ISO 21013-2:2025

International
Standard
ISO 21013-2
Second edition
Cryogenic vessels — Pressure-relief
2025-04
accessories for cryogenic service —
Part 2:
Non-reclosable pressure-relief
devices
Récipients cryogéniques — Dispositifs de sécurité pour le service
cryogénique —
Partie 2: Dispositifs de sécurité non refermables
Reference number
© ISO 2025
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ii
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Requirements . 2
4.1 General .2
4.2 Design .2
4.2.1 Design temperature .2
4.2.2 Coincident temperature .2
4.2.3 Sublimating fluid service .3
4.2.4 Inserts .3
4.3 Materials .3
4.3.1 General .3
4.3.2 Metallic materials .3
4.3.3 Non-metallic materials .3
4.3.4 Corrosion resistance .3
4.3.5 Gas/material compatibility .4
5 Testing. 4
5.1 Type approval of bursting-disc holders .4
5.2 Production testing .4
5.2.1 Pressure and operational tests .4
5.2.2 Additional tests for pressure-relief devices with non-replaceable bursting-disc
assemblies .4
6 Cleanliness . 4
7 Burst pressure tolerances . 5
8 Marking . . 5
9 Prevention of substitution . 5
Bibliography . 6

iii
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
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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).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
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Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 220, Cryogenic vessels.
This second edition cancels and replaces the first edition (ISO 21013-2:2007), which has been technically
revised. It also incorporates the Amendment ISO 21013-2:2007/Amd. 1:2018.
The main changes are as follows:
— deletion of 4.3.5.3 because acetylene is not stored in cryogenic liquid state.
A list of all parts in the ISO 21013 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

iv
International Standard ISO 21013-2:2025(en)
Cryogenic vessels — Pressure-relief accessories for cryogenic
service —
Part 2:
Non-reclosable pressure-relief devices
1 Scope
This document specifies the requirements for the design, manufacture and testing of non-reclosable
pressure-relief devices for cryogenic service, i.e. for operation with cryogenic fluids in addition to operation
at temperatures from ambient to cryogenic.
This document is restricted to bursting-disc and buckling-pin devices not exceeding a nominal diameter
size (DN) of 200 that are designed to relieve single-phase vapours or gases. A bursting-disc or buckling-pin
assembly can be specified, constructed and tested such that it is suitable for use with more than one gas or
with mixtures of gases.
NOTE This document does not provide methods for determining the capacity of bursting-disc or buckling-pin
devices for a particular cryogenic vessel. Such methods are provided in ISO 21013-3.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements 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.
ISO 4126-2, Safety devices for protection against excessive pressure — Part 2: Bursting disc safety devices
ISO 21010, Cryogenic vessels — Gas/material compatibility
ISO 21028-1, Cryogenic vessels — Toughness requirements for materials at cryogenic temperature — Part 1:
Temperatures below -80 °C
ISO 21028-2, Cryogenic vessels — Toughness requirements for materials at cryogenic temperature — Part 2:
Temperatures between ‒80 °C and ‒20 °C
ISO 23208, Cryogenic vesse
...