EN 17339:2020

SLOVENSKI STANDARD
01-september-2020
Premične plinske jeklenke - Popolnoma obvite jeklenke in velike jeklenke za vodik
iz kompozitnih materialov z ogljikovimi vlakni
Transportable gas cylinders - Fully wrapped carbon composite cylinders and tubes for
hydrogen
Ortsbewegliche Gasflaschen - Vollumwickelte Flaschen und Großflaschen aus
Kohlenstoff-Verbundwerkstoffen für Wasserstoff
Bouteilles à gaz transportables - Bouteilles et tubes entièrement bobinées en matériaux
composites carbones pour l'hydrogène
Ta slovenski standard je istoveten z: EN 17339:2020
ICS:
23.020.35 Plinske jeklenke Gas cylinders
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 17339
EUROPEAN STANDARD
NORME EUROPÉENNE
June 2020
EUROPÄISCHE NORM
ICS 23.020.35
English Version
Transportable gas cylinders - Fully wrapped carbon
composite cylinders and tubes for hydrogen
Bouteilles à gaz transportables - Bouteilles et tubes Ortsbewegliche Gasflaschen - Vollumwickelte Flaschen
entièrement bobinées en matériaux composites und Großflaschen aus Kohlenstoff-Verbundwerkstoffen
carbones pour l'hydrogène für Wasserstoff
This European Standard was approved by CEN on 10 May 2020.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2020 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 17339:2020 E
worldwide for CEN national Members.

Contents Page
European foreword . 4
Introduction . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 8
4 Symbols . 10
5 Design and manufacture . 10
5.1 General requirements . 10
5.2 Liner . 11
5.3 Composite overwrap . 12
5.4 Finished cylinder . 13
6 Cylinder and material tests . 14
6.1 General . 14
6.2 Requirements and test methods . 14
6.3 Failure to meet test requirements . 27
7 Conformity evaluation . 27
8 Marking . 28
Annex A (normative) Prototype, design variant and production testing . 29
A.1 General . 29
A.2 Prototype testing . 29
A.2.1 General . 29
A.2.2 Definition of new design . 29
A.2.3 Prototype testing requirements . 30
A.2.4 Prototype testing certificate . 31
A.3 Design variant testing . 34
A.3.1 General . 34
A.3.2 Definition of a design variant . 34
A.3.2.1 Conditions to be satisfied . 34
A.3.2.2 Equivalent fibre . 34
A.3.2.3 Equivalent matrix . 34
A.3.2.4 Equivalent liner . 35
A.3.2.5 Cylinder variant . 35
A.3.3 Design variant test requirements . 36
A.3.4 Design variant testing certificate . 36
A.4 Production testing . 40
A.4.1 General . 40
A.4.2 Production test requirements . 40
A.4.3 Liner batch tests and inspections . 40
A.4.3.1 Metallic liner . 40
A.4.3.2 Non-metallic liner . 41
A.4.4 Composite materials batch tests and inspections . 41
A.4.5 Tests and inspections of the finished cylinder . 41
A.4.5.1 Tests . 41
A.4.5.2 Inspections . 42
A.4.6 Batch acceptance certificate . 42
Annex B (informative) Examples of prototype approval and production testing
certificates . 43
B.1 Type approval certificate – composite cylinders with metallic liners . 43
B.2 Type approval certificate – composite cylinders with non-metallic liners . 44
B.3 Design variant approval certificate – composite cylinders with metallic
liners . 45
B.4 Production test certificate . 46
Annex C (informative) Example of High velocity impact (bullet) test . 48
C.1 Procedure . 48
C.2 Criteria . 48
C.3 Parameters to monitor and record . 48
Bibliography . 49

European foreword
This document (EN 17339:2020) has been prepared by Technical Committee CEN/TC 23
“Transportable gas cylinders”, the secretariat of which is held by BSI.
This European Standard shall be given the status of a national standard, either by publication of
an identical text or by endorsement, at the latest by December 2020, and conflicting national
standards shall be withdrawn at the latest by December 2020.
