Bsi bs en 12245 2009 + a1 2011

BS EN 12245 2009 ICS 23 020 30 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW BRITISH STANDARD Transportable gas cylinders — Fully wrapped composite cylinders Incorporating cor[.]

National foreword

This British Standard is the UK implementation of

EN 12245:2009+A1:2011, incorporating corrigendum June 2010 It supersedes BS EN 12245:2009 which is withdrawn

The start and finish of text introduced or altered by amendment is indicated in the text by tags Tags indicating changes to CEN text carry the number of the CEN amendment For example, text altered by CEN amendment A1 is indicated by !"

The UK participation in its preparation was entrusted by Technical Committee PVE/3, Gas containers, to Subcommittee PVE/3/3, Transportable gas containers – Cylinder design, construction and testing at the time of manufacture

A list of organizations represented on this committee can be obtained

on request to its secretary

This publication does not purport to include all the necessary provisions of a contract Users are responsible for its correct application

Compliance with a British Standard cannot confer immunity from legal obligations.

This British Standard

was published under the

authority of the Standards

Policy and Strategy

Committee on 28 February

2009

© The British Standards

Institution 2012 Published by

BSI Standards Limited 2012.

Amendments/corrigenda issued since publication Date Comments

31 August 2010 Implementation of CEN corrigendum June 2010

Addition of Note 1 in Clause 7

30 April 2012 Implementation of CEN amendment A1:2011

EUROPÄISCHE NORM

English Version

Transportable gas cylinders - Fully wrapped composite cylinders

Bouteilles à gaz transportables - Bouteilles entièrement

bobinées en matériaux composites

Ortsbewegliche Gasflaschen - Vollumwickelte Flaschen

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, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom

EUROPEAN COMMITTEE FOR STANDARDIZATION

C O M I T É E U R O P É E N D E N O R M A L I S A T I O N

E U R O P Ä I S C H E S K O M I T E E FÜ R N O R M U N G

Management Centre: Avenue Marnix 17, B-1000 Brussels

© 2011 CEN All rights of exploitation in any form and by any means reserved

worldwide for CEN national Members

Ref No EN 12245:2009+A1:2011: E

Contents

Foreword 4



Introduction 5



1





2





3





3.1





3.2





4





4.1





4.2





4.2.1





4.2.2





4.2.3





4.2.4





4.2.5





4.3





4.3.1





4.3.2





4.3.3





4.4





4.4.1





4.4.2





4.4.3





4.4.4





5





5.1





5.2





5.2.1





5.2.2





5.2.3





5.2.4





5.2.5





5.2.6





5.2.7





5.2.8





5.2.9





5.2.10





5.2.11





5.2.12





5.2.13





5.2.14





5.2.15





5.2.16





5.2.17





5.2.18





5.2.19





5.3





5.3.1





5.3.2





6





7





8





Annex A (normative) Prototype, design variant and production testing 34



A.1





A.2





A.3





A.4





Annex B (informative) Examples of prototype approval and production testing certificates 45



B.1





B.2





B.3





B.4





B.5





Bibliography 51



Foreword

This document (EN 12245:2009+A1:2011) 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 May 2012, and conflicting national standards shall be withdrawn at the latest by May 2012

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 includes Corrigendum 1 issued by CEN on 2 June 2010 and Amendment 1 approved

by CEN on 27 September 2011

This document supersedes !EN 12245:2009"

The start and finish of text introduced or altered by amendment is indicated in the text by tags

!"

The modifications of the related CEN Corrigendum have been implemented at the appropriate places

in the text and are indicated by the tags ˜ ™

This document has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association, and supports essential requirements of !EU Directive 2008/68/EC"

According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom

1 Scope

This European Standard specifies minimum requirements for the materials, design, construction, prototype testing and routine manufacturing inspections of composite gas cylinders for compressed, liquefied and dissolved gases

NOTE 1 For the purposes of this European Standard, the word “cylinder” includes tubes (seamless transportable pressure receptacles of a water capacity exceeding 150 litres and of not more than 3 000 litres) This European Standard 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 European Standard is also applicable to composite cylinders without liners

This European Standard 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 European Standard does not address the design, fitting and performance of removable protective sleeves Where these are fitted, they should be considered separately

