EN ISO 11114-2:2021

SLOVENSKI STANDARD
01-januar-2022
Nadomešča:
SIST EN ISO 11114-2:2013
Plinske jeklenke - Združljivost materialov za ventil in jeklenko s plinom - 2. del:
Nekovinski materiali (ISO 11114-2:2021)
Gas cylinders - Compatibility of cylinder and valve materials with gas contents - Part 2:
Non-metallic materials (ISO 11114-2:2021)
Gasflaschen - Verträglichkeit von Werkstoffen für Gasflaschen und Ventile mit den in
Berührung kommenden Gasen - Teil 2: Nichtmetallische Werkstoffe (ISO 11114-2:2021)
Bouteilles à gaz - Compatibilité des matériaux des bouteilles et des robinets avec les
contenus gazeux - Partie 2: Matériaux non métalliques (ISO 11114-2:2021)
Ta slovenski standard je istoveten z: EN ISO 11114-2:2021
ICS:
23.020.35 Plinske jeklenke Gas cylinders
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 11114-2
EUROPEAN STANDARD
NORME EUROPÉENNE
November 2021
EUROPÄISCHE NORM
ICS 23.020.35 Supersedes EN ISO 11114-2:2013
English Version
Gas cylinders - Compatibility of cylinder and valve
materials with gas contents - Part 2: Non-metallic
materials (ISO 11114-2:2021)
Bouteilles à gaz - Compatibilité des matériaux des Gasflaschen - Verträglichkeit von Werkstoffen für
bouteilles et des robinets avec les contenus gazeux - Gasflaschen und Ventile mit den in Berührung
Partie 2: Matériaux non métalliques (ISO 11114- kommenden Gasen - Teil 2: Nichtmetallische
2:2021) Werkstoffe (ISO 11114-2:2021)
This European Standard was approved by CEN on 24 October 2021.

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
© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 11114-2:2021 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 11114-2:2021) has been prepared by Technical Committee ISO/TC 58 "Gas
cylinders" in collaboration with Technical Committee CEN/TC 23 “Transportable gas cylinders” the
secretariat of which is held by BSI.
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 May 2022, and conflicting national standards shall be
withdrawn at the latest by May 2022.
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 11114-2:2013.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. A complete listing of these bodies can be found on the CEN website.
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 11114-2:2021 has been approved by CEN as EN ISO 11114-2:2021 without any
modification.
INTERNATIONAL ISO
STANDARD 11114-2
Third edition
2021-10
Gas cylinders — Compatibility of
cylinder and valve materials with gas
contents —
Part 2:
Non-metallic materials
Bouteilles à gaz — Compatibilité des matériaux des bouteilles et des
robinets avec les contenus gazeux —
Partie 2: Matériaux non métalliques
Reference number
ISO 11114-2:2021(E)
ISO 11114-2:2021(E)
© ISO 2021
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 11114-2:2021(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Materials . 2
4.1 General . 2
4.2 Type of materials . 2
5 General consideration .3
6 Specific considerations . 4
6.1 General . 4
6.2 Non-compatibility risks . 4
6.2.1 Violent reaction (oxidation/burning) (F) . 4
6.2.2 Mass loss (W) . 6
6.2.3 Swelling of material (S) . 6
6.2.4 Change in mechanical properties (M) . 6
6.2.5 Other compatibility considerations . 6
7 Compatibility data . .7
7.1 Table of compatibility . 7
7.2 Symbols and abbreviated terms . 8
7.2.1 Symbols for compatibility . 8
7.2.2 Abbreviated terms for materials . 8
7.2.3 Symbols for compatibility risks . 9
7.2.4 Examples . 9
7.2.5 Tables 1 and 2 . 10
Bibliography .20
iii
ISO 11114-2:2021(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.
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).
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. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO’s adherence to
the World Trade 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 58, Gas cylinders, in collaboration with
the European Committee for Standardization (CEN) Technical Committee CEN/TC 23, Transportable gas
cylinders, in accordance with the Agreement on technical cooperation between ISO and CEN (Vienna
Agreement).