Attention is drawn to the possibility that some of the elements of this document may be the
subject of patent rights. CEN shall not be held responsible for identifying any or all such patent
rights.
This document has been prepared under a mandate given to CEN by the European Commission
and the European Free Trade Association.
This document has been submitted for reference in:
— the RID; and
— the technical annexes of the ADR.
NOTE These regulations take precedence over any clause of this document. It is emphasised that
RID/ADR are being revised regularly at intervals of two years which may lead to temporary non-
compliances with the clauses of this document.
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary,
Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland,
Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden,
Switzerland, Turkey and the United Kingdom.
Introduction
The purpose of this document is to provide a specification for the design, manufacture, inspection
and testing of refillable, transportable carbon fully wrapped composite cylinders and tubes filled
with hydrogen and protected in a frame such as a bundle or a trailer.
The specifications given are based on knowledge of, and experience with, materials, design
requirements, manufacturing processes and control during manufacture of cylinders and tubes
in common use in the countries of the CEN members.
For gas cylinders covered by RID/ADR, the maximum service pressure (maximum developed
pressure at 65 °C) should not exceed the test pressure. Consequently the safety factor applies to
the test pressure since, whatever the gas, the maximum developed pressure (p ) is, in any case,
max
lower than or equal to the test pressure.
This document only covers compressed hydrogen (dedicated service), therefore, the safety factor
is applied to the maximum developed pressure at 65 °C (p ), which is the maximum accepted
max
temperature by transport regulations.
1 Scope
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 only to fully wrapped composite cylinders 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 or seamless metallic liners;
— 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 × 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.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies.
For undated references, the latest edition of the referenced document (including any
amendments) applies.
EN 13807, Transportable gas cylinders - Battery vehicles and multiple-element gas containers
(MEGCs) - Design, manufacture, identification and testing
EN ISO 75-1, Plastics - Determination of temperature of deflection under load - Part 1: General test
method (ISO 75-1)
EN ISO 75-3, Plastics - Determination of temperature of deflection under load - Part 3: High-
strength thermosetting laminates (ISO 75-3)
EN ISO 527-1, Plastics - Determination of tensile properties - Part 1: General principles (ISO 527-1)
EN ISO 527-2, Plastics - Determination of tensile properties - Part 2: Test conditions for moulding
and extrusion plastics (ISO 527-2)
EN ISO 1133-1, Plastics - Determination of the melt mass-flow rate (MFR) and melt volume-flow
rate (MVR) of thermoplastics - Part 1: Standard method (ISO 1133-1)
EN ISO 1183 (all parts), Plastics - Methods for determining the density of non-cellular plastics
EN ISO 1628-3, Plastics - Determination of the viscosity of polymers in dilute solution using capillary
viscometers - Part 3: Polyethylenes and polypropylenes (ISO 1628-3)
EN ISO 2884-1, Paints and varnishes - Determination of viscosity using rotary viscometers - Part 1:
Cone-and-plate viscometer operated at a high rate of shear (ISO 2884-1)
EN ISO 3146, Plastics - Determination of melting behaviour (melting temperature or melting range)
of semi-crystalline polymers by capillary tube and polarizing-microscope methods (ISO 3146)
EN ISO 7866, Gas cylinders - Refillable seamless aluminium alloy gas cylinders - Design, construction
and testing (ISO 7866)
EN ISO 9809-1, Gas cylinders - Design, construction and testing of refillable seamless steel gas
cylinders and tubes - Part 1: Quenched and tempered steel cylinders and tubes with tensile strength
less than 1 100 MPa (ISO 9809-1)
EN ISO 9809-2, Gas cylinders - Design, construction and testing of refillable seamless steel gas
cylinders and tubes - Part 2: Quenched and tempered steel cylinders and tubes with tensile strength
greater than or equal to 1 100 MPa (ISO 9809-2)
ISO 9809-4, 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
