EN 13322-1:2003

SLOVENSKI STANDARD
01-december-2003
3UHPLþQHSOLQVNHMHNOHQNH3RQRYQRSROQOMLYHMHNOHQNH1DþUWRYDQMHLQL]GHODYD
GHO-HNOHQNHL]RJOMLþQHJDMHNOD
Transportable gas cylinders - Refillable welded steel gas cylinders - Design and
construction - Part 1: Carbon steel
Ortsbewegliche Gasflaschen - Wiederbefüllbare geschweißte Flaschen aus Stahl -
Gestaltung und Konstruktion - Teil 1: Flaschen aus Kohlenstoffstahl
Bouteilles a gaz transportables - Bouteilles a gaz rechargeables soudées en acier -
Conception et construction - Partie 1: Acier au carbone
Ta slovenski standard je istoveten z: EN 13322-1:2003
ICS:
23.020.30 7ODþQHSRVRGHSOLQVNH Pressure vessels, gas
MHNOHQNH cylinders
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 13322-1
NORME EUROPÉENNE
EUROPÄISCHE NORM
March 2003
ICS 23.020.30
English version
Transportable gas cylinders - Refillable welded steel gas
cylinders - Design and construction - Part 1: Carbon steel
Bouteilles à gaz transportables - Bouteilles à gaz Ortsbewegliche Gasflaschen - Wiederbefüllbare
rechargeables soudées en acier - Conception et geschweißte Flaschen aus Stahl - Gestaltung und
construction - Partie 1: Acier au carbone Konstruktion - Teil 1: Flaschen aus Kohlenstoffstahl
This European Standard was approved by CEN on 28 November 2002.
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 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 Management Centre has the same status as the official
versions.
CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece,
Hungary, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Slovak Republic, Spain, Sweden, Switzerland and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2003 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 13322-1:2003 E
worldwide for CEN national Members.

Contents
page
Foreword.3
Introduction .4
1 Scope .5
2 Normative references .5
3 Terms, definitions and symbols.6
4 Materials and heat treatment .8
5 Design .8
6 Construction and workmanship.12
7 New design tests.15
8 Batch tests.17
9 Tests on every cylinder .25
10 Failure to meet test requirements .25
11 Records.26
12 Marking .26
Annex A (normative)  Cylinders made from longitudinal seam high frequency induction (HFI) welded
tube by spinning of the end.27
Annex B (normative)  Radiographic examination of welds .29
Annex C (normative)  Description, evaluation of manufacturing defects and conditions for rejection of
welded steel gas cylinders at time of visual inspection .32
Annex D (informative)  Examples of design and batch test certificates.35
Annex E (informative)  Guidance on the application of conformity assessment modules when using
this standard.42
Bibliography .47
Foreword
This document (EN 13322-1:2003) 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 September 2003, and conflicting national standards shall be withdrawn at the
latest by September 2003.
This European Standard has been submitted for reference into the RID and/or in the technical annexes of the ADR.
Therefore in this context the standards listed in the normative references and covering basic requirements of the
RID/ADR not addressed within the present standard are normative only when the standards themselves are
referred to in the RID and/or in the technical annexes of the ADR.
For relationships with EC directives, RID and ADR see informative annex E, which is an integral part of this
document.
This standard is one of a series of two standards concerning refillable welded steel gas cylinders of water
capacities from 0,5 l up to and including 150 l for compressed, liquefied and dissolved gases:
Part 1: Carbon steel
Part 2: Stainless steel
Annexes A, B and C are normative. Annexes D and E are informative.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal,
Slovak Republic, Spain, Sweden, Switzerland and the United Kingdom.
Introduction
The purpose of this European Standard is to provide a specification for the design, manufacture, and testing of
refillable, transportable, welded steel gas cylinders.
The specifications given are based on knowledge of, and experience with, materials, design requirements,
manufacturing processes and control during manufacture, of cylinders in common use in the countries of the CEN
members.
This standard is based on the traditional calculation method. It does not cover other methods such as finite element
analysis (F.E.A) methods or experimental methods.
1 Scope
This European Standard specifies minimum requirements concerning material, design, construction and
workmanship, manufacturing processes and testing of refillable transportable welded carbon steel gas cylinders of
water capacities from 0,5 l up to and including 150 l for compressed, liquefied and dissolved gases.