This third edition cancels and replaces the second edition (ISO 11114-2:2013), which has been
technically revised. The main changes compared with the previous edition are as follows:
— new materials were added in Table 1;
— Table 2, dedicated to the compatibility for liners, was added.
A list of all parts in the ISO 11114 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
ISO 11114-2:2021(E)
Introduction
This document provides guidance on the compatibility of non-metallic materials used for gas cylinders
and gas cylinder valves with the gas contents of the cylinder. Compatibility of metallic materials is
covered in ISO 11114-1.
Non-metallic materials are very often used for the construction of gas cylinder valves as seals,
e.g. O-ring, gland packing, seats or as lubrication products to avoid friction. They are also commonly
used to ensure sealing of the valve/cylinder connection. For gas cylinders, they are sometimes used as
an internal coating or as a liner for composite materials.
Non-metallic materials not in contact with the gas are not covered by this document.
This document is based on current international experience and knowledge. Some data are derived
from experience involving a mixture of the gas concerned with a dilutant, where no data for single
component gases were available.
[7]
This document has been written so that it is suitable to be referenced in the UN Model Regulations .
v
INTERNATIONAL STANDARD ISO 11114-2:2021(E)
Gas cylinders — Compatibility of cylinder and valve
materials with gas contents —
Part 2:
Non-metallic materials
1 Scope
This document gives guidance on the selection and evaluation of compatibility between non-metallic
materials for gas cylinders and valves and the gas contents. It is also applicable to tubes, pressure
drums and bundles of cylinders.
This document covers composite and laminated materials used for gas cylinders. It does not include
ceramics, glasses and adhesives.
This document considers the influence of the gas in changing the material and mechanical properties
(e.g. chemical reaction or change in physical state). The basic properties of the materials, such as
mechanical properties required for design purposes (normally available from the materials supplier),
are not considered. Other aspects, such as quality of delivered gas, are not considered.
The compatibility data given are related to single component gases but can be applicable to gas
mixtures.
This document does not apply to cryogenic fluids (this is covered in ISO 21010).
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 10286, Gas cylinders — Vocabulary
ISO 10297, Gas cylinders — Cylinder valves — Specification and type testing
ISO 11114-3, Gas cylinders — Compatibility of cylinder and valve materials with gas contents — Part 3:
Autogenous ignition test for non-metallic materials in oxygen atmosphere
ISO 15001, Anaesthetic and respiratory equipment — Compatibility with oxygen
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 10286 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
ISO 11114-2:2021(E)
3.1
competent person
person who has the necessary technical knowledge, qualification, experience and authority to assess
and approve materials for use with gases and to define any special conditions of use that are necessary
[SOURCE: ISO 11114-1:2020, 3.1, modified — “qualification” has been added to the definition.]
3.2
acceptable
satisfactory material/gas combination, under normal conditions of use, provided that any indicated
non-compatibility risks are taken into account
Note 1 to entry: Normal conditions of use are defined in Clause 5.
Note 2 to entry: Non-compatibility risks are provided in Table 1.
3.3
not acceptable
unsafe material/single gas combination, under normal conditions of use
Note 1 to entry: For gas mixtures, special conditions can apply.
Note 2 to entry: Normal conditions of use are defined in Clause 5.
3.4
dynamic sealing
non-metallic material used, in normal operation, to provide a pressure seal between two surfaces that
have relative motion to each other
4 Materials
4.1 General
Non-metallic materials shall be suitable for the intended service. They are suitable if their compatibility
is stated as acceptable in Table 1, and Table 2 for the cylinder liners, or the necessary properties have
been proved by tests or long and safe experience to the satisfaction of a competent person.
NOTE When plastic liner materials are used, it is necessary to use metallic bosses. For compatibility of
metallic bosses, see ISO 11114-1.
