Gas cylinders - Compatibility of cylinder and valve materials with gas contents - Part 1: Metallic materials (ISO 11114-1:2020)

This document provides requirements for the selection of safe combinations of metallic cylinder and
valve materials and cylinder gas content.
The compatibility data given is related to single gases and to gas mixtures.
Seamless metallic, welded metallic and composite gas cylinders and their valves, used to contain
compressed, liquefied and dissolved gases are considered.
NOTE In this document the term “cylinder” refers to transportable pressure receptacles, which also include
tubes and pressure drums.
Aspects such as the quality of delivered gas product are not considered.

Gasflaschen - Verträglichkeit von Werkstoffen für Gasflaschen und Ventile mit den in Berührung kommenden Gasen - Teil 1: Metallische Werkstoffe (ISO 11114-1:2020)

Dieses Dokument enthält Anforderungen für die Auswahl von sicheren Kombinationen von metallischen Gasflaschen- und Ventilwerkstoffen und den in Berührung kommenden Gasen.
Die Angaben zur Verträglichkeit beziehen sich auf Einzelgase und Gasgemische.
Es sind nahtlose metallische Gasflaschen, geschweißte metallische Gasflaschen und Gasflaschen aus Verbundwerkstoffen (Composite-Gasflaschen) einschließlich ihrer Ventile zur Verwendung mit verdichteten, verflüssigten und gelösten Gasen berücksichtigt.
ANMERKUNG In diesem Dokument wird der Begriff „Flasche“ für ortsbewegliche Druckgefäße, welche auch Großflaschen und Druckfässer umfassen, verwendet.
Aspekte wie die Qualität des gelieferten Gasproduktes werden nicht berücksichtigt.

Bouteilles à gaz - Compatibilité des matériaux des bouteilles et des robinets avec les contenus gazeux - Partie 1: Matériaux métalliques (ISO 11114-1:2020)

Le présent document fournit les exigences pour le choix des combinaisons de matériaux sûres pour les bouteilles à gaz métalliques et leur robinet et les gaz contenus dans la bouteille.
Les données de compatibilité indiquées se rapportent aux gaz à l'état pur et aux mélanges de gaz.
Le présent document prend en considération les bouteilles à gaz métalliques sans soudure, soudées et composites, et leurs robinets utilisés pour contenir des gaz comprimés, liquéfiés et dissous.
NOTE Dans le présent document, le terme «bouteille» se réfère aux récipients à pression transportables qui incluent aussi les tubes et les fûts à pression.
Il ne traite pas d'autres aspects tels que la qualité du produit gazeux fourni.

Plinske jeklenke - Združljivost materialov za ventil in jeklenko s plinom - 1. del: Kovinski materiali (ISO 11114-1:2020)

General Information

Status
Published
Public Enquiry End Date
03-Jul-2019
Publication Date
26-Jul-2020
Technical Committee
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
18-Jun-2020
Due Date
23-Aug-2020
Completion Date
27-Jul-2020

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SLOVENSKI STANDARD
SIST EN ISO 11114-1:2020
01-september-2020
Nadomešča:
SIST EN ISO 11114-1:2012
SIST EN ISO 11114-1:2012/A1:2017

Plinske jeklenke - Združljivost materialov za ventil in jeklenko s plinom - 1. del:

Kovinski materiali (ISO 11114-1:2020)

Gas cylinders - Compatibility of cylinder and valve materials with gas contents - Part 1:

Metallic materials (ISO 11114-1:2020)

Gasflaschen - Verträglichkeit von Werkstoffen für Gasflaschen und Ventile mit den in

Berührung kommenden Gasen - Teil 1: Metallische Werkstoffe (ISO 11114-1:2020)