For acetylene service, additional requirements for the cylinder and the basic requirements for the porous mass are
given in EN 1800. For those cylinders made from high frequency induction (HFI) welded steel tubes, the
requirements are given in annex A.
This standard is primarily for industrial gases other than LPG but may also be applied for LPG. However for
dedicated LPG cylinders, see EN 1442, Transportable refillable welded steel cylinders for liquefied petroleum gas
(LPG) - Design and construction prepared by CEN/TC 286 Liquefied petroleum gas equipment and accessories.
2 Normative references
This European Standard incorporates by dated or undated reference, provisions from other publications. These
normative references are cited at the appropriate places in the text, and publications are listed hereafter. For dated
references, subsequent amendments to or revisions of any of these publications apply to this European Standard
only when incorporated in it by amendment or revision. For undated references the latest edition of the publication
referred to applies (including amendments).
EN 287-1, Approval testing of welders - Fusion welding - Part 1: Steels.
EN 288-1, Specification and qualification of welding procedures for metallic materials - Part 1: General rules for
fusion welding.
EN 288-3, Specification and approval of welding procedures for metallic materials - Part 3: Welding procedure tests
for the arc welding of steels.
EN 473, Non destructive testing - Qualification and certification of NDT personnel - General principles.
EN 962, Transportable gas cylinders - Valve protection caps and valve guards for industrial and medical gas
cylinders - Design, construction and tests.
EN 970, Non-destructive examination of fusion welds - Visual examination.
EN 1089-1, Transportable gas cylinders - Gas cylinder identification (excluding LPG) - Part 1: Stampmarking.
EN 1435, Non-destructive examination of welds - Radiographic examination of welded joints.
EN 1442, Transportable refillable welded steel cylinders for liquefied petroleum gas (LPG) - Design and
construction.
EN 1964-1:1999, 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 value of less than 1100 MPa.
m
EN 10002-1, Metallic materials - Tensile testing - Part 1: Method of test at ambient temperature.
EN 10028-1, Flat products made of steels for pressure purposes - Part 1: General requirements.
EN 10028-3, Flat products made of steels for pressure purposes - Part 3: Weldable fine grain steels, normalized.
EN 10028-5, Flat products made of steels for pressure purposes - Part 5: Weldable fine grain steels,
thermomechanically rolled.
EN 10045-1, Metallic materials - Charpy impact test - Part 1: Test method.
EN 10083-1 + A1, Quenched and tempered steels - Part 1: Technical delivery conditions for special steels
(includes amendment A1:1996)
EN 10120, Steel sheet and strip for welded gas cylinders.
EN 10208-2, Steel pipes for pipelines for combustible fluids - Technical delivery conditions - Part 2: Pipes of
requirement class B.
EN 12517, Non-destructive examination of welds - Radiographic examination of welded joints - Acceptance levels.
EN 13445-2, Unfired pressure vessels - Part 2: Materials.
EN 25817, Arc-welded joints in steel - Guidance on quality levels for imperfections (ISO 5817:1992).
EN ISO 11114-1, Transportable gas cylinders - Compatibility of cylinder and valve materials with gas contents -
Part 1: Metallic materials (ISO 11114-1:1997).
ISO 2504:1973, Radiography of welds and vewing conditions for films - Utilization of recommended patterns of
image quality indicators (I.Q.I.).
3 Terms, definitions and symbols
For the purpose of this standard, the following terms, definitions and symbols apply.
3.1 Terms and definitions
3.1.1
yield stress
value corresponding to the lower yield stress, R , or 0,92 · the upper yield stress (R ) or for steels that do not
eL eH
exhibit a defined yield, the 0,2 % proof stress (R )
p0,2
[EN 10002-1]
3.1.2
normalizing
heat treatment in which a cylinder is heated to a uniform temperature above the upper critical point (AC , as
defined in EN 10052) of the steel and then cooled in a controlled atmosphere
3.1.3
stress relieving
heat treatment given to the finished cylinder, the object of which is to reduce the residual stresses without altering
the metallurgical structure of the steel, by heating to a uniform temperature below the lower critical point (AC , as
defined in EN 10052) of the steel and cooling in a still atmosphere
3.1.4
batch
quantity of finished cylinders made consecutively during the same or consecutive days to the same design, size
and material specifications and from the same material supplier for each pressure containing part on the same
automatic welding machines and heat-treated under the same conditions of temperature and duration
NOTE This definition allows different suppliers to be used for the different pressure containing parts within a batch, e.g.
one supplier for heads, another for bases.
