Gas cylinders — Refillable welded steel cylinders containing materials for sub-atmospheric gas packaging (excluding acetylene) — Design, construction, testing, use and periodic inspection
This document specifies minimum requirements for the material, design, construction, workmanship, examination and testing at manufacture of refillable welded steel cylinders for the sub-atmospheric pressure storage of liquefied and compressed gases. It only applies to the cylinders themselves, irrespective of the materials contained therein (e.g. adsorbents, media, materials and/or gases) and other related applications. The cylinders have a test pressure not greater than 42 bar and a water capacity from 0,5 l up to and including 12 l exposed to ambient temperatures for the purpose of facilitating the sub‑atmospheric pressure storage of liquefied and compressed gases as adsorbed gases. Minimum requirements for inspection at the time of fill and periodic inspection and testing are also specified.
Bouteilles à gaz — Bouteilles en acier soudées rechargeables contenant des matériaux pour le stockage des gaz à une pression sub-atmosphérique (à l'exclusion de l'acétylène) — Conception, fabrication, essais, utilisation et contrôle périodique
Standards Content (Sample)
Gas cylinders — Refillable welded
steel cylinders containing materials
for sub-atmospheric gas packaging
(excluding acetylene) — Design,
construction, testing, use and periodic
Bouteilles à gaz — Bouteilles en acier soudées rechargeables
contenant des matériaux pour le stockage des gaz à une pression
sub-atmosphérique (à l'exclusion de l'acétylène) — Conception,
fabrication, essais, utilisation et contrôle périodique
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1 Scope . 1
2 Normative references . 1
3 Terms, definitions and symbols . 2
3.1 Terms and definitions . 2
3.2 Symbols . 2
4 Inspection and testing . 3
5 Materials and stress relieving . 3
6 Design . 4
6.1 General . 4
6.2 Calculation of cylindrical wall thickness. 5
6.3 Design of cylinder ends. 5
6.3.1 General. 5
6.3.2 Design of base concave to pressure . 5
6.4 Minimum wall thickness . 6
6.5 Pressure relief device . 7
7 Construction and workmanship . 7
7.1 General . 7
7.2 Welding qualification . 7
7.3 Welding seams of pressure containing parts . 8
7.4 Valve protection . 8
7.5 Boss threads . 8
7.6 Visual examination . 8
7.6.1 Imperfections . 8
7.6.2 Welds . 8
7.6.3 Out-of-roundness .11
7.6.4 Straightness .11
7.6.5 Verticality .11
8 Technical requirements for type approval testing (new design tests).11
8.1 General .11
8.2 Verifications and tests .12
8.3 Description of verification tests .12
8.3.1 Hydraulic burst test .12
8.3.2 Pressure cycling test .13
9 Batch tests .13
9.1 General .13
9.2 Information .13
9.3 Checks and verifications .14
9.4 Tensile test .14
9.4.2 Tensile test samples required from parent material .14
9.4.3 Tensile test samples required from welds .14
9.5 Bend test .16
9.6 Macroscopic examination of weld cross-sections .16
9.7 Radiographic examination of welds.16
10 Tests on every cylinder .17
11 Failure to meet verification and test requirements .17
12 Marking .17
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13 Certification .18
Annex A (normative) Inspection at time of fill .19
Annex B (normative) Periodic inspection and testing.21
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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
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, Subcommittee SC 3,
This second edition cancels and replaces the first edition (ISO 11513:2011), which has been technically
revised. The main changes compared to the previous edition are as follows:
— references to packing instruction P200 of the UN Model Regulations have been replaced with
packing instruction P208 as this document is referenced in only P208 of the UN Model Regulations;
— the prohibition on the use of ultrasonic testing during periodic inspection and test has been removed
from Annex B;
— the unit “weight” has been replaced with “mass” to align with ISO 80000.
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.