If coated materials are used, the suitability of the combination shall be assessed and approved if all
technical aspects have been considered and validated by a competent person. These technical aspects
include, but are not limited to, compatibility of the coating material with the intended gas, durability of
the coating during all its intended use and gas permeability through it.
4.2 Type of materials
The most commonly used non-metallic materials for gas cylinders and cylinder valves can be grouped
as follows:
— plastics;
— elastomers;
— fluid lubricants.
NOTE 1 Solid lubricants are sometimes used, e.g. MoS .
ISO 11114-2:2021(E)
Materials considered in this document are as follows:
a) plastics:
— polytetrafluoroethylene (PTFE);
— polychlorotrifluoroethylene (PCTFE);
— polyvinylidenefluoride (PVDF);
— polyamide (PA);
— polypropylene (PP);
— polyethylene (PE);
NOTE 2 PE covers grades such as HDPE (high density polyethylene), MDPE (medium density
polyethylene), LDPE (low density polyethylene), PEX (cross-linked), etc.
— polyethylene terephthalate (PET);
— polyetheretherketone (PEEK);
— polypropylene sulfide (PPS);
— polyvinyl chloride (PVC);
— polyimide (PI);
— polyoxymethylene (POM);
b) elastomers (rubber):
— butyl rubber (IIR);
— nitrile butadiene rubber (NBR);
— chloroprene rubber (CR);
— fluorocarbon rubber (FKM);
— methyl-vinyl-silicone rubber (VMQ);
— ethylene propylene diene rubber (EPDM);
— polyacrylate rubber (ACM);
— polyurethane rubber (PUR);
— epichlorohydrin rubber (ECO);
— methyl-fluoro-silicone rubber (FVMQ);
c) fluid lubricants:
— hydrocarbon (HC);
— fluorocarbon (FC).
5 General consideration
It is important to note that these materials are generic types. Within each material type there are
variations in the properties of the materials due to polymer differences and formulations used by
manufacturers to modify physical and chemical properties of the material. The user of the material
ISO 11114-2:2021(E)
should therefore consult the manufacturer and, if necessary, carry out tests before using the material
(e.g. for critical services such as oxygen and other oxidizing gases).
Lubricants are often used in valves to reduce friction and wear in the moving parts. For valves used for
oxidizing gases or for gases supporting combustion, if lubrication is required, it shall be ensured that
the lubricant is compatible for the intended application when the lubricated components are in contact
with the oxidizing gas or the gas supporting combustion.
Where the lubricant is listed as “not acceptable” in Table 1 for reasons other than violent reaction
(oxidation/burning) (F), it may be used safely and usually satisfactorily in applications which do not
involve contact in normal operation with the gas. An example of such an application is the lubrication of
the valve actuating mechanism not in contact with the gas.
Where the lubricant is listed as “not acceptable” for the reason of violent reaction (oxidation/burning)
(F), it should not be used in any part of the system that can be contacted by the gas, even under abnormal
conditions such as in the event of a failure of the gas sealing system. If there is a risk of violent reaction,
appropriate safety and suitability tests shall be carried out for the lubricant application before it is used
either on the lubricant itself, as specified in ISO 11114-3, or on the lubricated equipment in which it is
intended to be used, as specified in ISO 10297.
The properties of plastics and elastomers including compatibility are dependent on temperature. Low
temperature can cause hardening and the possibility of embrittlement, whereas high temperature
can cause softening and the possibility of material flow. Users of such materials shall check to ensure
their suitability over the entire operating temperature range specified by the cylinder and valve
manufacturing standards.
Some materials become brittle at low temperatures, especially at temperatures at the lower end of
the normal operating range (e.g. fluorocarbon rubber). Temperatures in the refrigerant or cryogenic
ranges affect many materials and caution shall be exercised at temperatures below −50 ° C. This risk
shall be considered in particular when transfilling by thermal siphoning at low temperature or similar
procedures, or for cylinders regularly filled at low temperatures (e.g. carbon dioxide).
