EN ISO 11118:2015

Gas cylinders - Non-refillable metallic gas cylinders - Specification and test methods (ISO 11118:2015)

ISO 11118:2015 specifies minimum requirements for the material, design, inspections, construction and workmanship, manufacturing processes, and tests at manufacture of non-refillable metallic gas cylinders of welded, brazed, or seamless construction for compressed and liquefied gases including the requirements for their non-refillable sealing devices and their methods of testing.
NOTE          The specific gases permitted in cylinders constructed to this International Standard can be limited by national or international requirements.
This International Standard is applicable to cylinders where
a)    the test pressure does not exceed 250 bar (i.e. ph ≤ 250 bar) for liquefied gases and 450 bar for compressed gases;
b)    the product of the test pressure and the water capacity does not exceed 1 000 bar·litres (i.e. ph V ≤ 1 000 bar L);
c)    the test pressure exceeds 45 bar and the water capacity does not exceed 5 l (i.e. for ph > 45 bar, then V ≤ 5 l).

Gasflaschen - Metallische Einwegflaschen - Spezifikationen und Prüfverfahren (ISO 11118:2015)

Diese Internationale Norm legt Mindestanforderungen an Werkstoff, Auslegung, Inspektionen, Bau und Ausführung, Herstellungsprozesse und Fertigungsprüfungen von geschweißten, hartgelöteten oder nahtlosen metallischen Einwegflaschen für verdichtete und verflüssigte Gase sowie die Anforderungen an deren Einwegdichteinrichtungen und die zugehörigen Prüfverfahren fest.
ANMERKUNG Die spezifischen Gase, welche in nach dieser Internationalen Norm konstruierte Flaschen gefüllt werden dürfen, können durch nationale oder internationale Anforderungen begrenzt sein.
Diese Internationale Norm gilt für Flaschen, bei denen:
a) der Prüfdruck bei verflüssigten Gasen 250 bar (d. h. ph ≤ 250 bar) und bei verdichteten Gasen 450 bar nicht überschreitet;
b) das Produkt aus Prüfdruck und Fassungsraum 1 000 bar∙l (d. h. phV ≤ 1 000 bar∙l) nicht überschreitet;
c) der Prüfdruck 45 bar überschreitet und der Fassungsraum 5 l nicht überschreitet (d. h. bei ph > 45 bar gilt V ≤ 5 l).

Bouteilles à gaz - Bouteilles à gaz métalliques non rechargeables - Spécifications et méthodes d'essai (ISO 11118:2015)

ISO 11118:2015 spécifie les exigences minimales applicables aux matériaux, à la conception, aux contrôles, à la fabrication et à la qualité d'exécution ainsi qu'aux procédés de fabrication et aux essais chez le fabricant de bouteilles à gaz métalliques non rechargeables, soudées, brasées ou sans soudure, utilisées pour les gaz comprimés et liquéfiés, y compris les exigences pour leurs dispositifs d'étanchéité non réutilisables et leur méthode d'essai.
NOTE          Les gaz spécifiques autorisés pour les bouteilles non rechargeables construites en conformité avec la présente Norme internationale peuvent être limités par des exigences nationales ou internationales.
La présente Norme internationale est applicable aux bouteilles non rechargeables dont:
a)    la pression d'épreuve ne dépasse pas 250 bar (c'est-à-dire ph ≤ 250 bar) pour les gaz liquéfiés et 450 bar pour les gaz comprimés;
b)    le produit de la pression d'épreuve par la contenance en eau ne dépasse pas 1 000 bar·litres (soit ph V ≤ 1 000 bar l);
c)    la pression d'épreuve dépasse 45 bar et la contenance en eau ne dépasse pas 5 l (c'est-à-dire que pour ph > 45 bar, alors V ≤ 5 l).

Plinske jeklenke - Kovinske plinske jeklenke za enkratno polnitev - Specifikacija in preskusne metode (ISO 11118:2015)

Standard določa minimalne zahteve za material, konstruiranje, izdelavo in izvedbo, postopke izdelave in preskuse ob času proizvodnje varjenih, trdo spajkanih ali nevarjenih kovinskih plinskih jeklenk za enkratno polnitev za stisnjene, utekočinjene in raztopljene pline, izpostavljene ekstremnim temperaturam po vsem svetu.

