ISO 21010:2014

INTERNATIONAL ISO
STANDARD 21010
Second edition
2014-05-01
Cryogenic vessels — Gas/materials
compatibility
Récipients cryogéniques — Compatibilité gaz/matériaux
Reference number
ISO 21010:2014(E)
©
ISO 2014

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ISO 21010:2014(E)

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ISO 21010:2014(E)

Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Compatibility of materials with gases other than oxygen . 1
4 General requirements for oxygen service . 1
4.1 Evaluation of materials for oxygen service . 1
4.2 Evaluation of metallic materials . 2
4.3 Evaluation of non-metallic materials . 2
4.4 Test methods and acceptance criteria . 3
4.5 Alternative method of acceptance . 5
Annex A (informative) Metallic materials commonly used for liquid oxygen service .6
Annex B (normative) Spontaneous ignition test (bomb test) . 7
Annex C (normative) Pressure surge test .12
Bibliography .15
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ISO 21010:2014(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
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ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
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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
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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 ISO/TC 220, Cryogenic vessels.
This second edition cancels and replaces the first edition (ISO 21010:2004), which has been technically
revised.
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INTERNATIONAL STANDARD ISO 21010:2014(E)
Cryogenic vessels — Gas/materials compatibility
1 Scope
This International Standard specifies gas/materials compatibility requirements (such as chemical
resistance) for cryogenic vessels, but it does not cover mechanical properties (e.g. for low temperature
applications).
It gives general guidance for compatibility with gases and detailed compatibility requirements for
oxygen and oxygen-enriched atmospheres. This International Standard also defines the testing methods
for establishing oxygen compatibility of materials (metallic and non-metallic) to be used for cryogenic
vessels and associated equipment.
This International Standard focuses on materials that are normally with or could be in contact with
cryogenic fluids.
2 Normative references
The following documents, in whole or in part, are 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 10297:2006, Transportable gas cylinders — Cylinder valves — Specification and type testing
ISO 23208, Cryogenic vessels — Cleanliness for cryogenic service
3 Compatibility of materials with gases other than oxygen
Cryogenic vessels are used in a range of temperatures from very low temperature to ambient temperature.
On excluding oxygen, compatibility problems such as corrosion and hydrogen embrittlement normally
occur at ambient temperature and become negligible at cryogenic temperatures.
In the case of gases other than oxygen, ISO 11114-1 and ISO 11114-2 can be used as a guide for cryogenic
vessels.
4 General requirements for oxygen service
4.1 Evaluation of materials for oxygen service
4.1.1 General
The selection of a material for use with oxygen and/or in an oxygen-enriched atmosphere is primarily a
matter of understanding the circumstances that cause oxygen to react with the material. Most materials
in contact with oxygen will not ignite without a source of ignition energy. When an energy input rate, as
converted to heat, is greater than the rate of heat dissipation, and the resulting heat increase is continued
for sufficient time, ignition and combustion will occur. Thus, two things shall be considered:
— the material’s minimum ignition temperature;
— the energy sources that will produce a sufficient increase in the temperature of the material.
These should be viewed in the context of the entire system design so that the specific factors listed
below will assume proper relative significance.
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ISO 21010:2014(E)