3.1.5
design stress factor (F)
ratio of equivalent wall stress at test pressure (p ) to guaranteed minimum yield stress (R )
h e
3.2 Symbols
a Calculated minimum thickness, in millimetres, of the cylindrical shell
a' Guaranteed minimum thickness, in millimetres, of the cylindrical shell (including any corrosion allowance see
7.1)
a Calculated value of a used in the calculation of b (see 5.3.2)
A Percentage elongation after fracture
b Calculated minimum thickness, in millimetres, of the cylinder end (see Figure 1)
b' Guaranteed minimum thickness, in millimetres, of the cylinder end (see 7.1 )
C Shape factor of dished ends
D Outside diameter, in millimetres, of the cylinder (see Figure 1)
D Diameter of former in millimetres (see Figure 11)
f
F Design stress factor (see 3.1.5)
h Height, in millimetres, of the cylindrical part of the end (see Figure 1)
H Outside height, in millimetres, of the domed part of the end (see Figure 1)
J Stress reduction factor (see annex B)
L Length, in millimetres, of the cylinder
n Ratio of diameter of bend test former (D ) to the thickness of the test piece (t)
f
p Measured burst pressure, in bar , above atmospheric pressure, in the burst test
b
1)
p Hydraulic test pressure, in bar , above atmospheric pressure
h
r Inside radius of knuckle end, in millimetres (see Figure 1)
R Inside radius of the dished end, in millimetres (see Figure 1)
R Yield stress, in megapascals, as defined in 3.1.1 and used for design calculation
e
R Value of the actual yield stress in megapascals determined by the tensile test
ea
R Minimum value of the upper yield stress, in megapascals, guaranteed by the cylinder manufacturer for the
eH
finished cylinder, in accordance with EN 10002-1
R Minimum value of the lower yield stress, in megapascals, guaranteed by the cylinder manufacturer for the
eL
finished cylinder, in accordance with EN 10002-1
R Minimum value of tensile strength, in megapascals, guaranteed by the cylinder manufacturer for the finished
g
cylinder
R Actual value of tensile strength, in megapascals, determined by the tensile test (see 8.4)
m
1 1 bar = 10 Pa = 0,1 MPa
S Original cross-sectional area of tensile test piece, in square millimetres, according to EN 10002-1
o
t Actual thickness of the test specimen, in millimetres (see Figure 7)
4 Materials and heat treatment
4.1 General
4.1.1 Materials supplied for shells and end pressing shall conform to EN 10120, or EN 10028-1 and EN 10028-3,
or EN 10028-1 and EN 10028-5.
4.1.2 Materials supplied for bungs shall conform to EN 10083-1 + A1.
4.1.3 Grades of steel used for the manufacture shall be compatible with the intended gas service (e.g. corrosive
gases, embrittling gases) in accordance with EN ISO 11114-1.
4.1.4 All parts welded to the cylinder shall be made of compatible material with respect to the weldability.
4.1.5 The welding consumables shall be such that they are capable of giving consistent welds with minimum
tensile strength at least equal to that specified for the parent material in the finished cylinder.
4.1.6 The manufacturer shall obtain and provide certificates of the ladle analysis of the steel supplied for the
construction of the pressure retaining parts of the cylinder.
4.1.7 The manufacturer shall be able to guarantee cylinder steel casting traceability for each cylinder.
4.1.8 Cylinders for acetylene service shall be manufactured with materials compatible with the manufacturing
process of the porous mass, or an internal coating shall be applied.
4.2 Heat treatment
Cylinders shall be delivered in either the normalised or the stress-relieved condition. The cylinder manufacturer
shall certify that the cylinders have been heat-treated after completion of all welding and shall certify the process of
heat treatment applied. Localised heat treatment of cylinders is not permitted, nor in the case of repaired cylinders.
The actual temperature of heat treatment to which a type of steel is subjected for a given tensile strength shall not
deviate by more than 30 °C from the temperature specified by the manufacturer for the cylinder type.
5 Design
5.1 General requirements
5.1.1 The calculation of the wall thickness of the pressure parts shall be related to the yield stress of the parent
material.