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This document provides a specification for the design, manufacture, use and periodic inspection and
testing of a welded steel cylinder necessary to facilitate sub-atmospheric pressure gas packaging
technology on a worldwide basis. The specifications given are based on knowledge of, and experience
with, materials, design requirements, manufacturing processes and control at manufacture of cylinders
in common use in the countries of the ISO member bodies.
The pressure shell of the cylinder is fabricated by manufacturing a cylindrical shape with a base and
welding a machined plug (boss) or semi-ellipsoidal or torispherical shape onto the open end of the shell
to form the cylinder. This method of fabrication allows for insertion of material prior to sealing the
A further objective of this document is to balance design and economic efficiency against international
acceptance and universal utility. It aims to eliminate the concerns about climate, duplicate inspections
and restrictions currently existing because of lack of definitive International Standards.
This standard has been written so that it is suitable to be referenced in the UN Model Regulations .
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INTERNATIONAL STANDARD ISO 11513:2019(E)
Gas cylinders — Refillable welded steel cylinders
containing materials for sub-atmospheric gas packaging
(excluding acetylene) — Design, construction, testing, use
and periodic inspection
This document specifies minimum requirements for the material, design, construction, workmanship,
examination and testing at manufacture of refillable welded steel cylinders for the sub-atmospheric
pressure storage of liquefied and compressed gases. It only applies to the cylinders themselves,
irrespective of the materials contained therein (e.g. adsorbents, media, materials and/or gases) and
other related applications. The cylinders have a test pressure not greater than 42 bar and a water
capacity from 0,5 l up to and including 12 l exposed to ambient temperatures for the purpose of
facilitating the sub-atmospheric pressure storage of liquefied and compressed gases as adsorbed gases.
Minimum requirements for inspection at the time of fill and periodic inspection and testing are also
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitute 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 4136, Destructive tests on welds in metallic materials — Transverse tensile test
ISO 4978, Steel sheet and strip for welded gas cylinders
ISO 5817, Welding — Fusion-welded joints in steel, nickel, titanium and their alloys (beam welding
excluded) — Quality levels for imperfections
ISO 6892-1, Metallic materials — Tensile testing — Part 1: Method of test at room temperature
ISO 7438, Metallic materials — Bend test
ISO 9809-3:2010, Gas cylinders — Refillable seamless steel gas cylinders — Design, construction and
testing — Part 3: Normalized steel cylinders
ISO 10286, Gas cylinders — Terminology
ISO 11117, Gas cylinders — Valve protection caps and valve guards — Design, construction and tests
ISO 13769, Gas cylinders — Stamp marking
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 17636-1, Non-destructive testing of welds — Radiographic testing — Part 1: X- and gamma-ray
techniques with film
ISO 17637, Non-destructive testing of welds — Visual testing of fusion-welded joints
ISO 17639, Destructive tests on welds in metallic materials — Macroscopic and microscopic examination
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3 Terms, definitions and symbols
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 10286 apply.
ISO and IEC maintain technological 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/
value corresponding to the lower yield strength, R , or 0,92 ⋅ the upper yield strength, R , or for steels
that do not exhibit a defined yield, the 0,2 % proof strength, R 0,2
heat treatment given to the drawn pressure shell by heating to a uniform temperature below the lower
critical point, AC , of the steel and cooling in a still atmosphere
Note 1 to entry: The object is to reduce the residual stresses without altering the metallurgical structure of
quantity of finished cylinders made consecutively during the same or consecutive days to the same
design, size and material specifications and cast for each pressure-containing part on the same
equipment and subjected to the same heat-treatment conditions
Note 1 to entry: Different suppliers can be used for the different pressure-containing parts within a batch, e.g.
one supplier for shells, another for plugs.