EN ISO 10961, Gas cylinders - Cylinder bundles - Design, manufacture, testing and inspection (ISO
10961)
EN ISO 11114-1, Gas cylinders - Compatibility of cylinder and valve materials with gas contents -
Part 1: Metallic materials (ISO 11114-1)
EN ISO 11114-2, Gas cylinders - Compatibility of cylinder and valve materials with gas contents -
Part 2: Non-metallic materials (ISO 11114-2)
EN ISO 11114-4, Transportable gas cylinders - Compatibility of cylinder and valve materials with
gas contents - Part 4: Test methods for selecting steels resistant to hydrogen embrittlement (ISO
11114-4)
EN ISO 11120, Gas cylinders - Refillable seamless steel tubes of water capacity between 150 l and
3000 l - Design, construction and testing (ISO 11120)
EN ISO 13341, Gas cylinders - Fitting of valves to gas cylinders (ISO 13341)
EN ISO 13769, Gas cylinders - Stamp marking (ISO 13769)
EN ISO 14130, Fibre-reinforced plastic composites - Determination of apparent interlaminar shear
strength by short-beam method (ISO 14130)
ISO 6721-11, Plastics - Determination of dynamic mechanical properties - Part 11: Glass transition
temperature
ISO 10618, Carbon fibre - Determination of tensile properties of resin-impregnated yarn
ASTM D 2196-10, Test methods for rheological properties of non-newtonian materials by rotational
(Brookfield) viscometer
ASTM D 2344/D 2344M-13, Test Method for Short-Beam Strength of Polymer Matrix Composite
Materials and Their Laminates
ASTM D 4018-11, Test methods for properties of continuous filament carbon and graphite fibre
tows
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
— IEC Electropedia: available at http://www.electropedia.org/
— ISO Online browsing platform: available at https://www.iso.org/obp/ui
3.1
ambient temperature
temperature of surroundings varying between 0 °C and 35 °C (for test purposes only)
3.2
autofrettage
pressure application procedure which strains the metal liner past its yield strength sufficient to
cause permanent plastic deformation, and results in the liner having compressive stresses and
the fibres having tensile stresses when at zero internal gauge pressure
[SOURCE: EN ISO 10286:2015, definition 557]
3.3
batch (of fibres, pre-impregnated fibres or components of the matrix system)
homogeneous quantity of material, identified and certified as such by the supplier
3.4
batch (of metallic liners)
quantity of liners of the same nominal diameter, thickness, length and design, made successively
from the same material cast and subjected to the same heat treatment for the same length of time
3.5
batch (of non-metallic liners)
quantity of liners of the same nominal diameter, thickness, length and design, made successively
from the same batch of materials and subjected to the same manufacturing process
3.6
batch (of finished cylinders with liners)
quantity of up to 200 finished cylinders, plus cylinders for destructive testing, of the same
nominal diameter, thickness, length and design which may contain different batches of liners
(providing the batches are nominally the same and have had the same treatments), fibres and
matrix materials
3.7
burst pressure
highest pressure reached in a cylinder or liner during a burst test
[SOURCE: EN ISO 10286:2015, definition 732, modified — “or liner” has been added.]
3.8
composite overwrap
combination of fibres and matrix
3.9
elastomer
material which at ambient temperature can be stretched repeatedly to at least twice its original
length and will return with force to approximately its original length immediately upon release
of the stress
3.10
exterior coating
layer of clear or pigmented material applied to the cylinder as protection or for cosmetic purposes
3.11
guaranteed minimum burst pressure
guaranteed minimum burst pressure shall not be less than 2 times the maximum developed
pressure at 65 °C and no less than 85 % of the value obtained during type approval.
3.12
liner
inner portion of a composite cylinder, whose purpose is both to contain the gas and transmit the
gas pressure to the composite overwrap
Note 1 to entry: It can be metallic or non-metallic, load sharing or non-load sharing
[SOURCE: EN ISO 10286:2015, definition 246 modified — Note 1 to entry has been added.]
3.13
matrix
material that is used to bind and hold the fibres in place
[SOURCE: EN ISO 10286:2015, definition 245]
3.14
non-load sharing liner
liner that contributes less than 5% of the load bearing of the overall cylinder design at nominal
burst pressure of the finished composite cylinder
Note 1 to entry: In this document, a non-load sharing liner is assumed to be a non-metallic one.