5.1.2 For calculation purposes, the value of the yield stress R is limited to a maximum of 0,85 R .
e g
5.1.3 The internal pressure upon which the calculation of gas cylinders is based shall be the test pressure p .
h
5.1.4 A fully dimensioned drawing including the specification of the material shall be produced.
5.1.5 Cylinders for acetylene service shall be designed to allow for a test pressure of at least 60 bar.
5.1.6 Cylinders for acetylene service shall be designed and manufactured to ensure that conditions are safe for
the eventual filling of the porous mass, e.g. preventing sharp edges and voids.
5.2 Calculation of cylindrical wall thickness
The wall thickness of the cylindrical shell shall be not less than that calculated using the formula
 
D 10.F.J.R-3.p
 
e h
a = ⋅ 1-
 
2 10.F.J.R
 
e
Łł
0,65
where the value of F is the lesser of or 0,77.
(Re/Rg )
R /R shall not exceed 0,85.
e g
The value of J shall be selected in accordance with annex B.
The minimum wall thickness shall also satisfy the requirements of 5.4.
5.3 Design of convex ends (see Figure 1)
5.3.1 The shape of ends of gas cylinders shall be such that the following conditions are fulfilled:
 for torispherical ends (see Figure 1a): R £ D;
r ‡ 0,1 D;
h ‡ 4b.
 for ellipsoidal ends (see Figure 1b): H ‡ 0,192 D;
h ‡ 4b.
5.3.2 The wall thickness of the ends of gas cylinders shall be not less than that calculated using the formula:
b = a · C
where
a is the value of a calculated in accordance with 5.2 using J = 1,0;
C is a shape factor, whose value shall be obtained from the graphs given in Figures 2 and 3.
a) Torispherical b) Ellipsoidal
Figure 1 — Illustration of cylinder ends
Figure 2 — Values of shape factor C for H/D between 0,2 and 0,25
Figure 3 — Values of shape factor C for H/D between 0,25 and 0,5
5.4 Minimum wall thickness
5.4.1 The minimum wall thickness of the cylindrical shell a and end b shall be not less than the value derived
from the appropriate one of the following formulae:
for D £ 100 mm, a = b = 1,1 mm;
for 100 mm < D £ 150 mm, a = b = 1,1 + 0,008(D - 100) mm;
D
for D > 150 mm, a = b = + 0,7 mm, with an absolute minimum of 1,5 mm.
These formulae apply to cylindrical shells and ends irrespective of whether they are designed by calculation under
5.2 and 5.3 or by the pressure cycling test in 7.3.2.
5.4.2 Apart from the requirements of 5.3, 5.4 and 5.5 any cylindrical part integral with an end shall, except as
qualified by 5.4.3, also satisfy the requirements given in 5.2 for the cylindrical shell.
5.4.3 Where the length of the cylindrical portion of the gas cylinder, measured between the beginning of the
domed parts of the two ends, is not more than 2bD , the wall thickness shall be not less than that of the domed
part (see 5.3.2).
NOTE For certain gases, additional corrosion allowance can be applicable.
5.5 Ends of other shapes
Ends of shapes other than those covered by 5.3 may be used provided that the adequacy of their design is
demonstrated by a pressure cycling test in accordance with 7.3.2 or by stress analysis.
5.6 Design of openings
5.6.1 The location of all openings shall be restricted to the end(s) of cylinders.
5.6.2 Each opening in the cylinder shall be reinforced, either by a valve boss or pad, of weldable and compatible
steel, securely attached by welding and so designed as to be of adequate strength and to result in no harmful
stress concentrations. This shall be confirmed by design calculations or a pressure cycling test in accordance with
7.3.2.
5.6.3 The welds of the openings shall be separated from longitudinal and circumferential joints by a distance not
less than 3a.
6 Construction and workmanship
6.1 General
The cylinder or cylinder parts shall be produced by:
 using seamless or longitudinally welded tube with forged ends being circumferentially welded; or
 using longitudinally welded tube with spun ends; or
 using a seamless tube, followed by hot forming where the base is sealed with added weld metal; or
 using cold worked tube or plates; or
 using deep drawn parts; or
 using high frequency induction welded tube with welded ends.
6.2 Welding procedures
Each manufacturer, before proceeding with the production of a given design of cylinder, shall qualify all welding
procedures to EN 288-1 and EN 288-3 and welders to EN 287-1. Records of such qualification shall be kept on file
by the manufacturer.