This European Standard is primarily for industrial gases other than LPG but may also be applied to LPG

NOTE 3 For dedicated LPG cylinders, see EN 14427

2 Normative references

The following referenced documents are indispensable for the application 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 720-2, Transportable gas cylinders — Gases and gas mixtures — Part 2: Determination of

flammability and oxidizing potential of gases and gas mixtures

EN 1964-1, Transportable gas cylinders — Specification for the design and construction of refillable

transportable seamless steel gas cylinders of water capacities from 0,5 litre up to and including 150 litres — Part 1: Cylinders made of seamless steel with an R m value of less than 1100 MPa

EN 1964-2, Transportable gas cylinders — Specification for the design and construction of refillable

transportable seamless steel gas cylinders of water capacities from 0,5 litre up to and including 150 litres — Part 2: Cylinders made of seamless steel with an R m value of 1100 MPa and above

EN 1964-3, Transportable gas cylinders — Specification for the design and construction of refillable

transportable seamless steel gas cylinders of water capacities from 0,5 litre up to and including 150 litres — Part 3: Cylinders made of seamless stainless steel with an Rm value of less than 1100 MPa

EN 1975, Transportable gas cylinders — Specification for the design and construction of refillable

transportable seamless aluminium and aluminium alloy gas cylinders of capacity from 0,5 litre up to

150 litres

EN 12862, Transportable gas cylinders — Specification for the design and construction of refillable

transportable welded aluminium alloy gas cylinders

EN 13322-1, Transportable gas cylinders — Refillable welded steel gas cylinders — Design and

construction — Part 1: Carbon steel

EN 13322-2, Transportable gas cylinders — Refillable welded steel gas cylinders — Design and

construction — Part 2: Stainless steel

EN 14638-1, Transportable gas cylinders — Refillable welded receptacles of a capacity not exceeding

150 litres — Part 1: Welded austenitic stainless steel cylinders made to a design justified by experimental methods

EN ISO 11114-1, Transportable gas cylinders — Compatibility of cylinder and valve materials with gas

contents — Part 1: Metallic materials (ISO 11114-1:1997)

EN ISO 11114-2, Transportable gas cylinders — Compatibility of cylinder and valve materials with gas

contents — Part 2: Non-metallic materials (ISO 11114-2:2000)

EN ISO 11114-3, Transportable gas cylinders — Compatibility of cylinder and valve materials with gas

contents — Part 3: Autogenous ignition test in oxygen atmosphere (ISO 11114-3:1997)

EN ISO 11114-4, Transportable gas cylinders — Compatibility of cylinder and valve materials with gas

contents — Part 4: Test methods for selecting metallic materials resistant to hydrogen embrittlement (ISO 11114-4:2005)

EN ISO 11120, Gas cylinders — Refillable seamless steel tubes for compressed gas transport, of

water capacity between 150 l and 3000 l — Design, construction and testing (ISO 11120:1999)

EN ISO 13341, Transportable gas cylinders — Fitting of valves to gas cylinders (ISO 13341:1997)

EN ISO 13769, Gas cylinders — Stamp marking (ISO 13769:2002)

ISO 75-1, Plastics — Determination of temperature of deflection under load — Part 1: General test

method

ISO 75-3, Plastics — Determination of temperature of deflection under load — Part 3: High-strength

thermosetting laminates and long-fibre-reinforced plastics

ISO 175, Plastics — Methods of test for the determination of the effects of liquid chemicals

ISO 527-1, Plastics — Determination of tensile properties — Part 1: General principles

ISO 527-2, Plastics — Determination of tensile properties — Part 2: Test conditions for moulding and

ISO 1628-3, Plastics — Determination of the viscosity of polymers in dilute solution using capillary

viscometers — Part 3: Polyethylenes and polypropylenes

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 3146, Plastics — Determination of melting behaviour (melting temperature or melting range) of

semi-crystalline polymers by capillary tube and polarizing-microscope methods

ISO 3341, Textile glass — Yarns — Determination of breaking force and breaking elongation

ISO 8521, Plastics piping systems — Glass-reinforced thermosetting plastics (GRP) pipes —

Determination of the apparent initial circumferential tensile strength

ISO 10156, Gases and gas mixtures — Determination of fire potential and oxidizing ability for the

selection of cylinder valve outlets

ISO 10618, Carbon fibre — Determination of tensile properties of resin-impregnated yarn