3.15
non-metallic liner
liner made from thermoplastic, thermosetting or elastomer material
Note 1 to entry: In this document, a non-metallic liner is assumed to be a non-load sharing one.
3.16
thermoplastic
plastics capable of being repeatedly softened by increase of temperature and hardened by
decrease of temperature
3.17
thermoset
plastics which, when cured by the application of heat or chemical means, change into a
substantially infusible and insoluble product
3.18
test pressure
required pressure applied during a pressure test
[SOURCE: EN ISO 10286:2015, definition 729]
3.19
working pressure
settled pressure of a compressed gas at a uniform reference temperature of 15 °C in a full gas
cylinder
[SOURCE: EN ISO 10286:2015, definition 736]
4 Symbols
p actual burst pressure of composite cylinder, in bar above atmospheric pressure
b
(1 bar = 10 Pa = 0,1 MPa.)
p burst pressure of liner, in bar above atmospheric pressure
bL
(1 bar = 10 Pa = 0,1 MPa.)
p minimum burst pressure of composite cylinder obtained during design variant approval
bmin
testing, in bar above atmospheric pressure
p hydraulic test pressure of composite cylinder, in bar above atmospheric pressure, p is
h h
equal to 1,5 × p
w
(1 bar = 10 Pa = 0,1 MPa.)
p maximum developed pressure at 65 °C, in bar above atmospheric pressure. It is assumed
max
in this document to be equal to 1,18 × p
w
(1 bar = 10 Pa = 0,1 MPa.)
p working pressure
w
5 Design and manufacture
5.1 General requirements
A fully wrapped composite gas cylinder may be manufactured with a metallic or non-metallic
liner. An optional exterior coating or fibre layers may be used to provide external protection and
when this is an integral part of the design, it shall be permanent.
The cylinder may also include additional parts (e.g. neck rings and foot rings).
Cylinders shall be designed with one or two openings along the central axis only.
The cylinders covered by this document shall be permanently mounted in a bundle according to
EN ISO 10961 or a trailer/MEGCs according to EN 13807.
5.2 Liner
5.2.1 Metallic liners
Metallic liners shall be manufactured in accordance with the relevant sections of:
Type of metallic liner Related Standard
a) seamless steel liners: EN ISO 9809-1, EN ISO 9809-2 or EN
ISO 11120, as appropriate;
b) seamless stainless steel liners: ISO 9809-4;
c) seamless aluminium alloy liners: EN ISO 7866

The relevant sections are those covering materials, thermal treatments, neck design, construction
and workmanship and mechanical tests.
The liner material shall be compatible with hydrogen as determined by EN ISO 11114-1 and
EN ISO 11114-4.
NOTE This excludes the design requirements, since these are specified by the manufacturer for the
design of the composite cylinder. For liners with water capacity above 150 l manufactured of stainless steel
or aluminium alloy, the relevant sections of the appropriate standard also apply.
5.2.2 Non-metallic liners
A cylinder with a non-metallic liner shall be designed as if the liner will be non-load sharing. The
liner material shall be compatible with hydrogen as determined by EN ISO 11114-2 or
demonstrated by suitable testing.
Where a metal end boss is used in a non-metallic liner, it shall be considered part of the liner
material and shall fulfil the material requirements specified in the relevant standard, as listed in
5.2.1. Other materials are acceptable if hydrogen compatibility is demonstrated by testing
according to EN ISO 11114-4 or if it is accepted by design standards (e.g. EN ISO 7866).
The drawing of the liner shall include the specification of the material and material properties of
the boss. The following material properties of the boss shall be specified in the design:
a) minimum yield stress;
b) minimum tensile strength;
c) minimum elongation;
d) compatibility with hydrogen as determined by EN ISO 11114-1.
The metal end boss bearing the cylinder thread shall be designed to withstand the torque applied
in fitting the valve to the cylinder and the tests specified in Test 13 (for taper threads only, see
6.2.13) and Test 14 (see 6.2.14).