6.3 Welded joints of pressure containing parts
6.3.1 The welding of longitudinal and circumferential seams shall be by an automatic process. Manual welding is
however permitted for boss welds except when they are butt welds.
6.3.2 The longitudinal joint, of which there shall be no more than one, shall be butt-welded.
6.3.3 Circumferential joints, of which there shall be no more than two, excluding end bungs, shall be butt-welded,
joggle welded, or butt welded with a backing ring.
6.3.4 For acetylene service, the joints shall be designed in such a way as to eliminate the risk of damaging the
porous mass.
6.4 Non-pressure-containing attachments
6.4.1 Parts which are not submitted to pressure such as footrings, handles and neckrings shall be made of steel
compatible with that of the cylinder.
Each attachment shall be designed to permit inspection of the attachment welds, shall be clear of
6.4.2
longitudinal and circumferential joints, and so designed as to avoid trapping water.
6.4.3 A footring or other support shall be fitted to the cylinder when required to provide stability, and attached so
as to permit inspection of the bottom circumferential weld. Permanently attached footrings shall be drained and the
space enclosed by the footring shall be ventilated.
6.5 Valve protection
6.5.1 Valves of cylinders of more than 5 l water capacity shall be protected from damage which could cause
release of gas, either by the design of the cylinder (e.g. protective shroud) or by a valve protection device (in
accordance with EN 962).
6.5.2 When a protective shroud is used, it shall fulfil the requirements of the drop test described in EN 962.
6.5.3 The requirements of 6.5.1 and 6.5.2 may be waived when the cylinders are intended to be conveyed in
bundles or cradles, or when some other effective valve protection is provided.
6.6 Neck threads
The internal neck threads shall conform to a recognized standard to permit the use of a corresponding valve thus
minimizing neck stresses following the valve torquing operation. Internal neck threads shall be checked using
gauges corresponding to the agreed neck thread, or by an alternative method. Particular care shall be taken to
ensure that neck threads are accurately cut, are of full form and free from any sharp profiles, e.g. burrs.
NOTE For example, where the neck thread is specified to be in accordance with EN 629-1, the corresponding gauges are
specified in EN 629-2.
6.7 Visual examination
6.7.1 Unacceptable defects
Before assembly, the pressure containing parts of the cylinders shall be examined for uniform quality and freedom
from unacceptable defects, examples of which are given in annex C.
6.7.2 Welds
6.7.2.1 Before the cylinders are closed, longitudinal welds shall be visually examined from both sides.
Permanent backing strips shall not be used with longitudinal welds.
6.7.2.2 All welds shall have a smooth finish without concavity and shall merge into the parent material without
under-cutting or abrupt irregularity.
6.7.2.3 Butt welds shall have full penetration. For joggle welds, the penetration shall be full on the straight
edge and shall be sufficient on the swaged edge (see Figure 4).
6.7.2.4 Radiographic examination, radioscopic examination, or NDT examination carried out using another
suitable method, shall be as specified in annex B.
Dimensions in millimetres
Butt Welds Joggle welds
Figure 4 — Illustration of welding penetration
6.7.3 Out of roundness
The out-of-roundness of the cylindrical shell shall be limited so that the difference between the maximum and the
minimum outside diameter in the same cross-section is not more than 2 % of the mean of these diameters.
6.7.4 Straightness
Unless otherwise specified on the manufacturing drawing, the maximum deviation of the cylindrical part of the shell
from a straight line shall not exceed 0,3 % of the cylindrical length.
6.7.5 Verticality
When the cylinder is standing on its base, the cylindrical shell and concentric top opening shall be vertical to within
1 % of the cylindrical length.
6.7.6 Tightness
Tests appropriate to the manufacturing process shall be carried out to ensure that there is no leakage from the
cylinder.
7 New design tests
7.1 General requirements
7.1.1 Testing shall be carried out for each new design of cylinder.
A cylinder shall be considered to be of a new design compared with an existing design when:
 it is manufactured in a different factory; or
 it is manufactured by a different welding process or a radical change in an existing process, e.g. change of
type of heat treatment; or
 it is manufactured from a steel of different specified chemical composition range; or
 it is given a different heat treatment outside the ranges stipulated in 4.2; or
 if there is a change in base profile, e.g. concave, convex, hemispherical, or there is a change in the base
thickness/cylinder diameter ratio; or
 the guaranteed minimum yield stress (R ) or guaranteed minimum tensile strength (R ) has changed; or
e g
 the overall length of the cylinder has increased by more than 50 % (cylinders with a length/diameter ratio less
than 3 shall not be used as reference cylinders for any new design with this ratio greater than 3); or
 the nominal outside diameter has changed; or
 the guaranteed minimum wall thickness (a') or the guaranteed minimum end thickness (b') has been
decreased; or
 the hydraulic test pressure has been changed (where a cylinder is used for a lower pressure duty than that for
which the cylinder was approved, it shall not be deemed a new design).