ISO 14130, Fibre-reinforced plastic composites — Determination of apparent interlaminar shear

strength by short-beam method

ISO 15512, Plastics — Determination of water content

ASTM D 2196-86, Test methods for rheological properties of non-newtonian materials by rotational

(Brookfield) viscometer

ASTM D 2290-92, Test method for apparent tensile strength of ring or tubular plastics and reinforced

plastics by split disk method

ASTM D 2291-83, Fabrication of ring test specimens for glass-resin composites

ASTM D 2343-03, Test Method for Tensile Properties of Glass Fiber Strands, Yarns, and Rovings

Used in Reinforced Plastics

ASTM D 2344-84, Test method for apparent interlaminar shear strength of parallel fiber composites

by short beam method

ASTM D 3418-99, Standard test method for transition temperature of polymers by differential

scanning calorimetry

ASTM D 4018-93, Test methods for tensile properties of continuous filament carbon and graphite fibre

tows

3 Terms, definitions and symbols

For the purposes of this European Standard, the following terms, definitions and symbols apply

3.1 Terms and definitions

3.1.3

batch (of fibres, pre-impregnated fibres or components of the matrix system)

homogeneous quantity of material, identified and certified as such by the supplier

3.1.4

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

3.1.5

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

3.1.6

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

3.1.7

batch (of finished cylinders with no liners)

production quantity of up to 200 finished cylinders, plus cylinders for destructive testing, of the same nominal diameter, thickness, length and design

fully wrapped cylinder

cylinder reinforced by wrapping to take both circumferential and longitudinal stress

non-load sharing liner

liner that contributes less than 5 % of the load bearing of the overall cylinder design at test pressure, and is intended only to prevent diffusion of the contained gas

3.1.16

non-metallic liner

liner made from thermoplastic, thermosetting or elastomer material

3.1.17

cylinder without liner

cylinder having no liner and consisting wholly of the composite winding

plastics which, when cured by the application of heat or chemical means, change into a substantially

infusible and insoluble product

3.2 Symbols

pb actual burst pressure of composite cylinder, in bar 1) above atmospheric pressure

pbL burst pressure of liner, in bar 1) above atmospheric pressure

pbmin minimum burst pressure of composite cylinder obtained during design variant approval

testing, in bar 1) above atmospheric pressure

ph hydraulic test pressure of composite cylinder, in bar 1) above atmospheric pressure

pmax maximum developed pressure at 65 °C, in bar 1) above atmospheric pressure

4 Design and manufacture

4.1 General

A fully wrapped composite gas cylinder may be manufactured with a metallic or non-metallic liner or without a liner Cylinders without a liner may be manufactured from two parts joined together with adhesive An optional exterior coating may be used to provide external protection and when this is an integral part of the design shall be permanent

The cylinder may also include additional parts (e.g rings and bases)

Cylinders shall be designed with one or two openings along the central axis only

4.2 Liner

4.2.1 Metallic liners

Metallic liners shall be manufactured in accordance with the relevant sections of:

a) seamless steel liners: EN 1964-1 or EN 1964-2, as appropriate;

1) 1 bar = 105 Pa = 0,1 MPa

b) seamless stainless steel liners: EN 1964-3;

c) seamless aluminium alloy liners: EN 1975;

d) welded steel liners: EN 13322-1 or prEN 14638-3, as appropriate;

e) welded stainless steel liners: EN 13322-2 or EN 14638-1, as appropriate;

f) welded aluminium liners: EN 12862;

g) steel tubes (i.e > 150 l): EN ISO 11120

The relevant sections are those covering materials, thermal treatments, neck design, construction and workmanship and mechanical tests

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, aluminium

or welded steel, the relevant sections of the appropriate standard also apply

The liner material shall be compatible with the gases intended to be used as determined by

EN ISO 11114-1 and EN ISO 11114-4

4.2.2 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 the gases intended to be used as determined by EN ISO 11114-2 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 4.2.1

The drawing of the liner shall include the specification of the material and material properties of the boss Important material properties shall be specified in the design and are those such as:

a) minimum yield stress;

b) minimum tensile strength;

c) minimum elongation of the boss material;

d) compatibility with the contained gas 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 16 (see 5.2.16) and Test 17 (see 5.2.17)