5.2.3 Design drawing
A fully dimensioned drawing of the liner shall be supplied which includes the specification of the
material and material properties. Material and liner properties to be specified on the drawing are:
a) for metallic liners:
— minimum yield stress;
— minimum tensile strength;
— minimum elongation;
— minimum burst pressure;
— compatibility with hydrogen as determined by EN ISO 11114-1.
b) for non-metallic liners:
1) density;
— melting point, as determined by:
— EN ISO 3146 for thermoplastics; or
— EN ISO 75-1 and EN ISO 75-3 for thermoset materials;
— glass transition temperature as determined by differential scanning calorimetry;
— composition;
— compatibility with hydrogen as specified by EN ISO 11114-2 or demonstrated by
suitable testing
— end boss design in accordance with 5.2.2.
5.2.4 Design of ends
The external diameter and thickness of the formed neck end of the liner shall be designed to
withstand the torque applied in fitting the valve to the cylinder and the tests specified in Test 13
(for taper threads only, see 6.2.13) and Test 14 (see 6.2.14).
5.2.5 Neck ring
When a neck ring is provided, it shall be of a material compatible with that of the cylinder, and
shall be securely attached by an appropriate method to the liner (or cylinder for cylinders without
liner) or boss material.
5.3 Composite overwrap
5.3.1 Materials
Material requirements for the fibre and matrix or the pre-impregnated material shall be as
specified by the cylinder manufacturer.
5.3.2 Winding
Appropriate procedures shall be defined for the winding and curing process to ensure good
repeatability and traceability.
Parameters to be specified and monitored are:
a) composite overwrap component percentages;
b) batch numbers of the material used as defined in 3.3 to 3.6;
c) number of strands used;
d) winding tension per strand (if applicable);
e) winding speed(s);
f) winding angle and/or pitch for each layer;
g) resin bath temperature range (if applicable);
h) temperature of the strand before consolidation (if applicable);
i) number and order of layers;
j) procedure used to obtain correct impregnation (e.g. wet winding or pre-impregnation);
k) polymerisation cycle (if applicable);
l) polymerisation process (e.g. thermal cycling, ultrasonic, ultraviolet or radiation).
For thermal polymerisation, the temperature and the length of the polymerisation cycle of the
resin system shall be such that they do not adversely affect the mechanical characteristics of the
liner. In addition, tolerances for holding time and temperature at each stage shall be defined.
5.4 Finished cylinder
5.4.1 Design drawings
A fully dimensioned drawing of all parts that constitute the finished cylinder shall be supplied.
The design drawing shall include tolerances on all dimensions, including out-of-roundness and
straightness.
The drawing shall include the specification of the material(s), the material properties and the
reinforcement pattern. The specifications and the reinforcement patterns may be given in a
technical specification enclosed with the drawing.
The details of a permanently applied exterior coating, if it is an integral part of the design, shall
be defined.
The test pressure, autofrettage pressure (if applicable) and minimum burst pressure for the
design shall be specified.
Any special characteristics or special limitations (e.g. design life, vacuum suitability and/or
maximum fitting torque restrictions) shall be stated.
5.4.2 Autofrettage
Internal pressurization to autofrettage pressure of cylinders with metallic liners can be part of
the manufacturing process; if so this operation shall be executed after polymerisation of the
composite for thermosetting resins or after the consolidation process for thermoplastics.
During the autofrettage operation, the parameters to be recorded are:
a) autofrettage pressure;
b) length of application of the autofrettage pressure;
c) expansion at autofrettage pressure;
d) permanent expansion after autofrettage.
If autofrettage is used, a check shall be made on all cylinders that the procedure has been
effectively performed.
5.4.3 Manufacturing requirements for the finished cylinder
The internal and external surfaces of the finished cylinder shall be free of defects which can
adversely affect the safe working of the cylinder. In addition, there shall be no visible foreign
matter present inside the cylinder (e.g. resin, swarf or other debris).
NOTE ISO 9809-1, ISO 9809-2, ISO 9809-3 and ISO 7866 provide guidelines on possible defects in
metallic liners. For composite cylinders, ISO 11623 contains information on possible defects.