7.1.2 A technical specification of the cylinder, including design drawing, design calculations, material details,
welding and manufacturing process and heat treatment, shall be prepared by the manufacturer and attached to the
design test certificate (see annex D).
7.1.3 A minimum of 50 finished cylinders, which shall be guaranteed by the manufacturer to be representative of
a new design, shall be made available for design testing. If the total production is less than 50 cylinders, enough
cylinders shall be made to complete the tests required, in addition to the production quantity. In this case the
design test certificate is limited to the particular batch.
7.1.4 The testing process shall include the verifications and tests listed in 7.2.1 and 7.2.2 respectively.
7.2 Verifications and tests
7.2.1 Verifications
It shall be verified that:
 the requirements of clause 4 (material) are fulfilled;
 the design conforms to the requirements of clause 5;
 the requirements of clause 6 and annex B are fulfilled for all cylinders selected;
 the internal and external surfaces of the cylinders are free of any defect which may make them unsafe for use
(see annex C).
7.2.2 List of tests
The following shall be performed on cylinders selected after the welds of the cylinders have been visually
inspected:
 the test specified in 7.3.1 (hydraulic burst test) on one cylinder, the cylinder bearing representative
stampmarking;
— the test specified in 7.3.2 (pressure cycling test) on one cylinder, the cylinder bearing representative
stampmarking.
 the tests specified in 8.4 (tensile test), 8.5 (bend test), 8.6 (impact test) where applicable and 8.7 (macroscopic
examination of weld cross-sections), on one cylinder, the test pieces being identifiable to the batch;
 radiographic examination, radioscopic examination, or NDT examination carried out using another suitable
method, as specified in annex B;
7.3 Descriptions of tests
7.3.1 Hydraulic burst test
7.3.1.1 Cylinders subjected to this test shall bear markings in accordance with the complete stamp markings
as required for the finished cylinder. The hydraulic burst test shall be carried out with equipment which enables the
pressure to be increased at a controlled rate until the cylinder bursts and the change in pressure with time to be
recorded.
7.3.1.2 For a test pressure (p ) £ 60 bar the burst pressure (p ) shall be at least 9/4 times the test pressure
h b
with a minimum burst pressure of 50 bar, and for a test pressure > 60 bar the burst pressure shall be at least twice
the test pressure.
7.3.1.3 The burst test shall not cause any fragmentation of the cylinder.
7.3.1.4 The main fracture shall not show any brittleness, i.e. the edges of the fracture shall not be radial but
shall be at an angle to a diametral plane and display a reduction of area throughout their thickness. The fracture
shall be examined and shall be free of defects.
7.3.1.5 Additionally for cylinders with a test pressure (p ) £ 60 bar, the ratio of the volumetric expansion of the
h
cylinder to its initial volume shall be at least:
 20 % if the length of the cylinder is greater than the diameter; or
 17 % if the length of the cylinder is equal to or less than the diameter.
7.3.2 Pressure cycling test
7.3.2.1 The pressure cycling test shall be carried out on one cylinder bearing the required stamp markings.
See clause 12 for particular requirements concerning stamp markings on the dome ends.
7.3.2.2 This test shall be carried out with a non-corrosive liquid, subjecting the cylinder to successive reversals
at an upper cyclic pressure which is equal to the hydraulic test pressure (p ). The value of the lower cyclic pressure
h
shall not exceed 10 % of the upper cyclic pressure. The frequency of reversals of pressure shall not exceed
0,25 Hz (15 cycles/minute). The temperature measured on the outside surface of the cylinder shall not exceed
50 °C during the test.
7.3.2.3 The cylinder shall be subjected to 12 000 cycles without leakage or failure.
7.3.2.4 For cylinders manufactured according to annex A or manufactured from tubes with spun ends, after the
test the cylinder bases shall be sectioned in order to measure the thickness and to ensure that this thickness is no
more than 15 % above the minimum base thickness prescribed in the design. The actual wall and base thickness
shall be measured and recorded on the design test certificate.
