex ZA (informative) Relationship between this European Standard and the Essential
Requirements of EU Directive 2014/68/EU (PED) aimed to be covered . 4

European foreword
This document (EN ISO 4126-3:2020) has been prepared by Technical Committee ISO/TC 185 "Safety
devices for protection against excessive pressure" in collaboration with 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 March 2021, and conflicting national standards shall
be withdrawn at the latest by March 2021.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 4126-3:2006.
This document has been prepared under a mandate given to CEN by the European Commission and the
European Free Trade Association, and supports essential requirements of EU Directive(s).
For the relationship with EU Directive(s) see informative Annex ZA, which is an integral part of this
document.
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, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the
United Kingdom.
Endorsement notice
The text of ISO 4126-3:2020 has been approved by CEN as EN ISO 4126-3:2020 without any
modification.
Annex ZA
(informative)
Relationship between this European Standard and the Essential
Requirements of EU Directive 2014/68/EU (PED) aimed to be covered
This European Standard has been prepared under a Commission’s standardization request to provide
one voluntary means of conforming to Essential Requirements of New Approach Directive 2014/68/EU,
Pressure Equipment Directive (PED).
Once this document is cited in the Official Journal of the European Union under that Directive,
compliance with the normative clauses of this document given in Table ZA.1 confers, within the limits of
the scope of this document, a presumption of conformity with the corresponding essential
requirements of that Directive and associated EFTA regulations.
Table ZA.1 — Correspondence between this European Standard and Annex I of the Directive
2014/68/EU
Essential Requirements of Clause(s)/sub-clause(s) Remarks/Notes
Directive 2014/68/EU of this EN
Clause 2.1 5, 7, 9 and 12 General design
Clause 2.11.1 and 2.11.2 5, 6, 7, 8, 9, 11 and 12 Safety accessories
Clause 3.4 a), 1st indent 6 Installation instructions
WARNING 1 — Presumption of conformity stays valid only as long as a reference to this European
Standard is maintained in the list published in the Official Journal of the European Union. Users of this
document should consult frequently the latest list published in the Official Journal of the European
Union.
WARNING 2 — Other Union legislation may be applicable to the product(s) falling within the scope of
this document.
INTERNATIONAL ISO
STANDARD 4126-3
Second edition
2020-09
Safety devices for protection against
excessive pressure —
Part 3:
Safety valves and bursting disc safety
devices in combination
Dispositifs de sécurité pour protection contre les pressions
excessives —
Partie 3: Soupapes de sûreté et dispositifs de sûreté à disque de
rupture en combinaison
Reference number
ISO 4126-3:2020(E)
©
ISO 2020
ISO 4126-3:2020(E)
© ISO 2020
All rights reserved. Unless otherwise specified, or required in the context of its implementation, 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 ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved

ISO 4126-3:2020(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols . 4
5 Design of combination . 4
6 Installation of combination . 5
7 Combination performance . 5
8 Determination of combination discharge capacity factor, F , by testing.6
d
8.1 General . 6
8.2 Test requirements . 6
8.3 Test rig . 6
8.4 Test method . 7
8.5 Test procedure . 7
8.6 Acceptance criteria of the tests . 7
8.6.1 General. 7
8.6.2 Conditions applicable to the safety valve . 8
8.6.3 Conditions applicable to the bursting disc safety device . 8
8.6.4 Conditions applicable to combination . 8
9 Derivation of combination discharge capacity factor, F . 9
d
10 Alternative to testing for F . 9
d
11 Certification of combination discharge capacity factor, F . 9
d
12 Application and use of the certified combination discharge capacity factor, F .9
d
13 Marking and identification of combination devices . 9
13.1 Bursting disc safety device . 9
13.2 Safety valve .10
13.3 Combination .10
14 Documentation .10
15 Preparation for storage and transport .11
ISO 4126-3:2020(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 l
...