CEN/TC 23 - Transportable gas cylinders

This document specifies minimum requirements for the materials, design, construction, prototype testing and routine manufacturing inspections of composite gas cylinders and tubes for compressed hydrogen.
NOTE 1 Unless specified in the text, for the purposes of this document, the word “cylinder” includes tubes.
This document applies to
-   fully wrapped composite cylinders (Type 3 and Type 4)
-   hoop wrapped cylinders (Type 2)
with carbon fibres intended to be permanently mounted in a frame (e.g. bundle or trailer) with a test pressure of not less than 300 bar, with:
— non-metallic liners (for Type 4) or seamless metallic liners (for Type 2 and Type 3),
— a maximum water capacity of 3 000 l
— a maximum working pressure of 1 000 bar.
— the product of working pressure times water capacity (p x V) not exceeding 1 000 000 bar.l.
NOTE 2 A glass fibre protective layer is sometimes applied to the external surface of the cylinder

This document specifies minimum requirements concerning material, design, construction and workmanship, manufacturing processes and testing of refillable transportable welded carbon steel gas cylinders of water capacities up to and including 150 l for compressed, liquefied and dissolved gases.
For acetylene service, additional requirements for the cylinder and basic requirements for the porous material are given in EN ISO 3807. For cylinder shells for acetylene service manufactured from high frequency induction (HFI) welded steel tubes by spinning of the end, the requirements are given in Annex A.
This document is primarily applicable to industrial gases other than LPG but can also be applied for LPG. However for dedicated LPG cylinders, see EN 1442.

This document gives a list of FTSC (fire potential, i.e. “oxidizing power and flammability”, toxicity, state of the gas, and corrosiveness) codes determined according to the relevant properties of gases and of some liquids that are transported under pressure.
It does not cover material compatibility with gases which is covered by the ISO 11114 series.

No scope available

This document specifies design, type testing and marking requirements for:
a)       cylinder valves intended to be fitted to refillable transportable gas cylinders;
b)       main valves (excluding ball valves) for bundles of cylinders;
c)        cylinder valves or main valves with integrated pressure regulator (VIPR);
NOTE 1        This includes the following specific VIPR designs where:
1)  The pressure regulating system is acting as the primary valve operating mechanism (VIPR type B). This also includes designs where closure of the primary valve operating mechanism is obtained by closing the seat of the pressure regulating mechanism.
2)  The primary valve operating mechanism is located at the low-pressure side of the pressure regulating system (VIPR type C).
d)       valves for pressure drums and tubes;
which convey compressed, liquefied or dissolved gases.
NOTE 2        Where there is no risk of ambiguity, cylinder valves, main valves, VIPRs and valves for pressure drums and tubes are addressed with the collective term “valves” within this document.
This document does not apply to
—     valves for cryogenic equipment, portable fire extinguishers and liquefied petroleum gas (LPG);
—     quick-release cylinder valves (e.g. for fire-extinguishing, explosion protection and rescue applications) - requirements for quick-release cylinder valves are specified in ISO 17871 which contains normative references to this document;
—     self-closing cylinder valves and ball valves.
NOTE 3        Requirements for valves for cryogenic vessels are specified in ISO 21011 and at a regional level, e.g. in EN 1626. Requirements for LPG valves are specified in ISO 14245 or ISO 15995. Requirements for self-closing cylinder valves are specified in ISO 17879. Requirements for ball valves are specified in ISO 23826. Requirements for valves for portable fire extinguishers at a regional level are specified, for example, in the EN 3 series.
This document only covers the function of a valve as a closure. Other functions that are possibly integrated in the valve can be covered by other standards. Such standards do however not constitute requirements according to this document.
NOTE 4        Definition of and specific requirements for VIPRs in addition to those that are given in this document are specified in ISO 22435 for industrial applications or ISO 10524-3 for medical applications. Similarly, certain specific requirements for residual pressure valves (RPV) with or without a non-return function in addition to those that are given in this document are given in ISO 15996.
NOTE 5        Certain specific requirements for valves for breathing apparatus in addition to those that are given in this document are specified at a regional level, for example, in the EN 144 series. Certain specific requirements for quick-release valves for fixed fire-fighting systems in addition to those that are given in this document are specified in ISO 16003 and at a regional level, for example, in EN 12094–4.
NOTE 6        Requirements for manufacturing tests and examinations of valves covered by this document are given in ISO 14246.