Bouteilles à gaz - Compatibilité des matériaux des bouteilles et des robinets avec les

contenus gazeux - Partie 1: Matériaux métalliques (ISO 11114-1:2020)
Ta slovenski standard je istoveten z: EN ISO 11114-1:2020
ICS:
23.020.35 Plinske jeklenke Gas cylinders
23.060.40 Tlačni regulatorji Pressure regulators
SIST EN ISO 11114-1:2020 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN ISO 11114-1:2020
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SIST EN ISO 11114-1:2020
EN ISO 11114-1
EUROPEAN STANDARD
NORME EUROPÉENNE
June 2020
EUROPÄISCHE NORM
ICS 23.020.35 Supersedes EN ISO 11114-1:2012
English Version
Gas cylinders - Compatibility of cylinder and valve
materials with gas contents - Part 1: Metallic materials
(ISO 11114-1:2020)

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 1: Matériaux métalliques (ISO 11114-1:2020) kommenden Gasen - Teil 1: Metallische Werkstoffe

(ISO 11114-1:2020)
This European Standard was approved by CEN on 11 May 2020.

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

© 2020 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 11114-1:2020 E

worldwide for CEN national Members.
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SIST EN ISO 11114-1:2020
EN ISO 11114-1:2020 (E)
Contents Page

European foreword ....................................................................................................................................................... 3

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SIST EN ISO 11114-1:2020
EN ISO 11114-1:2020 (E)
European foreword

This document (EN ISO 11114-1:2020) 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 December 2020, and conflicting national standards

shall be withdrawn at the latest by December 2020.

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 11114-1:2012.

This document has been prepared under a mandate given to CEN by the European Commission and the

European Free Trade Association.

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 11114-1:2020 has been approved by CEN as EN ISO 11114-1:2020 without any

modification.
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SIST EN ISO 11114-1:2020
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SIST EN ISO 11114-1:2020
INTERNATIONAL ISO
STANDARD 11114-1
Third edition
2020-05
Gas cylinders — Compatibility of
cylinder and valve materials with gas
contents —
Part 1:
Metallic materials
Bouteilles à gaz — Compatibilité des matériaux des bouteilles et des
robinets avec les contenus gazeux —
Partie 1: Matériaux métalliques
Reference number
ISO 11114-1:2020(E)
ISO 2020
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SIST EN ISO 11114-1:2020
ISO 11114-1:2020(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2020

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
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved
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SIST EN ISO 11114-1:2020
ISO 11114-1:2020(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 Cylinder materials ................................................................................................................................................................................ 2

4.3 Valve materials ........................................................................................................................................................................................ 3

4.3.1 General...................................................................................................................................................................................... 3

4.3.2 Particular considerations ......................................................................................................................................... 3

5 Compatibility criteria ...................................................................................................................................................................................... 3

5.1 General ........................................................................................................................................................................................................... 3

5.2 Corrosion ..................................................................................................................................................................................................... 4

5.2.1 General...................................................................................................................................................................................... 4

5.2.2 Corrosion in dry conditions ................................................................................................................................... 4

5.2.3 Corrosion in wet conditions ................................................................................................................................... 4

5.2.4 Corrosion by impurities ............................................................................................................................................. 4

5.3 Hydrogen embrittlement phenomenon ............................................................................................................................ 5

5.4 Generation of dangerous products ........................................................................................................................................ 5

5.5 Violent reactions (e.g. ignition) ................................................................................................................................................ 5

5.6 Stress corrosion cracking ............................................................................................................................................................... 5

6 Material compatibility .................................................................................................................................................................................... 5

6.1 Table of compatibility for single gases ............................................................................................................................... 5

6.2 Compatibility for gas mixtures .................................................................................................................................................. 5

6.3 Using Table 1 ............................................................................................................................................................................................. 6

6.3.1 Conventions and numbers ....................................................................................................................................... 6

6.3.2 Abbreviations for materials.................................................................................................................................... 6

Annex A (informative) Gas/materials NQSAB compatibility code ......................................................................................37

Bibliography .............................................................................................................................................................................................................................48

© ISO 2020 – All rights reserved iii
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SIST EN ISO 11114-1:2020
ISO 11114-1:2020(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 11114-1:2012), which has been

technically revised. It also incorporates the Amendment ISO 11114-1:2012/Amd.1:2017. The main

changes compared to the previous edition are as follows:
— inclusion of all changes in ISO 11114-1:2012/Amd.1:2017;
— clarification of the definition of dry;
— addition of notes in Table 1.
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 2020 – All rights reserved
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SIST EN ISO 11114-1:2020
ISO 11114-1:2020(E)
Introduction

Industrial, medical and special gases (e.g. high-purity gases, calibration gases) can be transported or

stored in gas cylinders. An essential requirement of the material from which such gas cylinders and

their valves are manufactured is compatibility with the gas content.