6 Cylinder and material tests
6.1 General
This clause describes tests to be conducted on cylinders, cylinder liners and the materials used in
manufacture of cylinders for prototype testing of new cylinder designs, design variant testing and
production testing. The tests listed can be required or optional, as identified in the schedule of
testing and inspections in Annex A.
No tests shall be performed with a removable protective sleeve fitted to the cylinder.
Precautions should be taken to avoid blistering and collapse, manufacturers's instructions should
provide guidelines in order to do so.
6.2 Requirements and test methods
6.2.1 Test 1 – Composite material tests, including adhesives (where applicable)
6.2.1.1 Procedure
Tests on the composite materials to establish their mechanical properties shall be carried out in
accordance with:
a) carbon fibre tensile properties: ISO 10618 or ASTM D 4018-11;
b) shear properties: EN ISO 14130 or ASTM D 2344/D 2344M-13;
c) matrix properties:
1) glass transition temperature: ISO 6721-11;
2) heat distortion temperature: EN ISO 75-3;
3) viscosity: EN ISO 1628-3 for thermoplastics; EN ISO 2884-1 or ASTM D 2196-10 for
thermosets.
The glass transition temperature (T ) shall be at least 85 °C. T shall be verified during design type
g g
approval.
Equivalent tests in accordance with alternative standards or test specifications may be applied.
6.2.1.2 Criteria
The mechanical properties shall meet the minimum requirements for the design as specified by
the cylinder manufacturer.
6.2.2 Test 2 – Liner material tests
6.2.2.1 Procedure
Tests on the liner material shall be carried out for:
a) seamless steel – as described in EN ISO 9809-1, EN ISO 9809-2 or EN ISO 11120, as
appropriate;
b) seamless stainless steel – as described in ISO 9809-4;
c) seamless aluminium alloy – as described in EN ISO 7866;
d) non-metallic materials:
1) thermoplastics:
i) melting point – EN ISO 3146;
ii) density – EN ISO 1183;
iii) melting flow index – EN ISO 1133-1;
2) thermosets and elastomerics:
i) elongation at break – EN ISO 527-1 and EN ISO 527-2;
ii) tensile strength – EN ISO 527-1 and EN ISO 527-2;
iii) density – EN ISO 1183.
Equivalent tests in accordance with alternative standards or test specifications may be applied.
6.2.2.2 Criteria
The mechanical properties shall meet the minimum requirements for the design as specified by
the manufacturer.
6.2.3 Test 3 – Liner burst test at ambient temperature (for metallic liners only)
6.2.3.1 Procedure
The hydraulic burst test shall be carried out as defined in EN ISO 9809-1 or EN ISO 7866 as
appropriate.
6.2.3.2 Criteria
a) burst pressure of the liner (p ) shall be equal to or greater than the minimum design burst
bl
pressure, as specified in 5.2.3;
b) burst initiation shall be in the cylindrical part, except in cases where the liner length is less
than 3 times the outside diameter, and the liner shall remain in one piece.
6.2.3.3 Parameters to monitor and record
a) burst pressure;
b) number of pieces;
c) failure mode description (e.g. pictures);
d) pressure/time curve or pressure/volume curve.
6.2.4 Test 4 – Pressure test of finished cylinders at ambient temperature
6.2.4.1 Procedure
Where cylinders are subjected to autofrettage, the pressure test may immediately follow or be
part of the autofrettage operation.
When carrying out the pressure test, a suitable fluid (e.g. water) shall be used as the test medium.
The fluid pressure in the cylinder shall be increased at a controlled rate until the test pressure
(p ) is reached. The cylinder shall remain at the test pressure (p ) for at least 30 s for water
h h
capacities up to 150 l and at least 2 min for water capacities above 150 l.
The limit deviation on attaining test pressure shall be + 3 % - 0 % of test pressure (p ).
h
Alternatively a pneumatic pressure test can be used provided that appropriate measures are
taken to ensure safe operation and to contain any energy that can be released, which is
considerably more than in the hydraulic test.