The specific factors are:
— the properties of the materials, including the factors affecting ease of ignition and the conditions
affecting potential resultant damage (heat of reaction);
— the operating conditions: pressure, temperature, gas velocity, oxygen concentrations, and oxygen
state (gaseous or liquid) and surface contamination in accordance with ISO 23208;
— the potential sources of ignition: friction, heat of compression, heat from mass impact, heat from
particle impact, static electricity, electric arc, resonance, and internal flexing etc.;
— the reaction effect (consequences on the surroundings, etc.);
— additional factors: performance requirements, prior experience, availability, and cost.
CAUTION — This International Standard specifies the minimum acceptance requirements for
materials in oxygen and enriched air service. In the cases of severe conditions and when the
operating pressure is above 40 bar, additional tests to those specified should be considered.
4.1.2 Evaluation of the insulation system
Insulation systems for cryogenic vessels that can come into contact with oxygen or condensed enriched
air, shall be tested in accordance with 4.4.4. Any representative sample that passed the tests in 4.4.3
need not be tested in accordance with 4.4.4.
4.2 Evaluation of metallic materials
Metallic materials commonly used for the construction of cryogenic vessels do not normally present any
incompatibility when in contact with oxygen. Annex A lists the metallic materials commonly used for
liquid oxygen.
The cases in which ignition or violent reactions can occur are when very thin materials are used with high
surface to volume ratio, and when high ignition energy is available (e.g. pump failure). Materials thinner
than 0,1 mm shall be tested in accordance with 4.4.3 in conditions as close as possible to the actual
operational conditions. Materials to be used in applications where the ignition energy is potentially high
should be subjected to special consideration.
For cryogenic vessels intended for oxygen service, the test described in 4.4.3 shall be performed with
oxygen. When materials are located in an area where contact with condensed enriched air and the
presence of potential sources of ignition is a risk, the test described in 4.4.3 shall be performed with
cryogenic O /N mixtures containing at least 50 % oxygen.
2 2
NOTE Condensed enriched air can be produced on surfaces with temperatures colder than − 191,3 °C at
1)
1 atm (101,325 Pa).
4.3 Evaluation of non-metallic materials
Example of non-metallic materials include, e.g. plastics, elastomers, lubricants, ceramics, glasses, and
glues. Some of these materials present a high risk of ignition when in contact with oxygen and should be
avoided or carefully selected and used in limited quantities.
Some fully oxidized materials, such as ceramics and glass, present no risk of ignition provided they are
not contaminated.
Any combustible non-metallic materials, used in steady or incidental contact with liquid oxygen, where
the presence of a potential source of ignition is a risk, shall be tested in accordance with 4.4.2 and 4.4.3.
Consideration shall be given to testing materials used in those parts of the system where liquid oxygen
accumulation might incidentally occur.
1) According to Annex C of ISO 80000-4:2006, the use of this unit is deprecated.
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ISO 21010:2014(E)

For cryogenic vessels intended for oxygen service, the test described in 4.4.3 shall be performed with
oxygen. When materials are located in an area where contact with condensed enriched air and the
presence of potential sources of ignition is a risk, the test described in 4.4.3 shall be performed with
cryogenic O /N mixtures containing at least 50 % oxygen.
2 2
NOTE Condensed enriched air can be produced on surfaces with temperature colder than − 191,3 °C at 1 atm
(101,325 Pa).
Any combustible non-metallic materials, used in steady or incidental contact with gaseous oxygen
where the presence of potential sources of ignition is a risk, shall be tested in accordance with 4.4.2.
Consideration shall be given to testing materials used in those parts of the system where gaseous oxygen
accumulation might incidentally occur.
4.4 Test methods and acceptance criteria
4.4.1 General
Each material to be tested shall be clearly identified, usually by the commercial name and the
manufacturer’s name.
4.4.2 Ignition tests
4.4.2.1 Pass criteria
Two alternative test methods are described in 4.4.2.2 and 4.4.2.3. Materials not satisfying the
requirements of 4.4.2.2 or 4.4.2.3 can still be used providing they successfully pass, in their actual
operating configuration, the “oxygen pressure surge test” described in 5.3.8 of ISO 10297:2006 (e.g. for
a valve sealing material, the entire valve or a representative assembly shall be tested).
4.4.2.2 Spontaneous ignition test (bomb test)
4.4.2.2.1 Test procedure
The test procedure is given in Annex B.
4.4.2.2.2 Acceptance criteria
The spontaneous ignition temperature determined in accordance with 4.4.2.2.1 shall be no less than the
values given in Table 1.
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