Compatibility of cylinder materials with gas content has been established over many years by practical

application and experience. Existing national and international regulations and standards do not fully

cover this aspect.
This document is based on current international experience and knowledge.
[1]

This document has been written so that it is suitable to be referenced in the UN Model Regulations .

© ISO 2020 – All rights reserved v
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SIST EN ISO 11114-1:2020
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SIST EN ISO 11114-1:2020
INTERNATIONAL STANDARD ISO 11114-1:2020(E)
Gas cylinders — Compatibility of cylinder and valve
materials with gas contents —
Part 1:
Metallic materials
1 Scope

This document provides requirements for the selection of safe combinations of metallic cylinder and

valve materials and cylinder gas content.
The compatibility data given is related to single gases and to gas mixtures.

Seamless metallic, welded metallic and composite gas cylinders and their valves, used to contain

compressed, liquefied and dissolved gases are considered.

NOTE In this document the term “cylinder” refers to transportable pressure receptacles, which also include

tubes and pressure drums.
Aspects such as the quality of delivered gas product are not considered.
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 10156, Gas cylinders — Gases and gas mixtures — Determination of fire potential and oxidizing ability

for the selection of cylinder valve outlets
ISO 10286, Gas cylinders — Terminology
ISO 10297, Gas cylinders — Cylinder valves — Specification and type testing

ISO 11114-2, Gas cylinders — Compatibility of cylinder and valve materials with gas contents — Part 2:

Non-metallic materials

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
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/
3.1
competent person

person who has the necessary technical knowledge, experience and authority to assess and approve

materials for use with gases and to define any special conditions of use that are necessary

© ISO 2020 – All rights reserved 1
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SIST EN ISO 11114-1:2020
ISO 11114-1:2020(E)
3.2
acceptable

material/gas combination that is safe under normal conditions of use, provided that any indicated

non-compatibility risks are taken into account

Note 1 to entry: Low levels of impurities can affect the acceptability of some single gases or gas mixtures.

3.3
not acceptable

material/single gas combination that is not safe under all normal conditions of use

Note 1 to entry: For gas mixtures special conditions may apply (see 6.2 and Table 1).

3.4
dry

state in which there is no free water in a cylinder under any service conditions, including at the highest

expected operating pressure and at the lowest expected operating temperature

Note 1 to entry: For compressed gases at, for example, 200 bar and −20 °C, the maximum moisture content is

not to exceed 5 ppmV, to avoid condensation of free water. For other temperatures and pressures, the maximum

moisture content needed to avoid condensation of water will be different. Another source of moisture to be

considered is the cylinder itself which implies appropriate drying procedures such as purging and vacuuming.

3.5
wet
state in which the conditions as defined for dry (3.4) are not met
3.6
gas mixture

combination of different single gases deliberately mixed in specified proportions

3.7
single gas
gas which does not contain deliberately added content of another gas or gases
4 Materials
4.1 General

The compatibility of most materials used to manufacture gas cylinders and valves is identified in this

document.

Other materials whose compatibility is not identified in this document may be used if all compatibility

aspects have been considered and validated by a competent person.
4.2 Cylinder materials

The most commonly used metallic materials for cylinders are (among others) carbon manganese steel,

chromium molybdenum steel, chromium molybdenum nickel steel, stainless steel and aluminium

alloys, as specified in the following documents:
— aluminium and aluminium alloys: ISO 6361-2, ISO 7866 and ISO 11118;

— steel: ISO 4706, ISO 9328-5, ISO 9809-1, ISO 9809-2, ISO 9809-3, ISO 11118 and ISO 11120;