6.2.4.2 Criteria
a) pressure shall remain steady;
b) there shall be no leaks;
c) after the test, the cylinder shall show no visible permanent deformation.
6.2.4.3 Parameters to monitor during the test
Parameters to monitor during the test are the following:
— the pressure;
— the volumetric expansion.
6.2.5 Test 5 – Cylinder burst test
6.2.5.1 Procedure
The hydraulic pressure burst test shall be carried out using a test rig, which allows pressure to be
increased at a controlled way. The new cylinders from a given type shall be pressurized with the
same machine set up.
The test shall be carried out in ambient conditions and the temperature on the external surface
of the cylinder shall be maintained between 5 °C and 30 °C. The rate of pressurization shall be
such as the test duration is at least 1 min 30 s.
The cylinder shall be pressurized at a controlled rate until failure. The pressure against time curve
or pressure against volume curve shall be plotted.
The maximum pressure achieved during the test shall be recorded as the burst pressure.
6.2.5.2 Criteria
The burst pressure shall be greater than, or equal to, the manufacturer’s minimum specified
design burst pressure and 2,0 × maximum developed pressure.
6.2.5.3 Parameters to monitor and record
a) Burst pressure;
b) number of pieces;
c) description of failure;
d) pressure/time curve or pressure/volume curve.
6.2.6 Test 6 – Resistance to pressure cycles at ambient temperature
6.2.6.1 For non-limited life
6.2.6.1.1 Procedure
The cycle test shall be carried out using a test rig, which allows pressure to be increased and
decreased at a controlled rate and automatically suspends the test when the cylinder has failed,
either by leakage or rupture.
The test shall be carried out with a non-corrosive liquid subjecting the cylinder to successive
reversals at an upper cyclic pressure equal to the maximum developed pressure at 65 °C (p ).
max
The value of the lower cyclic pressure shall not exceed 10 % of the upper cyclic pressure or
maximum of 30 bar.
The cylinder shall actually experience the maximum and minimum cyclic pressures during this
test.
The cycle tests shall be carried out in ambient conditions and the temperature on the outside
surface of the cylinder shall not exceed 50 °C during the test. The frequency of reversals of
pressure shall not exceed 5 cycles per minute.
The temperature of the external surface of the cylinder shall be monitored at least twice a day.
The number of cycles achieved during the test shall be recorded.
After completion of this test, the cylinder shall then be destroyed (e.g. by bursting), or made
incapable of holding pressure.
6.2.6.1.2 Criteria
The cylinder shall withstand 15 000 cycles up to maximum developed pressure at 65 °C
(p = 1,18 × p ) without failure.
max w
6.2.6.1.3 Parameters to monitor and record
a) Temperature of the cylinder;
b) number of cycles achieving upper cyclic pressure;
c) minimum and maximum cyclic pressures;
d) cycle frequency;
e) test medium used;
f) mode of failure, if appropriate.
6.2.6.2 For limited life
6.2.6.2.1 Procedure
This test shall be conducted in accordance with the procedure as described in 6.2.6.1 and consists
of two parts run sequentially and continuously. Different criteria apply to the two parts as shown
in Table 1.
After completion of this test, the cylinder shall then be destroyed (e.g. by bursting), or made
incapable of holding pressure.
6.2.6.2.2 Criteria
The cylinders shall withstand N pressurization cycles to maximum developed pressure at 65 °C
(p = 1,18 × p ) for hydrogen service without failure by burst or leakage, where:
max w
N = y × 500 cycles per year of design life;
y is the number of years of design life;
y shall be a whole number which is not less than 15 years.
The test shall continue for a further N cycles, or until the cylinder fails by leakage, whichever is
the sooner. In either case, the cylinder shall be deemed to have passed the test. However, should
failure during this second part of the test be by burst, then the cylinder shall have failed the test
(see Table 1).