design stress factor
ratio of equivalent wall stress at test pressure, p , to guaranteed minimum yield strength, R
sub-atmospheric gas packaging
gas source package that stores and delivers gas at sub-atmospheric pressure, which includes a container
(e.g. gas cylinder and outlet valve) that stores and delivers gas at a pressure of less than 1 bar at normal
conditions of temperature and pressure
Note 1 to entry: The container can incorporate a medium in order to reduce the pressure of the gas to sub-
a calculated minimum thickness, in millimetres, of the cylindrical shell
a′ guaranteed minimum thickness, in millimetres, of the cylindrical shell (including any corrosion
allowance, see 8.1)
a guaranteed minimum thickness, in millimetres, of a concave base at the knuckle (see Figure 1 a)
a guaranteed minimum thickness, in millimetres, at the centre of a concave base (see Figure 1 a)
b calculated minimum thickness, in millimetres, of the cylinder end
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A percentage elongation after fracture
D outside diameter of the cylinder, in millimetres
d internal diameter of the cylinder, in millimetres
h outside height, in millimetres, of domed part (convex base end) (see Figure 1 a)
L length of the cylinder, in millimetres
P measured burst pressure, in bars, above atmospheric pressure, in the burst test
NOTE 1 bar = 10 Pa = 0,1 MPa.
p test pressure above atmospheric pressure, in bars
P observed pressure when cylinder starts yielding during hydraulic bursting tests, in bars, above
r inside knuckle radius, in millimetres (see Figures 1 and 2)
R guaranteed minimum yield strength in megapascals (yield strength as defined in 3.1.1), for the
finished cylinder and used for design calculation
R value of the actual yield strength in megapascals (yield strength as defined in 3.1.1), determined
by the tensile test (see 22.214.171.124)
R value of the actual tensile strength in megapascals as determined by the tensile test (see 126.96.36.199)
R guaranteed minimum tensile strength in megapascals, for the finished cylinder and used for
4 Inspection and testing
To ensure that the cylinders conform to this document, they shall be subject to inspection and testing in
accordance with Clauses 8, 9 and 10.
Inspection at the time of fill is specified in Annex A and periodic inspection and testing is specified in
Tests and examinations performed to demonstrate compliance with this document shall be conducted
using instruments calibrated before being put into service and thereafter according to an established
5 Materials and stress relieving
5.1 Materials for shells and end pressings shall conform to either ISO 4978 or ISO 9809-3.
NOTE “Materials” refers to materials in the state before transformation with regard to the manufacturing
To conform to the state of the art for modern steel manufacturing and steel grades used for pressure
purposes, the same limits on sulphur and phosphorous contents as noted in ISO 4706:2008, 5.9.1
for refillable welded steel cylinders and ISO 9809-3:2010, Table 3 shall apply in this document. The
following limits are noted:
— carbon: 0,25 % max.;
— silicon: 0,45 % max.;
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— manganese: 1,60 % max.;
— phosphorous: 0,040 % max.;
— sulphur: 0,040 % max.
5.2 All parts welded to the cylinder shall be made of compatible materials with respect to their
5.3 The welding consumables selected by the manufacturer shall be compatible with the base materials
and shall produce welds which meet the minimum strength values used in the design of the cylinder and
guaranteed by the manufacturer of the finished cylinder.
5.4 The cylinder manufacturer shall have certificates of the ladle analysis and mechanical properties of
the steel supplied for the construction of the pressure-retaining parts of the cylinder.
5.5 The manufacturer shall maintain a system of identification for the materials used in fabrication so
that all materials for pressure parts in the completed cylinder are traceable to their origin.
5.6 Grades of steel used for cylinder manufacture shall be compatible with the intended gas service,
e.g. corrosive gases, embrittling gases. See ISO 11114-1.
5.7 The drawn pressure shell and plug shall be delivered in the stress-relieved condition. Localized
stress relief of the drawn pressure shell and plug shall not be undertaken.
The quality of the welds shall be checked by non-destructive examination (NDE) or other equivalent
means to demonstrate that the cylinder is fit for the intended service. See 9.7.4.