General Information

• Status: Withdrawn
• Publication Date: 20-Oct-2015
• Withdrawal Date: 13-Apr-2025
• ICS: 23.020.30 - Pressure vessels, gas cylinders
• ICS: 23.020.35 - Gas cylinders
• Technical Committee: CEN/TC 23 - Transportable gas cylinders
• Drafting Committee: CEN/TC 23/SC 1/WG 5 - Non refillable cylinders
• Current Stage: 9960 - Withdrawal effective - Withdrawal
• Start Date: 22-Jan-2025
• Completion Date: 14-Apr-2025
• Directive: 2008/68/EC - Directve 2008/68/EC of the European Parliament and of the council of 24 September 2008 on the inland transport of the dangerous goods
• Directive: 94/55/EC - Transport of dangerous goods by road
• Directive: 96/49/EC - Transport of dangerous goods by rail
• Mandate: M/086 - Mandate to CEN for standardization in the field of transport of dangerous goods
• Ref Project: SIST EN ISO 11118:2016 - Gas cylinders - Non-refillable metallic gas cylinders - Specification and test methods (ISO 11118:2015)

Relations

• Replaces: EN 12205:2001 - Transportable gas cylinders - Non-refillable metallic gas cylinders
• Effective Date: 16-Dec-2015
• Replaces: EN ISO 13340:2001 - Transportable gas cylinders - Cylinder valves for non-refillable cylinders - Specification and prototype testing (ISO 13340:2001)
• Effective Date: 18-Nov-2015
• Replaced By: EN ISO 11118:2025 - Gas cylinders - Non-refillable metallic gas cylinders - Specification and test methods (ISO 11118:2025)
• Effective Date: 16-Nov-2022
• Amended By: EN ISO 11118:2015/A1:2020 - Gas cylinders - Non-refillable metallic gas cylinders - Specification and test methods - Amendment 1 (ISO 11118:2015/Amd 1:2019)
• Effective Date: 07-Mar-2018
• Amended By: EN ISO 11118:2015/prA1 - Gas cylinders - Non-refillable metallic gas cylinders - Specification and test methods (ISO 11118:2015/DAM 1:2017)
• Effective Date: 14-Dec-2016

Standards Content (Sample)

SLOVENSKI STANDARD
01-februar-2016
1DGRPHãþD
SIST EN 12205:2002
SIST EN ISO 13340:2002
Plinske jeklenke - Kovinske plinske jeklenke za enkratno polnitev - Specifikacija in
preskusne metode (ISO 11118:2015)
Gas cylinders - Non-refillable metallic gas cylinders - Specification and test methods
(ISO 11118:2015)
Gasflaschen - Metallische Einwegflaschen - Spezifikation und Prüfmethoden (ISO
11118:2015)
Bouteilles à gaz - Bouteilles à gaz métalliques non rechargeables - Spécifications et
méthodes d'essai (ISO 11118:2015)
Ta slovenski standard je istoveten z: EN ISO 11118:2015
ICS:
23.020.30 7ODþQHSRVRGHSOLQVNH Pressure vessels, gas
MHNOHQNH cylinders
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 11118
EUROPEAN STANDARD
NORME EUROPÉENNE
October 2015
EUROPÄISCHE NORM
ICS 23.020.30 Supersedes EN ISO 13340:2001
English Version
Gas cylinders - Non-refillable metallic gas cylinders -
Specification and test methods (ISO 11118:2015)
Bouteilles à gaz - Bouteilles à gaz métalliques non Gasflaschen - Metallische Einwegflaschen -
rechargeables - Spécifications et méthodes d'essai (ISO Festlegungen und Prüfverfahren (ISO 11118:2015)
11118:2015)
This European Standard was approved by CEN on 22 August 2015.

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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, 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: Avenue Marnix 17, B-1000 Brussels
© 2015 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 11118:2015 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
European foreword
This document (EN ISO 11118:2015) has been prepared by Technical Committee ISO/TC 58 "Gas
cylinders" in collaboration with the 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 April 2016, and conflicting national standards shall be
withdrawn at the latest by April 2016.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent
rights.
This document supersedes EN ISO 13340:2001.
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, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
Endorsement notice
The text of ISO 11118:2015 has been approved by CEN as EN ISO 11118:2015 without any modification.

