ISO 21010:2017

INTERNATIONAL ISO
STANDARD 21010
Third edition
2017-12
Cryogenic vessels — Gas/material
compatibility
Récipients cryogéniques — Compatibilité gaz/matériaux
Reference number
©
ISO 2017
© ISO 2017, Published in Switzerland
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ii © ISO 2017 – All rights reserved

Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Compatibility of materials with gases other than oxygen . 1
5 General requirements for oxygen service . 1
5.1 Evaluation of materials for oxygen service . 1
5.1.1 General. 1
5.1.2 Evaluation of the insulation system . 2
5.2 Evaluation of metallic materials . 2
5.3 Evaluation of non-metallic materials . 2
5.4 Test methods and acceptance criteria . 3
5.4.1 General. 3
5.4.2 Ignition tests . 3
5.4.3 Insulation test . 4
5.5 Alternative method for 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
Foreword
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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
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URL: www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 220, Cryogenic vessels.
This third edition cancels and replaces the second edition (ISO 21010:2014), which has been technically
revised.
iv © ISO 2017 – All rights reserved

INTERNATIONAL STANDARD ISO 21010:2017(E)
Cryogenic vessels — Gas/material compatibility
1 Scope
This document specifies gas/material compatibility requirements (such as chemical resistance) for
cryogenic vessels, but it does not cover mechanical properties (e.g. for low-temperature applications).
This document provides general guidance for compatibility with gases and detailed compatibility
requirements for oxygen and oxygen-enriched atmospheres. This document 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 document focuses on materials that are normally with or could be in contact with cryogenic fluids.
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 10297:2014, Gas cylinders — Cylinder valves — Specification and type testing
ISO 23208, Cryogenic vessels — Cleanliness for cryogenic service
3 Terms and definitions
No terms and definitions are listed in this document.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at https://www.electropedia.org/
— ISO Online browsing platform: available at https://www.iso.org/obp
4 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 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.
5 General requirements for oxygen service
5.1 Evaluation of materials for oxygen service
5.1.1 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.
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 document 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.
5.1.2 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 5.4.3.
5.2 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 5.4.3.1 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 5.4.3.1 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 5.4.3.1 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 atm (101,325 Pa). The use of atm is deprecated according to ISO 80000-4:2006, Annex C.
5.3 Evaluation of non-metallic materials
Example of non-metallic materials includes 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.
2 © ISO 2017 – All rights reserved

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 5.4.2 and
5.4.3.1. Consideration shall be given to testing materials used in those parts of the system where liquid
oxygen accumulation might incidentally occur.
For cryogenic vessels intended for oxygen service, the test described in 5.4.3 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 5.4.3 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). The use of atm is deprecated according to ISO 80000-4:2006, Annex C.
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 5.4.2.
Consideration shall be given to testing materials used in those parts of the system where gaseous
oxygen accumulation might incidentally occur.
5.4 Test methods and acceptance criteria
5.4.1 General
Each material to be tested shall be clearly identified, usually by the commercial name and the
manufacturer's name.
5.4.2 Ignition tests
5.4.2.1 Pass criteria
Two alternative test methods are described in 5.4.2.2 and 5.4.2.3. Materials not satisfying the
requirements of 5.4.2.2 or 5.4.2.3 can still be used providing they successfully pass, in their actual
operating configuration, the “oxygen pressure surge test” described in ISO 10297:2014, 5.9 (e.g. for a
valve-sealing material, the entire valve or a representative assembly shall be tested).
5.4.2.2 Spontaneous ignition test (bomb test)
5.4.2.2.1 Test pr
...