4.2.3 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:

1) minimum yield stress;

2) minimum tensile strength;

3) minimum elongation;

4) minimum burst pressure;

5) compatibility with the contained gas as determined by EN ISO 11114-1

b) for non-metallic liners:

1) density;

2) melting point, as determined by:

i) ISO 3146 for thermoplastics; or

ii) ISO 75-1 and ISO 75-3 for thermoset materials;

3) auto-ignition temperature in oxygen as determined by EN ISO 11114-3 (for cylinders

intended for air and oxidising gases (see ISO 10156 for definition of oxidising gases));

4) glass transition temperature as determined by differential scanning calorimetry;

5) composition;

6) compatibility with the contained gas as determined by EN ISO 11114-2;

7) end boss design in accordance with 4.2.2

4.2.4 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 16 (see 5.2.16) and Test 17 (see 5.2.17)

4.2.5 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 a method appropriate to the liner (or cylinder for cylinders without liner) or boss material

Parameters to be specified and monitored are:

a) composite overwrap component percentages;

b) batch numbers of the material used as defined in 3.1.3;

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

4.3.3 Cylinders without liners comprising two or more parts

For cylinders without liners which comprise of two parts joined with adhesive, additional procedures and parameters shall be defined, monitored and recorded and are:

a) adhesive system component percentages and batch numbers;

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 an 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, underwater suitability, vacuum suitability and/or maximum fitting torque restrictions) shall be stated

4.4.2 Cylinders without liner

The requirements for the composite materials and their properties to be specified are:

a) tensile strength;

b) tensile modulus;

c) elongation;

d) heat distortion temperature;

e) viscosity

The composite materials shall be compatible with the contained gas as determined by

EN ISO 11114-2 The auto-ignition temperature in oxygen gas shall be determined in accordance with

EN ISO 11114-3 for cylinders intended for air, oxygen and oxidising gases

Where a metal end boss is used in a cylinder without liner, the drawing of the cylinder shall include the specification of the material and material properties of the boss in accordance with 4.2.2.2

4.4.3 Autofrettage

Internal pressurisation 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

4.4.4 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)

5 Cylinder and material tests

5.1 General

This clause describes tests to be conducted on fully wrapped composite 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

5.2 Requirements and test methods

5.2.1 Test 1 – Composite material tests, including adhesives (where applicable)

5.2.1.1 All cylinders

5.2.1.1.1 Procedure

Tests on the composite materials to establish their mechanical properties shall be carried out in

accordance with:

a) fibre tensile properties:

1) for glass, aramid: ISO 8521 or ASTM D 2290-92 and ASTM D 2291-83;

ISO 3341 or ASTM D 2343-03;

2) for carbon: ISO10618 or ASTM D 4018-93;

b) shear properties: ISO 14130 or ASTM D 2344-84;

c) matrix properties: glass transition temperature: ASTM D 3418-99;

heat distortion temperature: ISO 75 -3;

a) tensile strength: ISO 527-1 and ISO 527-2;

b) tensile modulus: ISO 527-1 and ISO 527-2;

c) elongation: ISO 527-1 and ISO 527-2;

d) heat distortion temperature: ISO 3146 for thermoplastics; ISO 75-1 and ISO 75-3 for

Equivalent tests in accordance with alternative standards or test specifications acceptable to the inspection body may be applied

Tests on the liner material shall be carried out for:

a) seamless steel – as described in EN 1964-1, EN 1964-2 or EN ISO 11120, as appropriate; b) seamless stainless steel – as described in EN 1964-3;

c) welded steel – as described in EN 13322-1 or prEN 14638-3, as appropriate;

d) seamless aluminium – as described in EN 1975;

e) welded stainless steel – as described in EN 13322-2 or EN 14638-1;

f) welded aluminium – as described in EN 12862;

g) non-metallic materials:

1) thermoplastics:

i) viscosity – ISO 1628-3:

ii) melting point – ISO 3146;

iii) water content – ISO 15512;

iv) density – ISO 1183;

v) melting flow index – ISO 1133;

vi) chemical resistance – ISO 175;

vii) auto-ignition test – EN ISO 11114-3 (air, oxygen and oxidising gases only)