INTERNATIONAL ISO
STANDARD 11118
Second edition
2015-09-15
Gas cylinders — Non-refillable
metallic gas cylinders — Specification
and test methods
Bouteilles à gaz — Bouteilles à gaz métalliques non rechargeables —
Spécifications et méthodes d’essai
Reference number
ISO 11118:2015(E)
©
ISO 2015
ISO 11118:2015(E)
© ISO 2015, Published in Switzerland
All rights reserved. Unless otherwise specified, 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
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. [phone]
Fax [phone]
[e-mail]
www.iso.org
ii © ISO 2015 – All rights reserved

ISO 11118:2015(E)
Contents Page
Foreword .v
Introduction .vii
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Symbols . 3
5 Materials . 3
5.1 General requirements . 3
5.2 Material types . 4
5.2.1 Carbon and low-alloy steels . 4
5.2.2 Aluminium and aluminium alloy . 4
5.2.3 Austenitic stainless steels . 4
5.3 Chemical compositions . 5
5.3.1 Carbon and low-alloy steels . 5
5.3.2 Aluminium and aluminium alloys . 5
6 Inspection and testing . 6
7 Design . 6
7.1 General requirements . 6
7.2 Calculation of pressure containing parts . 6
7.3 Design drawings . 7
8 Construction and workmanship . 7
8.1 Construction . 7
8.1.1 Types of construction of cylinder shell . 7
8.1.2 Cylinder non-refillability.11
8.1.3 Pressure relief devices .11
8.2 Workmanship .11
9 Type approval procedure .12
9.1 General requirements .12
9.2 Prototype tests .12
9.2.1 General.12
9.2.2 Material tests . .12
9.2.3 Tensile tests .13
9.2.4 Burst tests .13
9.2.5 Drop tests .15
9.2.6 Dimension checks .16
9.2.7 Valve to cylinder interface test .16
9.3 Design type approval .16
10 Batch tests .17
10.1 General requirements .17
10.2 Failure to meet test requirements .17
11 Tests on every cylinder .17
12 Markings .18
12.1 General .18
12.2 Manufacturing and operational markings .18
12.3 Other markings .19
13 Test reports and certificate of compliance .19
Annex A (normative) Non-refillable sealing devices — Specifications and prototype testing .20
Annex B (informative) Type approval certificate .26
ISO 11118:2015(E)
Annex C (informative) Certificate of compliance .28
Annex D (informative) Yield point elongation (YPE) .30
Bibliography .33
iv © ISO 2015 – All rights reserved

ISO 11118:2015(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 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 58, Gas cylinders, Subcommittee SC 3,
Cylinder design.
This second edition cancels and replaces the first edition (ISO 11118:1999) and ISO 13340:2001, which
have been technically revised with the following changes:
— removed references to dissolved gases from the Scope;
— the edition aligns ISO 11118 and EN 12205;
— incorporates ISO 13340 in ISO 11118;
— incorporated new titles of ISO referenced documents;
— incorporated definitions and use of R , R , R , and R ;
ea eg ma mg
— clarified requirements for the processing of carbon steel to avoid strain aging;
— added pierceable metal membranes to cylinder non-refillability;
— added test requirement for aluminium materials for intercrystalline corrosion for seamless and
welded aluminium cylinders;
— included alternative temperatures for artificial aging of carbon steel cylinder prior to burst testing;
— modified markings to align with UN requirements;
— clarified inspection criteria for each cylinder;
— corrected references to correct Annexes;
— modified burst pressure to align with other ISO Standards;
— aligned test pressure requirement of non-refillable sealing device to the same as the cylinder;
ISO 11118:2015(E)
— modified Annex B for completeness;
— deleted existing Annex C since it was not needed and inserted a new Annex C for accuracy;
— added new informative Annex D for informational purposes on yield point elongation (YPE).
vi © ISO 2015 – All rights reserved