— stainless steel: ISO 9809-4 and ISO 15510.
2 © ISO 2020 – All rights reserved
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SIST EN ISO 11114-1:2020
ISO 11114-1:2020(E)
4.3 Valve materials
4.3.1 General

The most commonly used metallic materials for valve bodies and internal gas wetted parts are brass

and other similar copper-based alloys, carbon steel, stainless steel, refined nickel and nickel alloys, Cu–

Be (2 %) and aluminium alloys.
4.3.2 Particular considerations

4.3.2.1 In special cases, non-compatible materials may be used for non-oxidizing gases if suitably

plated, protected or coated. This may only be done if all compatibility aspects have been considered and

validated by a competent person for the entire life of the valve.

4.3.2.2 Special precautions, in accordance with ISO 11114-3 (which addresses testing, not precautions

per se), shall be taken for oxidizing gases as specified in ISO 10156. In this case, non-compatible materials

are not acceptable (see 3.3) for use in valves, even if plated, protected or coated.

4.3.2.3 For cylinder valves, compatibility in wet conditions shall be considered because of the high risk

of contamination by atmospheric moisture and an airborne contaminant.

NOTE Reference is made in this document to stainless steels by their commonly used AISI identification

numbers, i.e. 304. For example, the equivalent grades according to EN 10088-1 are as follows:

304 1.4301
304L 1.4306 and 1.4307
316 1.4401
316L 1.4404
316Ti 1.4571
321 1.4541
904L 1.4539
5 Compatibility criteria
5.1 General

Compatibility between a gas and the cylinder/valve material is affected by chemical reactions and

physical influences, which can be classified into five categories:
— corrosion;
— stress corrosion cracking;
— hydrogen embrittlement;
— generation of dangerous products through chemical reaction;
— violent reactions, such as ignition.

Non-metallic components (valve sealing, gland packing, O-ring, etc.) shall be in accordance

with ISO 11114-2.

Sealing or lubricating materials (when used) at the valve stem shall be compatible with the gas content.

NOTE Annex A gives the gas/materials NQSAB compatibility codes, for information.
© ISO 2020 – All rights reserved 3
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SIST EN ISO 11114-1:2020
ISO 11114-1:2020(E)
5.2 Corrosion
5.2.1 General

Many types of corrosion mechanisms can occur due to the presence of the gas, as outlined in 5.2.2 to 5.2.4.

5.2.2 Corrosion in dry conditions

This corrosion is affected by chemical attack by a dry gas on the cylinder material. The result is a

reduction of the cylinder wall thickness. This type of corrosion is not very common, because the rate of

dry corrosion is very low at ambient temperature.
5.2.3 Corrosion in wet conditions

This is the most common type of corrosion, which only occurs in a gas cylinder due to the presence of

free water or aqueous solutions. However, with some hygroscopic gases (e.g. HCl, Cl ) corrosion would

occur even if the water content were less than the saturation value. Therefore, some gas/material

combinations are not recommended, even if inert in the theoretical dry conditions. It is thus very

important to prevent any water ingress into gas cylinders. The most common sources of or reasons for

water ingress are:

a) the customer, by retro-diffusion/backfilling or when the cylinder is empty, by air entry, if the valve

is not closed,
b) ineffective drying following hydraulic testing, and
c) during filling.

In some cases, it is very difficult to completely prevent water ingress – particularly when the gas is

hygroscopic (e.g. HCl, Cl ). In cases where the filler cannot guarantee the dryness of gas and cylinder, a

cylinder material which is compatible with the wet gas shall be used, even if the dry gas is not corrosive.

There are several different types of “wet corrosion” in alloys:

1) general corrosion leading to the reduction of the wall thickness, e.g. by acid gases (CO , SO ) or

2 2
oxidizing gases (O , Cl );
2 2
2) localized corrosion, e.g. pitting corrosion or grain boundary attack.

Additionally, some gases, even inert ones, when hydrolysed could lead to the production of corrosive

products.
5.2.4 Corrosion by impurities

Gases which themselves are inert (non-corrosive) can cause corrosion due to the presence of impurities.