Table 1 — Test 6 criteria
1st part 2nd part
Number of cycles 0 to N N to 2N but 2N no more than 30 000
Criteria No leakage/burst = Pass
No leakage or burst Leakage = Pass
Pass 1st part Burst = Fail
6.2.6.2.3 Parameters to monitor and record
a) Temperature of the cylinder;
b) number of cycles, achieving upper cyclic pressure;
c) minimum and maximum cyclic pressures;
d) cycle frequency;
e) test medium used;
f) mode of failure, if any.
6.2.7 Test 7 - Exposure to elevated temperature
6.2.7.1 Procedure
For a design service life of up to 20 years, two cylinders shall be hydraulically pressurized to
maximum developed pressure at 65 °C (p ), and shall be maintained at this pressure for 1 000 h.
max
For a design service life greater than 20 years, including non-limited life, the test shall run for
2 000 h.
The test shall be conducted at 70 °C ± 5 °C and a relative humidity of more than 50 %. After this
test, the cylinders shall be subjected to Test 5 (see 6.2.5).
6.2.7.2 Criteria
The burst pressure shall be greater than or equal to the guaranteed minimum burst pressure.
6.2.7.3 Parameters to monitor and record
a) Measurement of the water capacity before and after test;
b) temperature and relative humidity at least twice a day;
c) cylinder pressure at least twice a day;
d) burst pressure.
6.2.8 Test 8 - Blunt impact test
6.2.8.1 Procedure
For all cylinders, one empty cylinder, shall be subjected to two impacts (see Figure 1 and 2):
a) one at an angle of 90° to the cylinder sidewall midway between the ends;
b) one at an angle of 45° to strike the shoulder of the cylinder (mid arc length at the dome).
The impact can be conducted by dropping a suitable weight or by a pendulum impact. The
cylinder shall be secured to ensure it does not move during the impact. The impactor shall be
made from a steel bar and have a diameter of between 110 mm and 120 mm.
An impactor with a potential energy of 1200 J shall strike the cylinder at the positions identified
above.
The frame itself is not necessarily an adequate solution to protect the cylinder and tube from
flying objects on the road. If it is considered that the cylinders will be impacted with an energy
greater than 1200 J, either a high velocity impact (bullet) test as specified in Annex C should be
carried out, or the cylinders should be adequately protected e.g. with steel plates.
It shall be specified in the marking if a high velocity (bullet) test has not been performed.
Key
1 steel
Figure 1 — Blunt impactor
Figure 2 — Blunt impact locations
The cylinder shall then be subjected to the appropriate ambient cycle test (Test 6) as described
in 6.2.6.
6.2.8.2 Parameters to monitor
a) visual appearance after each impact – record position and dimensions of impact damage;
b) parameters
6.2.8.3 Criteria
The cylinders shall withstand 3 000 pressurization cycles at maximum developed pressure at 65°
C (p ) without failure by burst or leakage. The test shall continue for a further 15 000 cycles, or
max
until the cylinder fails by leakage, whichever is the sooner. In either case, the cylinder shall be
deemed to have passed the test. However, if failure during this second part of the test is by burst,
then the cylinder shall have failed the test.
6.2.9 Test 9 – Flawed cylinder test
6.2.9.1 Procedure
Two flaws, one longitudinal and the other transverse, shall be made on each of two cylinders in
the central part along two planes forming an angle of approximately 120° (see Figure 3). One
finished cylinder shall have flaws cut into the composite of the tube sidewall in the longitudinal
direction.
The flaws shall be greater than the visual inspection limits as specified by the manufacturer. As a
minimum, the flaw length and depth shall be:
a) for cylinders up to 0,6 m diameter, one flaw (longitudinal) shall be 25 mm long and 1,25 mm
in depth and a second flaw (transversal) shall be 200 mm long and 0,75 mm in depth; and
b) for cylinders of 0,6 m diameter and larger, one flaw (longitudinal) shall be 130 mm long and
2,5 mm in depth and a second flaw (transversal) shall be 1 000 mm long and 1,5 mm in depth.

Key
1 1 mm wide
2 wrap
3 liner
Figure 3 — Flaw detail
After introducing the flaws, one of the two cylinders shall be subjected to Test 5 (see 6.2.5
Cylinder burst test). The other cylinder shall b
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