ISO 11118:2015(E)
Introduction
This International Standard addresses the general requirements on design, construction, and initial
inspection and testing of non-refillable metallic gas cylinders and their non-refillable sealing devices of the
United Nations Recommendations on the Transport of Dangerous Goods: Model Regulations. The purpose
of this International Standard is to provide a specification for the design, manufacture, inspection, and
testing of non-refillable metallic gas cylinders for worldwide safe use, handling, and transport.
The objective is to balance design and economic efficiency against international acceptance and
universal utility.
This International Standard aims to eliminate the concern about climate, duplicate inspections, and
restrictions currently existing because of lack of definitive International Standards. This International
Standard does not reflect on the suitability of the practice of any nation or region.
INTERNATIONAL STANDARD ISO 11118:2015(E)
Gas cylinders — Non-refillable metallic gas cylinders —
Specification and test methods
1 Scope
This International Standard specifies minimum requirements for the material, design, inspections,
construction and workmanship, manufacturing processes, and tests at manufacture of non-refillable
metallic gas cylinders of welded, brazed, or seamless construction for compressed and liquefied gases
including the requirements for their non-refillable sealing devices and their methods of testing.
NOTE The specific gases permitted in cylinders constructed to this International Standard can be limited by
national or international requirements.
This International Standard is applicable to cylinders where
a) the test pressure does not exceed 250 bar (i.e. p ≤ 250 bar) for liquefied gases and 450 bar for
h
compressed gases;
b) the product of the test pressure and the water capacity does not exceed 1 000 bar·litres (i.e.
p V ≤ 1 000 bar L);
h
c) the test pressure exceeds 45 bar and the water capacity does not exceed 5 l (i.e. for p > 45 bar,
h
then V ≤ 5 l).
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 3651-2, Determination of resistance to intergranular corrosion of stainless steels — Part 2: Ferritic,
austenitic and ferritic-austenitic (duplex) stainless steels — Corrosion test in media containing sulfuric acid
ISO 4706:2008, Gas cylinders — Refillable welded steel cylinders — Test pressure 60 bar and below
ISO 6892-1, Metallic materials — Tensile testing — Part 1: Method of test at room temperature
ISO 7866:2012, Gas cylinders — Refillable seamless aluminium alloy gas cylinders — Design,
construction and testing
ISO 9329-1, Seamless steel tubes for pressure purposes — Technical delivery conditions — Part 1: Unalloyed
steels with specified room temperature properties
ISO 9606-1, Qualification testing of welders — Fusion welding — Part 1: Steels
ISO 9809-1:2010, Gas cylinders — Refillable seamless steel gas cylinders — Design, construction and
testing — Part 1: Quenched and tempered steel cylinders with tensile strength less than 1 100 MPa
ISO 9809-4:2014, Gas cylinders — Refillable seamless steel gas cylinders — Design, construction and
testing — Part 4: Stainless steel cylinders with an Rm value of less than 1 100 MPa
ISO 10156, Gases and gas mixtures — Determination of fire potential and oxidizing ability for the selection
of cylinder valve outlets
ISO 10297, Gas cylinders — Cylinder valves — Specification and type testing
ISO 11118:2015(E)
ISO 11114-1, Gas cylinders — Compatibility of cylinder and valve materials with gas contents — Part 1:
Metallic materials
ISO 11114-2, Gas cylinders — Compatibility of cylinder and valve materials with gas contents — Part 2:
Non-metallic materials
ISO 15613, Specification and qualification of welding procedures for metallic materials — Qualification
based on pre-production welding test
ISO 15614-1, Specification and qualification of welding procedures for metallic materials — Welding
procedure test — Part 1: Arc and gas welding of steels and arc welding of nickel and nickel alloys
ISO 20703:2006, Gas cylinders — Refillable welded aluminium-alloy cylinders — Design, construction and
testing
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
batch
quantity of completed and pressure tested cylinders made consecutively by the same manufacturer
using the same manufacturing techniques to the same design, size, and material specifications using
the same type of welding machines (when applicable), welding procedures (when applicable), and to the
same heat treatment conditions (when applicable)
Note 1 to entry: See Clause 10 for details.
3.2
cylindrical shell
portion of the cylinder excluding the cylinder ends which is parallel to the centreline axis of the cylinder
3.3
cylinder shell
empty cylinder before affixing the non-refillable sealing device (3.12), but including all other
permanent attachments
3.4
material certificate
document issued by the material manufacturer which certifies the chemical analysis, mechanical
properties, heat treatment, processing techniques, or other properties/features if required
3.5
burst pressure
highest pressure reached in a cylinder during the burst test
3.6
test pressure
required pressure applied during the pressure test
3.7
working pressure
settled pressure of compressed gas at a uniform reference temperature of 15 °C (288 K) in a full gas
cylinder
3.8
minimum operating temperature
minimum ambient temperature to which the cylinder contents can be exposed, but not exceeding −20 °C
Note 1 to entry: See 5.1.6.
2 © ISO 2015 – All rights reserved