7.4 Design testing certificate
If the results of the checks are satisfactory, a design test certificate shall be issued, a typical example of which is
given in annex D.
8 Batch tests
8.1 General
For the purpose of carrying out the batch testing, a random sample of cylinders as indicated in Table 1 shall be
taken from each batch, as defined in 3.1.4. A batch shall consist of a maximum of 3 000 cylinders. All batch tests
shall be carried out on finished cylinders.
Table 1 — Batch sampling
Batch size Number of cylinders to be tested
Number Tensile Impact test Macroscopic Burst tests
of test and (as per 8.6) examination (as per 7.3.1)
cylinders bend test (as per 8.7)
taken as (as per 8.4
samples and 8.5)
Up to 200 2 1 1 1 1
201 to 500 3 1 1 1 2
501 to 1 500 9 2 1 1 7
1 501 to 3 000 18 3 1 1 15
If required, as defined in 7.3
8.2 Information
For the purpose of batch testing, the manufacturer shall provide the following:
 the design test certificate;
 the certificates for the material of construction as required in 4.1.6 stating the cast analyses of the steel
supplied for the construction of the cylinders;
 a list of cylinders, stating serial numbers and stamp markings as required;
 a statement of the thread checking method used and the results thereof.
8.3 Checks and verifications
The following checks and verifications shall be carried out on each batch of cylinders:
 ascertain that a design test certificate has been obtained and that the cylinders conform to it;
 check whether the requirements set out in clauses 4, 5, 6 and 12 have been met, and in particular check
by an external and internal examination of the cylinders whether the construction and checks carried out
by the manufacturer in accordance with clause 6 are satisfactory. The visual examination shall cover at
least 10 % of the cylinders submitted. However, if an unacceptable defect is found (as described in
annex C) 100 % of cylinders shall be visually inspected;
 carry out or witness the tests specified in 8.4 (tensile test), 8.5 (bend test), 8.6 (impact test) where
applicable, 8.7 (macroscopic examination of weld cross-sections) and 7.3.1 (hydraulic burst test) on the
number of cylinders specified in 8.1;
 check whether the information supplied by the manufacturer listed in 8.2 is correct; random checks shall
be carried out;
 assess the results of the NDT examination, as specified in annex B.
8.4 Tensile test
8.4.1 General
The tensile test on parent metal shall be carried out on a test sample taken from the finished cylinder in accordance
with the requirements of EN 10002-1. The two faces of the test sample formed by the inside and the outside
surfaces of the cylinder shall not be machined. The tensile test on welds shall be carried out in accordance with
8.4.3.
8.4.2 Tensile test samples required from parent material
8.4.2.1 For two-part cylinders, either one tensile test sample shall be cut in the longitudinal direction from the
cylindrical portion of one end of the cylinder, or, if there is not sufficient cylindrical length available to permit cutting
the cylindrical portion, then one tensile test sample shall be taken from one end (see Figure 6).
8.4.2.2 For three-part cylinders, one tensile test sample in the longitudinal direction from the shell section
180° away from the weld and one tensile test sample from either of the ends shall be taken. If the two ends are of
different grades or from a different supplier of material, a tensile test sample shall be taken from each end (see
Figure 5).
8.4.2.3 The values obtained for yield stress (R ), tensile strength (R ) and elongation (A) shall be not less
ea m
than those guaranteed by the cylinder manufacturer and in accordance with those given in EN 10120, or
EN 10028-1 and EN 10028-3, or EN 10028-1 and EN 10028-5, as appropriate.
8.4.3 Tensile test samples required from welds
8.4.3.1 For two-part cylinders, one tensile test sample shall be taken (see Figure 5).
8.4.3.2 For three-part cylinders, one tensile test sample on the longitudinal weld shall be taken. If the
circumferential welds are made by a different procedure, then the same test shall also be made on this weld (see
Figure 6).
8.4.3.3 The tensile test transverse to the weld shall be carried out on a test sample having a reduced section
25 mm wide over a length extending to 15 mm beyond each edge of the weld. Outside this central part, the width of
the test sample shall increase progressively (see Figure 7).
8.4.3.4 All tensile tests shall be in a direction transverse to the weld. The face and root of the weld in the test
sample shall be machined flush to the plate surface.