This document specifies design, type test methods, marking and instruction requirements for cylinder valves with integrated pressure regulators (VIPRs) intended to be fitted to gas cylinders, pressure drums or tubes or used as a main valve for bundles of cylinders that convey compressed, liquefied or dissolved gases.
These are requirements for VIPRs that are in addition to those given in the relevant closure standard, for example, in ISO 10297 for cylinder valves, in ISO 17871 for quick-release cylinder valves, in ISO 17879 for self-closing cylinder valves or in ISO 23826 for ball valves. For ISO 17871, these requirements are only applicable to quick-release cylinder valves types B, C, D and E.
NOTE 1        If the pressure regulating system of a VIPR is acting as the primary valve operating mechanism, it is covered by the relevant closure standard, e.g. ISO 10297, ISO 17871, ISO 17879 and ISO 23826. This also includes designs where closure of the primary valve operating mechanism of a VIPR is obtained by closing the seat of the pressure regulating system.
NOTE 2        If the primary valve operating mechanism of a VIPR is located at the low-pressure side of the pressure regulating system, it is covered by the relevant closure standard, e.g. ISO 10297, ISO 17871, ISO 17879 and ISO 23826.
NOTE 3        The term “pressure receptacle” is used within this document to cover instances where no differentiation is necessary between gas cylinders, bundles of cylinders, pressure drums and tubes.
This document does not apply to VIPRs for
a)       medical applications (see ISO 10524-3);
b)       liquefied petroleum gas (LPG);
c)        cryogenic applications.
NOTE 4        Additional requirements for a VIPR with a residual pressure device (RPD) are specified in ISO 15996.
NOTE 5        Additional requirements for pressure relief valves can exist in international/regional regulations/ standards.

This document specifies the requirements for periodic inspection and testing to verify the integrity for further service of hoop-wrapped and fully-wrapped composite transportable gas cylinders and tubes, with aluminium-alloy, steel or non-metallic liners or of linerless construction (Types 2, 3, 4, and 5), intended for compressed, liquefied or dissolved gases under pressure, of water capacity from 0,5 l up to 3 000 l.
This document addresses the periodic inspection and testing of composite cylinders and tubes constructed according to ISO 11119-1, ISO 11119-2, ISO 11119-3, ISO 11119-4 or ISO 11515. It can be applied to other composite cylinders and tubes designed to comparable standards when authorized by the competent authority. As far as practicable, this document can also be applied to cylinders of less than 0,5 l water capacity when authorized by the manufacturer.
NOTE    Unless noted by exception, the use of the word “cylinder” in this document refers to both cylinders and tubes.

This document is applicable to pin-index yoke-type valve connections for medical gas cylinders, with a working pressure up to a maximum of 200 bar or test pressure up to a maximum of 300 bar, or both.
NOTE 1        This type of connection is primarily used for small cylinders (5 l or below).
NOTE 2        In this document the unit bar is used, due to its universal use in the field of technical gases. It should, however, be noted that bar is not an SI unit, and that the corresponding SI unit for pressure is Pa (1 bar = 105 Pa = 105 N/m2).
This document specifies:
—     basic dimensions;
—     requirements for alternative designs of the yoke-type valve connections;
—     dimensions and positions for the holes and pins for the outlet connections.
It also specifies the dimensions and positions for the holes and pins for the outlet connections for gases and gas mixtures.

This document specifies the following, in order to determine the corrosiveness of gases and gas mixtures so that a suitable outlet connection can be assigned to each of them:
—    for pure gases and some liquids, a complete list indicating their corrosiveness;
—    for gas mixtures, a calculation method, in the absence of experimental data, relating to the corrosiveness of each of their components.

This document specifies the minimum requirements for the materials, design, construction and workmanship, manufacturing processes, examinations and testing at time of manufacture for refillable, seamless, stainless steel gas cylinders with water capacities up to and including 150 l.
It is applicable to cylinders for compressed, liquefied and dissolved gases with a maximum actual tensile strength, Rma, of less than 1 100 MPa.
NOTE         If so desired, cylinders of water capacity between 150 l and 450 l can be manufactured to be in full conformance to this document.

