ISO 21010:2004

INTERNATIONAL ISO
STANDARD 21010
First edition
2004-04-01

Cryogenic vessels — Gas/materials
compatibility
Récipients cryogéniques — Compatibilité gaz/matériaux




Reference number
ISO 21010:2004(E)
©
ISO 2004

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ISO 21010:2004(E)
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ISO 21010:2004(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 . 3
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 21010:2004(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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
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.
ISO 21010 was prepared by Technical Committee ISO/TC 220, Cryogenic vessels.
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INTERNATIONAL STANDARD ISO 21010:2004(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 referenced documents are indispensable for the application 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 10297:1999, Gas cylinders — Refillable gas 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 may 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:
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ISO 21010:2004(E)
 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 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
2 2
mixtures containing at least 50 % oxygen.
1)
NOTE Condensed enriched air can be produced on surfaces with temperatures colder than − 191,3 °C at 1 atm
(= 101,325 Pa).

1) According to Annex C of ISO 31-3:1992, the use of this unit is deprecated.
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ISO 21010:2004(E)
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 may incidentally occur.
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
2 2
mixtures containing at least 50 % oxygen.
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 may
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
4.4.2.1 or 4.4.2.2 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 10297:1999 (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 A.
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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ISO 21010:2004(E)
Table 1 — Minimum spontaneous ignition temperature
Maximum permissible Minimum spontaneous
pressure ignition temperature (SIT) Remark
bar °C
3 200
10 230
20 250
40 300
100 350
150 375
Compleme
...