ISO 11118:2015(E)
3.9
non-refillable cylinder
cylinder including a non-refillable sealing device (3.12) that permits the cylinder to be filled only once
Note 1 to entry: Where there is no risk of ambiguity, the short abbreviated form “cylinder” is used in this
International Standard.
3.10
water capacity
volume of water required to completely fill an empty cylinder
3.11
processor
facility that anneals, rolls, slits, or otherwise, changes the material from the form received from the
location where the steel was melted
3.12
non-refillable sealing device
device permanently attached to the cylinder which, once activated, prevents the cylinder from
being refilled
4 Symbols
a calculated minimum thickness, in millimetres, of the cylindrical shell
D nominal outside diameter of the cylinder, in millimetres
F design stress factor (variable)
P burst pressure of the cylinder, in bar
b
p test pressure, in bar above atmospheric pressure
h
p working pressure, in bar above atmospheric pressure
w
p non-refillable sealing device test pressure, in bar above atmospheric pressure
vt
R actual value of the yield strength, in megapascals, of the cylinder when tested
ea
R minimum guaranteed value of the yield strength, in megapascals, for the finished cylinder
eg
R actual value of the tensile strength, in megapascals, of the cylinder when tested
ma
R minimum guaranteed value of the tensile strength, in megapascals, for the finished cylinder
mg
V water capacity of the cylinder, in litres
5 Materials
5.1 General requirements
5.1.1 Cylinder shells shall be made of carbon or low alloy steels, austenitic stainless steel, aluminium,
or aluminium alloys. The materials used shall be specified by type (see 5.2) and chemical composition
(see 5.3). Materials shall not contain seams, cracks, laminations, or other injurious defects. For material
requirements of non-refillable sealing devices, see Annex A.
5.1.2 The cylinder manufacturer shall specify the chemical and mechanical requirements to the
material supplier.
ISO 11118:2015(E)
5.1.3 The cylinder manufacturer shall obtain a material certificate from the manufacturer/processor
of the material certifying the chemical analysis of the cast. The certificate shall be issued by the
manufacturer of the material and shall confirm compliance to the material specification.
5.1.4 The cylinder manufacturer shall verify that the materials are in accordance with the cylinder
manufacturer specifications.
5.1.5 All materials used in the construction of the pressure containing parts of the cylinder shall
be traceable.
5.1.6 All materials shall be suitable for use at the minimum operating temperature or at –20 °C,
whichever is the lower.
5.1.7 The materials used for manufacture of the cylinder shell shall be compatible with the intended
gas service as specified in ISO 11114-1 or ISO 11114-2.
5.1.8 Contact between dissimilar metals which could result in damage by galvanic corrosion shall be
avoided.
5.2 Material types
5.2.1 Carbon and low-alloy steels
5.2.1.1 The steel used for the fabrication of gas cylinder shells shall be made in an electric furnace
or, by the basic oxygen process, shall have non-ageing properties and shall be fully killed by aluminium
and/or silicon.
5.2.1.2 Carbon steel for cold deep drawn seamless, welded, or brazed cylinder shells shall have non-
ageing properties, processed free of stretcher strain, and shall be fully killed with aluminium and/or
silicon. The chemical composition shall meet the requirements of 5.3.1.1.
5.2.1.3 Carbon steel for other welded cylinder shells shall have a chemical composition which meets
the requirements of 5.3.1.2. The maximum tensile strength shall not exceed 700 MPa.
5.2.1.4 Carbon steel for cylinder shells made from seamless steel tubing with integrally formed ends,
hot drawn, and finished shall have a chemical composition which meets the requirements of 5.3.1.3.
5.2.1.5 Low alloy steels shall conform to ISO 4706:2008, 5.9.1 or ISO 9809-1:2010, 6.1, 6.2, and 6.3
5.2.2 Aluminium and aluminium alloy
5.2.2.1 Aluminium alloys with a tensile strength greater than 500 MPa shall not be used.
5.2.2.2 Aluminium alloys used for cylinders shall conform to the material requirements of
ISO 7866:2012, 6.1 and 6.2 or ISO 20703:2006, 4.1 and 4.2, as appropriate.
5.2.2.3 Pure aluminium is permitted and shall have a minimum aluminium content of 99,0 %.
5.2.3 Austenitic stainless steels
5.2.3.1 For austenitic stainless steels, the maximum tensile strength shall not exceed 800 MPa.
4 © ISO 2015 – All rights reserved