This document specifies minimum requirements for the materials, design, construction, prototype testing and routine manufacturing inspections of fully wrapped composite gas cylinders for compressed, liquefied and dissolved gases.
NOTE 1   For the purposes of this document, the word “cylinder” includes tubes (seamless transportable pressure receptacles of a water capacity exceeding 150 l and of not more than 3 000 l).
This document is applicable to cylinders that comprise a liner of metallic material (welded or seamless) or non-metallic material (or a mixture thereof), reinforced by a wound composite consisting of fibres of glass, carbon or aramid (or a mixture thereof) embedded in a matrix.
This document is also applicable to composite cylinders without liners.
This document is not applicable to gas cylinders which are partially covered with fibres and commonly called “hoop wrapped” cylinders. For hoop wrapped composite cylinders, see EN 12257.
NOTE 2   This document does not address the design, fitting and performance of removable protective sleeves. Where these are fitted, they are considered separately.
This document is primarily for compressed, liquefied and dissolved gases other than LPG.
NOTE 3   For dedicated LPG cylinders, see EN 14427.

This document specifies requirements for the inspection and maintenance of valves [including ball valves and valves with integrated pressure regulator (VIPRs)] for:
a) refillable transportable gas cylinders;
b) cylinder bundles;
c) pressure drums and tubes;
which convey compressed, liquefied or dissolved gases.
This document does not apply to valves for liquefied petroleum gas (LPG).
NOTE       Where there is no risk of ambiguity, gas cylinders, cylinder bundles, pressure drums and tubes are addressed with the collective term “gas cylinders” within this document.
This document is applicable to valves reused at the time of the periodic inspection of gas cylinders, cylinder bundles, pressure drums and tubes, and can be applied at any other time, e.g. at a change of gas service (see ISO 11621).
This document does not apply to the routine inspection of valves, e.g. carried out at the time of a gas cylinder filling.

This document lists the best available acute-toxicity data of gases taken from a search of the current literature to allow the classification of gases and gas mixtures for toxicity by inhalation.
Scope of amendment
Changes to formula in clause 4.3

This document specifies requirements for the test apparatus and test procedure in order to apply oxygen pressure surges consistently to devices being tested for resistance to ignition by adiabatic compression and to materials for oxygen compatibility.

This document specifies the procedures and acceptance criteria for manufacturing tests and examinations (sometimes called "initial inspection and tests") of valves designed and type tested in accordance with ISO 10297.
This document is applicable to:
a) cylinder valves intended to be fitted to refillable transportable gas cylinders;
b) main valves (excluding ball valves) for cylinder bundles;
c) cylinder valves or main valves with integrated pressure regulator (VIPR);
d) valves for pressure drums and tubes.
NOTE       Where there is no risk of ambiguity, cylinder valves, main valves, VIPR and valves for pressure drums and tubes are addressed with the collective term “valves” within this document.
The principles of these manufacturing tests and examinations can be beneficially applied to cylinder valves type tested to national or International Standards other than ISO 10297.

This document specifies some gas compatibility test methods to evaluate plastic materials suitable for use in the manufacture of composite gas cylinder liners. It is also applicable to the evaluation of the suitability of plastic matrix materials used for Type 5 cylinders.
Some fluids like water, used for cylinders testing, can react positively or negatively when in contact with plastic liners. This compatibility issue is not covered by this document.

2019-02-18: WI changed from revision to Amendment further to same change at ISO

This document defines terms for gas cylinders.

This document gives guidance on the selection and evaluation of compatibility between non-metallic materials for gas cylinders and valves and the gas contents. It is also applicable to tubes, pressure drums and bundles of cylinders.
This document covers composite and laminated materials used for gas cylinders. It does not include ceramics, glasses and adhesives.
This document considers the influence of the gas in changing the material and mechanical properties (e.g. chemical reaction or change in physical state). The basic properties of the materials, such as mechanical properties required for design purposes (normally available from the materials supplier), are not considered. Other aspects, such as quality of delivered gas, are not considered.
The compatibility data given are related to single component gases but can be applicable to gas mixtures.
This document does not apply to cryogenic fluids (this is covered in ISO 21010).