2) thermosets and elastomerics:

i) viscosity - ISO 2884-1 or ASTM D 2196-86;

ii) elongation at break – ISO 527-1 and ISO 527-2;

iii) tensile strength – ISO 527-1 and ISO 527-2;

iv) density – ISO 1183;

v) chemical resistance – ISO 175;

vi) auto-ignition test – EN ISO 11114-3 (Air, oxygen and oxidising gases only)

Equivalent tests in accordance with alternative standards or test specifications acceptable to the inspection body may be applied

The cylinder shall be pressurised 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

5.2.3.2 Criteria

!

a) Burst pressure of the liner (pbl) shall be equal to or greater than the minimum design burst pressure, as specified in 4.2.3;

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."

5.2.3.3 Parameters to monitor and record

a) Burst pressure;

b) the number of pieces;

c) failure description;

d) pressure/time curve or pressure/volume curve

5.2.4 Test 4 – Pressure test of finished cylinders at ambient temperature

The fluid pressure in the cylinder shall be increased at a controlled rate until the test pressure (ph) is

reached The cylinder shall remain at the test pressure (ph) for at least 30 s

The limit deviation on attaining test pressure shall be + 3 % - 0 % of test pressure (ph)

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

5.2.4.2 Criteria

a) Pressure shall remain steady;

b) there shall be no leaks;

c) after the test, the cylinder shall show no visible permanent deformation

5.2.4.3 Parameters to monitor during the test

The cylinder shall be pressurised 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

c) For cylinders without liners manufactured from two parts joined together, the burst shall not result

in separation at the joint."

5.2.5.3 Parameters to monitor and record

a) Burst pressure;

b) number of pieces;

c) description of failure;

d) pressure/time curve or pressure/volume curve

5.2.6 Test 6 – Resistance to pressure cycles at test pressure (ph ) and ambient temperature 5.2.6.1 For non-limited life

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 hydraulic test pressure (ph) for unspecified gas service or maximum developed pressure at 65 °C, pmax, for the dedicated gas which has the greatest developed pressure The value of the lower cyclic pressure shall not exceed 10 % of the upper cyclic pressure and shall have an absolute 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 0,25 Hz (15 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

5.2.6.1.2 Criteria

The cylinder shall withstand 12 000 cycles up to test pressure (ph) or 24 000 cycles up to maximum

developed pressure (pmax) without failure by burst or leakage

5.2.6.1.3 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

5.2.6.2 For limited life

5.2.6.2.1 Procedure

This test shall be conducted in accordance with the procedure as described in 5.2.6.1 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

5.2.6.2.2 Criteria

The cylinders shall withstand N pressurisation cycles to test pressure (ph) or Nd pressurisation cycles

to maximum developed pressure (pmax) without failure by burst or leakage, where:

N = y x 250 cycles per year of design life;

Nd = y x 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 10 years

The test shall continue for a further N or Nd 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

Number of cycles 0 to N N to 2N but 2N no more than 12 000

0 to Nd Nd to 2Nd but 2Nd no more than 24 000

No leakage or burst Leakage = Pass Pass 1st part Burst = Fail

5.2.6.2.3 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 appropriate

5.2.7 Test 7 – Immersion in salt water

5.2.7.1 General

This test is required for cylinder designs intended for underwater applications and is optional for other applications

5.2.7.2 Procedure

The cylinder shall be finished as for the intended application and without external coating unless this

is an integral part of the design

Two closed cylinders shall be immersed in an aqueous solution containing 35 g/l of sodium chloride at

20 °C ± 5 °C for 90 days continuously

The cylinders shall be immersed:

a) for 45 days at not less than 2/3 × test pressure (ph);

b) for 45 days without pressure

The pressure shall be recorded at least at the beginning of the test and after 45 days, prior to pressurisation

de-Then, following the 90 day immersion:

c) one of the two cylinders shall be subjected to Test 5 (see 5.2.5);

d) the other cylinder shall be subjected to Test 6 (see 5.2.6)

After completion of Test 6, the cylinder shall be destroyed (e.g by bursting) or made incapable of holding pressure

5.2.7.3 Criteria

a) For the first cylinder:

1) burst pressure shall be greater than or equal to the manufacturer's minimum specified design burst pressure and 2 × test pressure (pb≥ 2,0 ph);