ISO 11118:2015(E)
5.2.3.2 The cylinder manufacturer shall take into consideration the loss of material strength within the
heat affected zone of any weld.
5.2.3.3 Austenitic stainless steels for all types of cylinder shells shall conform to ISO 9809-4:2014, 6.1
and 6.2.
5.2.3.4 Due to the risk of sensitization to inter-granular corrosion resulting from hot working/welding
for each material specification and heat-treatment method, a corrosion test shall be carried out according
to ISO 3651-2 on a specimen taken from a finished cylinder.
Some grades of stainless steels can be susceptible to environmental stress corrosion cracking. Special
precautions should be taken in such cases.
5.3 Chemical compositions
5.3.1 Carbon and low-alloy steels
5.3.1.1 Carbon steels having non-aging properties for cold deep drawn welded or brazed cylinder
shells shall have the following chemical composition limits in % mass fraction.
Carbon ≤0,12
Manganese ≤0,50
Phosphorus ≤0,025
Sulfur ≤0,025
5.3.1.2 Carbon steels for welded cylinder shells other than cold deep drawn shall have the following
chemical composition limits in % mass fraction.
Carbon ≤0,25
Manganese ≤0,50
Phosphorus ≤0,025
Sulfur ≤0,025
5.3.1.3 Carbon steels for cylinders made of seamless steel with integrally formed ends, hot drawn, and
finished shall have the following chemical composition limits in % mass fraction.
Carbon ≤0,55
Manganese ≤1,70
Phosphorus ≤0,025
Sulfur ≤0,025
5.3.2 Aluminium and aluminium alloys
Aluminium and aluminium alloys shall have a maximum lead and bismuth contents not exceeding
0,003 % each.
ISO 11118:2015(E)
6 Inspection and testing
To ensure that the cylinders conform to this International Standard, they shall be subject to inspection
and testing in accordance with Clauses 9 to 11 and Annex A by an inspection body (hereinafter referred
to as “the inspector”) authorized to do so.
Equipment used for measurements, testing, and examination during production shall be maintained
and calibrated within a documented quality management system.
NOTE Evaluation of conformity can be carried out according to the regulations recognized by the
country(ies) in which the cylinders are intended to be used.
7 Design
7.1 General requirements
7.1.1 The calculation of the cylindrical wall thickness of the pressure containing parts shall be related
to the guaranteed minimum yield strength of the finished cylinder (R ).
eg
7.1.2 The design of the cylinder shell shall be such that the pressure containing parts, when subjected
to the test pressure (p ), shall not show any permanent visible deformation.
h
7.1.3 Welded aluminium and welded aluminium alloy cylinders are limited to a maximum of 60 bar
test pressure.
7.2 Calculation of pressure containing parts
The minimum thickness of the cylindrical shell of the pressure containing parts shall not be less than
any of the three values determined in 7.2 a), b), or c).
a) The minimum thickness of the cylindrical shell shall be not less than that necessary for the
minimum burst pressure to be greater than 1,6 times the test pressure (p ) and such that the
h
requirements of 9.2.4.5 and Clause 11 are met.
b) The minimum thickness of the cylindrical shell shall not be less than that calculated by the Lamé -
von Mises formula as given in Formula (1).
 