This document specifies design, type testing, marking, manufacturing tests and examinations requirements for ball valves used as:
closures of refillable transportable gas cylinders, pressure drums and tubes;
main valves for cylinder bundles;
valves for cargo transport units [e.g. trailers, battery vehicles, multi-element gas containers (MEGCs)];
which convey compressed gases, liquefied gases and dissolved gases.
NOTE 1      In this document, the term “valve” is used with the meaning of “ball valve”.
This document does not apply to ball valves for:
oxidizing gases as defined in ISO 10156;
toxic gases (i.e. gases listed in ISO 10298 having an LC50 value ≤ 5 000 ppm
acetylene for single gas cylinders, pressure drums and tubes.
NOTE 2      The reason for the exclusion of oxidizing gases is that the use of ball valves as closures of high-pressure cylinders for oxidizing gases is known to lead to specific ignition hazards that cannot reasonably be mitigated through the ball valve design or type testing. Safety hazards concern both the ball valve itself and any downstream equipment.
NOTE 3      The reason for the exclusion of acetylene for single gas cylinders, pressure drums and tubes is that the risk of an acetylene decomposition cannot reasonably be mitigated through the ball valve design or type testing.
This document does not apply to ball valves for liquefied petroleum gas (LPG), cryogenic equipment, portable fire extinguishers and cylinders for breathing apparatus.
NOTE 4      Requirements for valves for cryogenic vessels are specified in ISO 21011.
NOTE 5      Certain specific requirements for quick-release valves for fixed fire-fighting systems in addition to those that are given in this document are specified in ISO 16003.

This document specifies definitions, dimensions and tolerances of parallel screw threads of M30 x 2, M25 x 2 and M18 x 1,5, for the connection of valves to medical and industrial gas cylinders.
This document does not contain the connection requirements for:
—    mechanical strength;
—    gas tightness;
—    capability of repeated assembly and dismounting operations (this aspect is covered in ISO 13341).

This document specifies the requirements for periodic inspection and testing of welded steel transportable pressure drums of water capacity from 150 l up to 1 000 l and up to 300 bar test pressure intended for compressed and liquefied gases.

ISO 20475:2018 specifies the requirements for the periodic inspection and testing of cylinder bundles containing compressed, liquefied and dissolved gas.
NOTE       Additional requirements for acetylene cylinder bundles are provided in Annex A.
ISO 20475:2018 also establishes general principles for the maintenance of cylinder bundles.
ISO 20475:2018 is not applicable to acetylene bundles with solvent-free acetylene cylinders.
ISO 20475:2018 excludes the requirements for cylinder bundles when they are a part of a battery vehicle. For some specific applications, e.g. offshore, additional requirements can apply.

ISO 11755:2005 specifies the requirements for inspection before, during and after the time of filling for cylinder bundles for compressed and liquefied gases, also referred to as bundles.
ISO 11755:2005 does not apply to acetylene bundles.
ISO 11755:2005 does not apply to bundles when they are a part of a battery vehicle.

ISO 10298:2018 lists the best available acute-toxicity data of gases taken from a search of the current literature to allow the classification of gases and gas mixtures for toxicity by inhalation.

This document, in conjunction with ISO 10297 and ISO 14246, specifies design, type testing, marking and manufacturing tests, and examinations requirements for quick-release cylinder valves intended to be fitted to refillable transportable gas cylinders, pressure drums and tubes which convey:
—     non-toxic;
—     non-oxidizing;
—     non-flammable; and
—     non-corrosive;
compressed or liquefied gases or extinguishing agents charged with compressed gases to be used for fire-extinguishing, explosion protection, and rescue applications.
NOTE 1  The main application of such quick-release cylinder valves is in the fire-fighting industry. However, there are other applications such as avalanche airbags, life raft inflation and similar applications.
NOTE 2  Where there is no risk of ambiguity, gas cylinders, pressure drums and tubes are addressed with the collective term "cylinders" within this document.
This document covers the function of a quick-release cylinder valve as a closure.
This document does not apply to quick-release cylinder valves for cryogenic equipment and for liquefied petroleum gas (LPG).
This document does not apply to quick-release cylinder valves if used as the main closure of portable fire extinguishers because portable fire extinguishers are not covered by transport regulation.
Quick-release cylinder valves of auxiliary refillable propellant gas cylinders used within or as part of portable fire extinguishers are covered by this document, if these cylinders are transported separately, e.g. for filling (see UN Model Regulations, Chapter 3.3, Special Provision 225, second note[1]).

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.

This International Standard specifies the requirements for design, manufacture and testing of cylinders, tubes, and other pressure vessels of steel, stainless steel, aluminium alloys or of non-metallic construction material intended for the stationary storage of gaseous hydrogen of up to a maximum water capacity of 10 000 l and a maximum allowable working pressure not exceeding 110 MPa, of seamless metallic construction (Type 1) or of composite construction (Types 2, 3 and 4) without any non-seamless load sharing metallic components, hereafter referred to as pressure vessels.
For Existing design already qualified for other applications (e.g. transportable applications) follow the requirements of Annex E.
This International Standard is not intended as a specification for pressure vessels used for solid, liquid hydrogen or hybrid cryogenic-high pressure hydrogen storage applications.