6 Specific considerations
6.1 General
The compatibility of gases with non-metallic materials is affected by chemical reactions and physical
influences, which can be classified as defined in 6.2.
6.2 Non-compatibility risks
6.2.1 Violent reaction (oxidation/burning) (F)
6.2.1.1 Principle
Historically the majority of serious accidents from rapid oxidation or violent combustion have occurred
with oxidizing gas supporting combustion at high pressure. Thorough investigation of all materials and
factors should be conducted with great care and all data should be considered before designing or using
equipment to handle oxidizing gases or gases supporting combustion.
Compatibility depends mainly on the operating conditions (pressure, temperature, gas velocity,
particles, equipment design and application). The risk shall particularly be considered with gases such
as oxygen, fluorine, chlorine and nitrogen trifluoride. Most of the non-metallic materials can be ignited
relatively easily when in contact with oxidizing gases (see ISO 10156) and even when in contact with
gases not classified as oxidizing but still supporting combustion.
The selection of a material for use with oxygen or an oxygen enriched atmosphere, or both, is primarily
a matter of understanding the circumstances that cause the material to react with oxygen. Most
ISO 11114-2:2021(E)
materials in contact with oxygen will not ignite without a source of ignition energy (friction, heat of
compression, particle impacts, etc.). 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 general factors shall be considered:
a) the materials compatibility properties (ease of ignition and energy of combustion);
b) the different energy sources that will produce a sufficient increase in the temperature of the
material.
These general factors should be viewed in the context of the entire system design so that the following
specific factors will assume the proper relative significance:
— the properties of the materials, which include the factors affecting ease of ignition and the conditions
affecting potential resulting damage (heat of reaction);
— the operating conditions [e.g. pressure, temperature, oxygen or oxidizing gas concentrations in a
gas mixture, or both, influence of dilutant (e.g. helium), surface contamination];
— the potential sources of ignition (e.g. friction, heat of compression, heat from mass impact, heat from
particle impact, static electricity, electrical arc, resonance, internal flexing);
— the possible consequence (e.g. effects on the surroundings such as propagation of fire);
— the additional factors (e.g. performance requirements, prior experience, availability).
In conclusion, the evaluation of compatibility of non-metallic materials is more critical than that of
metallic materials, which generally perform well when in contact with oxygen.
6.2.1.2 Specifications for oxidizing gases
In accordance with 6.2.1.1, it is not possible to make a simple statement concerning the compatibility
of non-metallic materials with oxidizing gases such as oxygen, chlorine, nitric oxide, nitrous oxide,
nitrogen dioxide, nitrogen trifluoride, etc. (see ISO 10156).
For fluorine, which is the most oxidizing gas, all non-metallic materials would historically fall into the
classification “not acceptable”.
For fluorine mixtures, the gases industry now has evidence of successful testing and safe history of use
of PTFE and PCTFE under controlled conditions (e.g. low concentration and low pressure). Therefore,
following an assessment and authorization by a competent person, these materials are acceptable in
similar conditions.
Oxygen and other oxidizing gases can react violently when tested with all non-metallic materials listed
in 4.2 a), 4.2 b) and 4.2 c). Some materials such as PTFE and FKM are more resistant to ignition than
other plastics and elastomers. HC lubricants are normally not acceptable. Under certain conditions
other plastics and elastomers listed can be safely used in oxidizing service without presenting some
of the disadvantages of PTFE, i.e. poor mechanical properties and risk of release of toxic products for
breathing gas applications (see ISO 15001), or FKM, i.e. swelling, poor mechanical properties at low
temperature, risk of release of toxic products in breathing gas applications, etc.
Consequently, non-metallic materials may only be used if it has been proven by tests (or long and safe
service experience), taking into account all the operating conditions and especially the design of the
equipment, that their use is safe. ISO 11114-3 and ISO 21010 give test methods for polymeric materials
and fluid lubricants that result in conservative value. Some non-metallic materials can be safely used
at higher pressure if they are satisfactorily tested in the final design configuration, e.g. in ga
...