 
10 - 3 p
D FR
eg
h
 
a =  1 -   (1)
 
 
2 10
FR
eg
 
 
 
where F ≤ 0,85
c) The minimum thickness of the cylindrical shell shall not be less than that calculated by using
Formula (2) or Formula (3) as appropriate.
Formula (2) (for steel):
a = D/650 + 0,4 (2)
Formula (3) (for aluminium alloys):
a = D/300 + 0,5 (3)
NOTE It is generally assumed that p is equal to 1,5 times working pressure for compressed gases.
h
6 © ISO 2015 – All rights reserved

ISO 11118:2015(E)
7.3 Design drawings
Fully dimensioned drawing(s) of the non-refillable cylinder shall be supplied which includes the
following as a minimum:
a) material specifications for cylinder shells including, but not limited to R and R (MPa). In
eg mg
addition, the material specifications for the non-refillable sealing device shall be noted;
b) test pressure (bar);
c) minimum burst pressure (bar);
d) minimum thickness of the cylindrical shell (mm);
e) minimum water capacity (litre) (for cylinders ≤2 l, the water capacity may be reported in ml);
f) nominal cylinder outside diameter (mm);
g) dimensions of the cylinder ends (mm);
h) overall length of the cylinder (mm);
i) heat treatment (if any);
j) method of construction;
k) welding/brazing procedure designation (if any);
l) specifications for valve outlet connection or cylinder threaded connection for use (if applicable);
m) cylinder design identification;
n) design standard (i.e. ISO 11118);
o) date and revision identity of drawing;
p) manufacturers identity;
q) content and position of markings;
r) description of non-refillable sealing device that guarantees non-refillability and, if applicable,
piercing force and energy required to pierce membranes.
8 Construction and workmanship
8.1 Construction
8.1.1 Types of construction of cylinder shell
The cylinder shells shall be of seamless, welded, or brazed construction.
8.1.1.1 Seamless construction
Seamless cylinder shells shall be produced by
a) forging or drop forging from a solid ingot or billet,
b) manufacturing from seamless tube, or
c) pressing from a flat plate (cold deep drawn).
ISO 11118:2015(E)
Welding and brazing are only permitted to attach the non-refillable sealing device.
a) Welding shall be carried out only on cylinders made of weldable materials.
b) Brazing shall be carried out only on cylinders made of materials not degraded by this procedure.
8.1.1.2 Welded construction
8.1.1.2.1 General requirements
The welding of longitudinal and circumferential seams shall be by a semi-automatic or automatic process.
The longitudinal seam weld, if any, shall be of the butt type weld joint as illustrated in Figure 1 a).
The circumferential seam(s), if any, shall be butt-welded. The weld joint shall be as illustrated in
Figure 1 a), b), c), or d).
Welded joints shall have strength greater than the tensile strength of the finished cylindrical wall.
The welding procedure and operator qualifications shall include, as a minimum, welds representative
of those made in production representing the variables in the materials and the process. Requalifying
of the procedures and operators shall be required if there is a change in any of the essential variables as
specified in 8.1.1.2.2.7.
a) Butt weld joint c) Butt weld joint with backing ring
b) Offset butt weld d) Joggle butt weld
Figure 1 — Weld joints
8.1.1.2.2 Welding qualifications
8.1.1.2.2.1 General
a) All welding operators and welding procedures shall be approved by meeting the requirements of
8.1.1.2.2 through 8.1.1.2.2.9 or those given in ISO 9606-1, ISO 15613, and ISO 15614-1.
b) Records of welding operators and welding procedures qualifications shall be kept on file by the
manufacturer.
c) Weld procedure specification approval tests shall be carried out such that the welds shall be
representative of those made in production.
d) Welding operators and welding procedures shall pass the approval tests for the specific type of
work and procedure specification concerned.
8 © ISO 2015 – All rights reserved