This document contains information about monolithic porous materials used in individual acetylene cylinders and in acetylene cylinder bundles in Europe. It does not claim to be exhaustive.
NOTE   Where there is any conflict between this document and any applicable regulation, the regulation always takes precedence.

This document provides specification and testing requirements for high pressure flexible hose assemblies intended to be connected to gas cylinders, bundles of cylinders or trailers (battery vehicles), and MEGCs for use when filling and emptying gas at production sites and also for customer use. This document applies to flexible hose assemblies with rated pressures up to 1 000 bar for use in the temperature range of −40 °C to +65 °C.
This document is not applicable to:
—          rubber and plastics flexible hose assemblies for welding, cutting and related processes up to 45 MPa (450 bar) for customer use (see ISO 14113);
—          high pressure flexible hose assemblies for use with medical gas systems for customer use (see ISO 21969);
—          low pressure hose assemblies for use with medical gases for customer use (see ISO 5359);
—          rubber and thermoplastic low pressure hose assemblies for welding, cutting and related processes for customer use (see ISO 3821 or ISO 12170);
—          flexible hose assemblies for cryogenic applications (see ISO 21012);
—          flexible hose assemblies for liquid petroleum gas (LPG).
NOTE       Flexible hose assembly designs which pass the type test approval described in this document can have a lower ratio of burst pressure to rated pressure than stated in other standards.

This document specifies the requirements for the design, construction, testing and initial inspection of a transportable cylinder bundle.
It is applicable to cylinder bundles containing cylinders containing compressed gas, liquefied gas and mixtures thereof. It is also applicable to cylinder bundles for acetylene. Additional requirements for acetylene cylinder bundles containing acetylene in a solvent are provided in Annex B. This document does not, however, cover acetylene cylinder bundles with solvent‐free acetylene cylinders.
This document specifies the additional requirements that apply when individual cylinders are assembled into a bundle. Unless otherwise stated, individual cylinders within a cylinder bundle conform to applicable standards for single cylinders.
This document is intended primarily for industrial gases other than liquefied petroleum gas (LPG), but it can also be used for LPG.
This document does not apply to packages in which cylinders are manifolded together in a frame that is designed to be fixed permanently to a road vehicle, to a railway wagon or to the ground as a customer storage vessel. It also does not apply to cylinder bundles that are designed for use in extreme environmental or operational conditions (e.g. offshore cylinder bundles) when additional and extraordinary requirements are imposed to maintain safety standards, reliability and performance.

This document specifies the requirements for valve protection caps and valve guards used on cylinders for liquefied, dissolved or compressed gases.
Valve protection caps and valve guards are some of the options available to protect cylinder valves, including valves with integral pressure regulators (VIPRs) during transport.
This document is applicable to valve protection caps and valve guards which inherently provide the primary protection of a cylinder valve. It can also be used to test other equipment (e.g., handling devices) attached to cylinder packages, even in cases where the cylinder valve is inherently able to withstand damage without release of the content.
This document excludes protection devices for cylinders with a water capacity of 5 l or less and cylinders whereby the protection device is fixed by means of lugs welded or brazed to the cylinder, or is welded or brazed directly to the cylinder. This document does not cover valve protection for breathing apparatus cylinders.
NOTE    Small cylinders (e.g., medical cylinders) are commonly transported in an outer-packaging (e.g., pallet) to meet transport regulations.
This document does not specify requirements that could be necessary to enable the valve protection device to be used for lifting the cylinder.

This document specifies minimum requirements for the material, design, construction and workmanship, manufacturing processes, examination and testing at the time of manufacture for refillable seamless steel gas cylinders and tubes with water capacities up to and including 450 l.
It is applicable to cylinders and tubes for compressed, liquefied and dissolved gases and for normalized or normalized and tempered steel cylinders and tubes.

This document specifies minimum requirements for the material, design, construction and workmanship, manufacturing processes, examination and testing at time of manufacture for refillable seamless steel gas cylinders and tubes with water capacities up to and including 450 l.
it is applicable to cylinders and tubes for compressed, liquefied and dissolved gases and for quenched and tempered steel cylinders and tubes with an actual tensile strength Rma ≥ 1 100 MPa.
It is not applicable to cylinders and tubes with Rma, max > 1 300 MPa for diameters >140 mm and guaranteed wall thicknesses a′ ≥ 12 mm and for cylinders and tubes with Rma, max > 1 400 MPa for diameters ≤140 mm and guaranteed wall thicknesses a′ ≥ 6 mm because, beyond these limits, additional requirements can apply.