The actual temperature of stress relief to which a type of steel is subjected for a given tensile strength
shall not deviate by more than 30 °C from the temperature specified by the manufacturer for the
5.8 The material properties of the finished cylinders shall be suitable to meet the requirements of
Clause 8 and Clause 9.
Only steel pressure receptacles resistant to hydrogen embrittlement can be used for gases assigned the
special packing provision “d” as per P208 of the UN Model Regulations .
6.1.1 The calculation of the wall thickness of the pressure-containing parts shall be related to the
guaranteed minimum yield strength, R , for the parent material in the finished cylinder.
For certain gases, additional corrosion allowances may be applicable.
6.1.2 For calculation purposes, the value of the yield strength, R , shall be limited to a maximum of
0,85 R .
6.1.3 The internal pressure upon which the minimum sidewall thickness calculation of gas cylinders is
based shall be the test pressure, p .
6.1.4 A fully dimensioned drawing including the specification of the material shall be produced.
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6.2 Calculation of cylindrical wall thickness
The guaranteed minimum thickness of the cylindrical shell shall be not less than that calculated by:
10××FR −×3 p
where F is the lesser of or 0,77.
shall not exceed 0,85.
The guaranteed minimum thickness of the cylinder shell shall also conform to 6.4.
6.3 Design of cylinder ends
NOTE Examples of typical cylinder ends are shown in Figure 1. Figure 1 a) is a typical base end concave to
pressure and Figure 1 b) is a typical end plug used to seal the top of the cylinder.
The thickness in the base of a cylinder with a convex base end shall not be less than the guaranteed
minimum wall thickness of the cylindrical shell specified in 6.2.
6.3.2 Design of base concave to pressure
When concave base ends [see Figure 1 a)] are used, the following design values are recommended:
— a ≥ 2a
— a ≥ 2a
— h ≥ 0,12 D
— r ≥ 0,075 D
The design drawing shall at least show values for a , a , h and r.
The cylinder manufacturer shall in all cases prove by the pressure cycling test given in 8.3.2 that the
design is satisfactory.
NOTE 1 An example of a typical end is shown in Figure 1 a).
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a) Illustration of cylinder base end concave to pressure
b) Boss style end plug with inlet threads
Figure 1 — Typical cylinder ends
6.4 Minimum wall thickness
6.4.1 The minimum wall thickness of the cylindrical shell including the base, a, shall be not less than
the value derived from the appropriate formula:
— for D ≤ 100 mm, a = 1,1 mm;
— for 100 mm < D ≤ 150 mm, a = 1,1 + 0,008(D − 100) mm;
— for D > 150 mm, a=+07, mm, with an absolute minimum of 1,5 mm.
6.4.2 The minimum thickness, b, of end plugs (bosses) used to seal the top of the cylinder shall be at
least twice the thickness of the cylinder sidewall, a, i.e. b ≥ 2a.
The adequacy of the end plug design shall be demonstrated by the pressure cycling test in accordance
NOTE 1 An example of a typical end plug to seal the top of the cylinder is shown in Figure 2.
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NOTE 2 The minimum wall thickness can be subject to additional requirements specified in national or
1 end plug (boss)
2 butt weld
3 cylinder shell
r knuckle radius
Figure 2 — Example of boss style end plug welded to cylinder shell
6.5 Pressure relief device
No pressure relief devices shall be included in the design.
7 Construction and workmanship
The containers in question are composed of a seamless shell with a boss welded to the open end.
The cylinder shall be produced by
a) forging or drop forging from a solid ingot or billet, or
b) pressing from a flat plate.
7.2 Welding qualification
Welding procedures shall be in accordance with ISO 15614-1. It is advisable that welders conform to
ISO 9606-1 and welding operators to ISO 14732 for all welding associated with the pressure envelope,
including the non-pressure containing parts.
Welds made in production shall be representative of those generated from the welding procedure
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7.3 Welding seams of pressure containing parts
The circumferential seam shall be butt welded as illustrated in Figure 2.
7.4 Valve protection
7.4.1 Valves shall be protected from da