Contamination of gases can occur, during filling, during use or if the initial product is not properly

purified.
The most common pollutants are:

a) atmospheric air, in which case the harmful impurities can be moisture (see also 5.2.3) and oxygen

(e.g. in liquefied ammonia);
b) aggressive products contained in some gases, e.g. H S in natural gas;

c) aggressive traces (acid, mercury, etc.) remaining from the manufacturing process of some gases.

The materials compatible with the impurities shall be used if the presence of these impurities cannot be

prevented and if the corresponding corrosion rate is unacceptable for the intended application.

4 © ISO 2020 – All rights reserved
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SIST EN ISO 11114-1:2020
ISO 11114-1:2020(E)
5.3 Hydrogen embrittlement phenomenon

Embrittlement caused by hydrogen can occur at ambient temperature in the case of certain gases and

under service conditions which stress the cylinder or valve material.

This type of stress cracking phenomenon can, under certain conditions, lead to the failure of gas

cylinders and/or valve components containing hydrogen, mixtures of hydrogen and other gases.

5.4 Generation of dangerous products

In some cases, reactions of a gas with a metallic material can lead to the generation of dangerous

products. Examples are the possible reactions of C H with copper alloys containing more than 65 %

2 2
copper and of CH Cl in aluminium alloy cylinders.
5.5 Violent reactions (e.g. ignition)

In principle, violent reactions of gas/metallic material are not very common at ambient temperatures,

because high activation energies are necessary to initiate such reactions. In the case where a

combination of non-metallic and metallic materials is used, e.g. for valves, this type of reaction can

occur with some gases (e.g. O , Cl ).
2 2
5.6 Stress corrosion cracking

Stress corrosion cracking can occur in many metallic materials subjected to stress, moisture and

a contaminant at the same time. Stress corrosion cracking can, under certain conditions, lead to the

failure of the gas cylinder or valve and/or its components (e.g. ammonia in contact with copper alloy

valves or carbon monoxide/carbon dioxide mixtures in steel cylinders).
6 Material compatibility
6.1 Table of compatibility for single gases

Before any gas/cylinder/valve combination is chosen a careful study of all the key compatibility

characteristics given in Table 1 shall be made. Particular attention shall be paid to any restrictions,

which shall be applied to acceptable materials.
NOTE The gases are generally listed in the table in English alphabetical order.
6.2 Compatibility for gas mixtures

Any gas mixtures containing single gases that are all compatible with a given material shall be

considered as being compatible with this material.

For gas mixtures containing gases causing embrittlement (see 5.3, and Clause A.4, groups 2 and 11) the risk

of hydrogen embrittlement only occurs if the partial pressure of the gas is greater than 5 MPa (50 bar) and

the stress level of the cylinder material is high enough. In a gas mixture, the partial pressure for hydrogen

sulphide and methyl mercaptan shall be less than 0,25 MPa (2,5 bar) at a maximum UTS (ultimate tensile

strength) of 950 MPa. If the stress level of the cylinder material is high, see Table 1, row 63.

Some International Standards, such as ISO 11114-4, specify test methods for selecting appropriate

steels with a maximum UTS greater than 950 MPa.

For the halogenated gases that are not compatible with aluminium alloy cylinders, the maximum

acceptable concentration in gas mixtures shall be limited to 0,1 % as indicated in Table 1 unless higher

concentrations have been validated after conducting specific tests (examples of such tests are given

[14]

in EIGA document 161/16 ). The moisture content (dryness) in these mixtures shall be limited to a

maximum of 10 ppmV.
© ISO 2020 – All rights reserved 5
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SIST EN ISO 11114-1:2020
ISO 11114-1:2020(E)

For non-compatibility of some halogenated gases with aluminium alloys, the maximum acceptable

content is given in Table 1. The level of moisture can affect the acceptability of such mixtures.

6.3 Using Table 1
6.3.1 Conventions and numbers

In Table 1, bold face type indicates that the material is commonly used under normal service conditions:

— A = acceptable (see 3.2);
— N = not acceptable (see 3.3).
If there is no UN number listed for a gas (or liquid), the gas has no
...

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