2) for cylinders without liners manufactured from two parts joined together, the burst shall not result in separation at the joint

b) For the second cylinder, the criteria shall be as Test 6 (see 5.2.6), appropriate for the design life

5.2.7.4 Parameters to monitor and record

a) Temperature of the solution, at least twice a day;

b) filling pressure;

c) duration of immersion;

d) burst pressure;

e) description of failure;

f) parameters specified in Test 6 (see 5.2.6)

5.2.8 Test 8 - Exposure to elevated temperature at test pressure

5.2.8.1 Procedure

For a design service life of up to 20 years, two cylinders shall be hydraulically pressurised to test

pressure (ph), and shall be maintained at this pressure for 1 000 h

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 less than 50 % After this test, the cylinders shall be subjected to Test 5 (see 5.2.5)

5.2.8.2 Criteria

The burst pressure shall be greater than or equal to 2 × test pressure (pb ≥ 2,0 ph)

5.2.8.3 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

5.2.9 Test 9 - Drop test

5.2.9.1 For cylinders up to and including 80 litres water capacity

Figure 1 — Positions for the impact test

After the full sequence of drops has been completed:

a) one of the two cylinders shall be subjected to Test 5 (see 5.2.5);

b) the other cylinder shall be subjected to Test 6 (see 5.2.6)

After completion of Test 6, the cylinder shall then be destroyed (e.g by bursting) or made incapable of holding pressure

5.2.9.1.2 Criteria

For the first cylinder:

a) burst pressure shall be greater than or equal to the manufacturer's minimum specified design burst pressure and 2 × test pressure (pb≥ 2,0 ph);

For the second cylinder:

b) meet the requirements of 5.2.6

5.2.9.1.3 Parameters to monitor and record

a) visual appearance after each drop - position and dimensions of impact damage;

b) burst pressure;

c) description of failure;

d) parameters specified in 5.2.6

5.2.9.2 For cylinders over 80 litres water capacity

5.2.9.2.1 Procedure

One empty cylinder, fitted with sealing device to protect threads and sealing surfaces, shall be subjected to a sequence of drops from a maximum height of 1,8 m on to a smooth flat concrete surface or as prescribed:

a) horizontally on to the cylinder sidewall;

b) vertically on to the cylinder base (however maximum potential energy of 1 220 Nm shall not be exceeded);

c) vertically on to the other end of the cylinder (however maximum potential energy of 1 220 Nm shall not be exceeded);

d) at an angle of 45° to strike the shoulder of the cylinder (however the drop height shall be such that the centre of gravity of the cylinder is 1,8 m from the floor with the shoulder a minimum of 0,6 m (2 ft) the from floor Where this is not possible, the drop angle should be adjusted to maintain a minimum height of 0,6 m and a centre of gravity of 1,8 m)

The cylinder shall then be subjected to 12 000 pressurisation cycles from zero to 2/3 times test pressure in accordance with the procedure detailed in 5.2.6

5.2.9.2.2 Criteria

The cylinders shall withstand 3 000 pressurisation cycles at the test pressure ph x 2/3 without failure

by burst or leakage The test shall continue for a further 9 000 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

5.2.9.2.3 Parameters to monitor and record

a) Visual appearance after each drop - record position and dimensions of impact damage;

The flaws shall either:

a) for cylinders with metallic liners, be made with a 1 mm thick cutter to a depth equal to at least

50 % of the wound composite thickness and to a length in the bottom of the flaw equal to five times the composite thickness; or

b) for cylinders with non-load sharing liners or without liners, be made with a 1 mm thick cutter to a depth equal to at least 40 % of the wound composite thickness and to a length in the bottom of the flaw equal to five times the composite thickness

Key

1 1 mm wide

2 wrap

3 liner

Figure 2 — Flaw detail

After introducing the flaws, one of the two cylinders shall be subjected to Test 5 (see 5.2.5) The other cylinder shall be subjected to Test 6 (see 5.2.6) except that the upper cyclic pressure shall be 2/3 × ph

and the number of cycles shall be a maximum of 5 000

After completion of Test 6, the cylinder shall be destroyed (e.g by bursting) or made incapable of holding pressure

5.2.10.3 Parameters to monitor and record

a) Burst pressure;

b) number of cycles;

c) flaw size;