ISO 11118:2015(E)
8.1.1.2.2.2 Materials for pressure and non-pressure containing parts
The materials used for qualification shall be the same as those specified in the procedure specification
and those used for the production.
8.1.1.2.2.3 Positions of welds
For welder qualification, the position of the part for welding shall be the same as that in the actual
manufacturing.
8.1.1.2.2.4 Welding consumables
The weld consumables shall be the same as those specified in the procedure specification, those tested
from the welders, and those used for the production.
8.1.1.2.2.5 Retesting
Where a welder fails to meet the requirements of this International Standard,
a) an immediate retest shall be carried out of two test welds of the type failed, both of which shall
meet all the requirements of the standard, or
b) a retest shall be carried out provided there is evidence that the operator has had further training
and practice to the design and procedure specification.
8.1.1.2.2.6 Period of effectiveness
A welder shall be requalified on the design if the design has not been produced by the welder for a
period of six months or more. Records of effectiveness shall be retained by the manufacturer.
8.1.1.2.2.7 Essential variables of the welding process
The procedure specification and welder qualification shall be tested when any of the following
changes are made:
a) a change to the base materials;
b) a change to the welding material;
c) a change to the weld process;
d) a change to the weld position;
e) a decrease of 30 °C or more in the minimum specified preheating temperature;
f) the omission or addition of a backing strip in single pass welds;
g) a change from multiple pass to single pass per side;
h) a change to the shielding gas or to the composition (if greater than a 15 % change in the mixture);
i) a change from a single arc to multi arc or vice versa.
8.1.1.2.2.8 Welder qualification tests
a) For longitudinal welds:
1) Bend test, root of weld;
ISO 11118:2015(E)
2) Weld tensile test.
b) For circumferential welds:
1) Macro test;
2) Weld tensile test.
c) For threaded connections to cylinder ends: Macro tests, 180° apart.
d) For welded attachments, foot rings, collars, or lugs: Macro test.
e) For fillet welds: Macro tests, 180° apart.
8.1.1.2.2.9 Acceptance
a) For bend tests:
Upon completion of the test, the test piece (weld metal and base material) shall remain uncracked.
b) For tensile tests:
The tensile strength value obtained, R , shall not be less than that guaranteed by the cylinder
ma
manufacturer regardless of the fracture location.
c) For macro tests:
The etched specimen shall be prepared to a resolution where visually, examination can occur to
determine adequate root penetration into both members as to the established design (e.g. ISO 17639).
8.1.1.3 Brazed construction
Butt weld brazed joints shall not be used.
Three-piece cylinder designs with brazed seams shall not be permitted.
Brazing shall not be used for aluminium or aluminium alloy cylinders.
Brazing materials shall be compatible with the intended gas being placed in the cylinder.
The brazing material shall have a melting point greater than 540 °C.
Brazed seams shall be assembled such as to ensure complete penetration of the brazing material
throughout the joint.
Brazed joints shall have strength greater than the tensile strength of the finished cylindrical wall.
Brazing procedures and operators shall be qualified to a written procedure (e.g. ISO 13585, EN 13134).
8.1.1.4 Attachments and openings
Attachments to the cylinder including sealing of the neck opening by welding or crimping a pierceable
metal membrane shall be by means which are not detrimental to the integrity of the cylinder. Welding
or brazing of attachments to the cylinder other than non-refillable sealing device shall be completed
prior to the final testing of the cylinder shell (see Clause 11).
There shall be no openings or attachments in the cylindrical shell.
All openings and their reinforcements shall be within an imaginary circle concentric with the centreline
axis of the cylinder. The diameter of the circle shall not exceed 80 % of the outside diameter of the
cylinder. The plane of the circle shall be perpendicular to the centreline axis of the cylinder (see Figure 2).
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ISO 11118:2015(E)
If necessary, each opening can be reinforced by a securely attached fitting, boss, pad, collar, or other
suitable means.
Material used for welded attachments and fittings shall be of weldable quality and compatible with the
cylinder material.
Material used for brazed attachments and fittings shall be of brazable quality and compatible with the
cylinder material. The minimum width of the brazed joints shall be at least four times the minimum
design shell wall thickness.
Figure 2 — Openings
8.1.2 Cylinder non-refillability
The cylinder shall be equipped with a device rendering the cylinder non-refillable. This can be
accomplished by a valve or a pierceable metal membrane in accordance with Annex A that is
permanently attached to the neck opening which, when in place, renders the cylinder non-refillable.
Replaceable sealing devices shall not be used.
8.1.3 Pressure relief devices
Where a pressure relief device is an integral part of the cylinder, the manufacturer of the cylinder shall
size the pressure relief device to have sufficient relieving capacity to prevent the rupture.
8.2 Workmanship
The quality of workmanship and construction shall be such as to ensure that cylinders are free from
defects, including at least the following:
a) the pressure containing parts shall be of uniform quality and free from surface imperfections
which could adversely affect the safe working of the cylinder;
b) before sealing the cylinder or after welding the longitudinal joint, if any, each cylinder shall be
clean, dry, and free of any loose particles;
c) after completion of all welded/brazed joints, the weld shall not have concavity, weld under-cutting,
or abrupt weld irregularity nor have any cracks or other defects;
d) if filling is part of the cylinder manufacturing
...