This document specifies minimum requirements for the material, design, construction and workmanship, manufacturing processes, examination and testing at time of manufacture for refillable seamless steel gas cylinders and tubes with water capacities up to and including 450 l.
It is applicable to cylinders and tubes for compressed, liquefied and dissolved gases and for quenched and tempered steel cylinders and tubes with a maximum actual tensile strength Rma of less than 1 100 MPa.

ISO 10462 specifies requirements for the periodic inspection of acetylene cylinders as required for the transport of dangerous goods and for maintenance in connection with periodic inspection. It applies to acetylene cylinders with and without solvent and with a maximum nominal water capacity of 150 l.

This document specifies the requirements for the periodic inspection and testing of welded aluminium-alloy, carbon and stainless steel gas cylinders of water capacity from 0,5 l to 150 l intended for compressed and liquefied gas service under pressure and to verify the integrity of such gas cylinders for further service.
It also applies, as far as is practical, to cylinders of less than 0,5 l water capacity and greater than 150 l up to 450 l.
This document does not apply to the periodic inspection and testing of acetylene cylinders or composite (fully wrapped or hoop-wrapped) cylinders.
It is primarily intended for use with cylinders containing industrial gases other than liquefied petroleum gas (LPG). This document may also be applicable to LPG. Requirements for LPG applications are also provided in ISO 10464.

This document specifies the requirements for periodic inspection and testing to verify the integrity of cylinders and tubes to be re-introduced into service for a further period of time.
This document is applicable to seamless steel and seamless aluminium-alloy transportable gas cylinders (single or those that comprise a bundle) intended for compressed and liquefied gases under pressure, of water capacity from 0,5 l up to 150 l and to seamless steel and seamless aluminium-alloy transportable gas tubes (single or those that comprise a bundle) intended for compressed and liquefied gases under pressure, of water capacity greater than 150 l. It also applies, as far as practical, to cylinders of less than 0,5 l water capacity.
This document does not apply to the periodic inspection and maintenance of acetylene cylinders or to the periodic inspection and testing of composite cylinders.
NOTE       Unless noted by exception, the use of the word "cylinder" in this document refers to both cylinders and tubes.

This document specifies stamp marking of transportable gas cylinders of volumes greater than 0,12 l and up to or equal to 150 l and tubes of volumes up to or equal to 3 000 l, including:
-      steel and aluminium-alloy gas cylinders;
-      composite gas cylinders;
-      acetylene cylinders;
-      liquefied petroleum gas (LPG) cylinders (see Annex A); and
-      small cylinders (see Annex B).
Unless noted by exception, the use of "cylinder" in this document refers to the above types of cylinders.
Non-refillable cylinders are addressed by this standard.

ISO 11363-1:2018 specifies dimensions and tolerances for taper screw threads of nominal diameter 17,4 mm (designated as 17E) and 25,8 mm (designated as 25E) used for the connection of valves to gas cylinders.
ISO 11363-1:2018 does not cover the connection requirements for
-      mechanical strength,
-      gas tightness, and
-      capability of repeated assembly and dismounting operations.
Gauge inspection is covered by ISO 11363‑2.

ISO 11363-2:2017 specifies types, dimensions and principles of use of gauges, to be used in conjunction with the taper threads specified in ISO 11363-1 (i.e. 17E and 25E threads).
It provides examples of calculations for thread gauge dimensions on the large end diameter (Annex A) and draws attention to the limitations of the gauging system specified (Annex B).

ISO 15996:2017 specifies design, type testing and marking requirements for cylinder valves incorporating residual pressure devices, hereinafter referred to as residual pressure valves (RPVs). This document applies to the following types of RPVs:
a)    cylinder valves intended to be fitted to refillable transportable gas cylinders;
b)    main valves (excluding ball valves) for cylinder bundles;
c)    cylinder valves or main valves with integrated pressure regulator (VIPR);
d)    valves for pressure drums and tubes;
which convey compressed or liquefied gases.
NOTE          Where there is no risk of ambiguity, cylinders, pressure drums, tubes and cylinder bundles are addressed with the collective term "cylinder" within this document.
These requirements are in addition to those in ISO 10297.
For RPD stand-alone devices this document can also be applied.
ISO 15996:2017 does not apply to RPVs for portable fire extinguishers, cryogenic equipment, low pressure refrigerant gases (cylinder test pressure less than 50 bar), dissolved gases or liquefied petroleum gas (LPG).