The face and back of the parent metal shall not be machined but shall represent the surface of the cylinder as
manufactured. The ends only may be flattened, by cold pressing, for gripping in the test machine. The tensile
strength value obtained shall be at least equal to the minimum value specified in 8.4.2.3 for the parent metal,
regardless of the position of the fracture.
Key
1 1 tensile test piece
2 1 tensile test piece, 1 root bend test piece, 1 face bend test piece
3 1 tensile test piece
Required only if insufficient cylindrical length available
4 Impact test
Figure 5 — Test pieces from two-part cylinders
Key
1 1 tensile test piece
2 1 tensile test piece
1 root bend test piece
1 face bend test piece
3 1 tensile test piece
1 root bend test piece
1 face bend test piece
Required only if welded by a different process from longitudinal weld (see 8.4.3.2 and 8.5.5)
4 Impact test piece
5 1 tensile test piece
Figure 6 — Test pieces from three-part cylinders
Dimensions in millimetres
Key
1Weld
Figure 7 — Dimensions of test samples
8.5 Bend test
8.5.1 The specimens for the bend test shall be taken in accordance with Figure 5 or Figure 6 with dimensions as
shown in Figures 8.
8.5.2 The test piece shall not crack when bent inwards around a former until the inside edges are not further
apart than the diameter of the former (see Figure 11).
8.5.3 The ratio n between the diameter (D) of the former and the thickness (t) of the test sample shall be as
f
shown in Table 2.
Table 2 — Bend test requirements
Actual tensile strength R in MPa Value of n
m
R £ 440
m
440 < R £ 520
m
R > 520
m
8.5.4 For two part cylinders, bend test samples shall be taken from the root weld and one face weld, on the
circumferential weld (see Figure 5).
8.5.5 For three part cylinders, one root weld and one face weld shall be taken from the longitudinal weld. If the
circumferential weld is welded by a different procedure, then the same bend tests shall also be carried out on this
weld (see Figure 6).
Dimensions in millimetres
Figure 8 — Transverse guided bend test — Specimen preparation details
Key
1 Weld dressed flush
Figure 9 — Transverse guided bend test — Butt weld specimen
Key
1 Weld dressed flush
Figure 10 — Transverse guided bend test — Joggle joint weld specimen
Figure 11 — Illustration of bend test
8.6 Impact test
8.6.1 The impact test is not required for cylinders where the test pressure is less than or equal to 60 bar and also
the wall thickness is less than 5 mm.
8.6.2 Except for the requirements set out below, the impact test shall be carried out in accordance with
EN 10045-1.
8.6.3 The test temperature shall be at least that specified in EN 13445-2, with a minimum design reference
temperature of – 50 °C. For deciding the test temperature, the actual cylinder wall thickness shall be used.
8.6.4 The following impact test samples shall be taken (see Figure 5 or 6 as appropriate):
 three impact test samples from each parent material;
 three impact tests samples from the longitudinal welds;
 three impact tests samples from one of the circumferential welds.
8.6.5 For the parent material samples, the transverse impact test pieces shall be taken from the wall of the
cylinder. The notch shall be perpendicular to the face of the wall. The test pieces shall be machined on four faces
only, with the inner and outer face of the cylinder wall shall be unmachined. For outside diameters equal or less
than 140 mm, longitudinal impact tests may be performed instead of transverse tests.
8.6.6 For the welds, impact test pieces transverse to the weld shall be taken, except that with cylinders having
outside diameters
 mm, longitudinal test pieces may be taken. The notch shall be in the centre of the weld and
shall be perpendicular to the face of the cylinder. The test pieces shall be machined on all six faces. If the wall
thickness does not permit a final test piece width of 10 mm, the width shall be as near as practicable to the nominal
thickness of the cylinder wall.
8.6.7 The average of three specimens shall meet the value specified in Table 3. No specimen shall show a value
less than 70 % of the average value.
Table 3 — Minimum value for impact test pieces
Tensile strength R > 750 MPa£ 750 MPa
g
Material Parent Weld Parent Weld
Impact energy, (J/cm ) for 20 20 35 35
d > 140 mm. Transverse test
Impact energy (J/cm ) for 16 16 28 28
d £ 140 mm. Longitudinal test
8.7 Macroscopic examination of weld cross-sections
A macroscopic weld examination for each type of welding procedure shall be performed. It shall show complete
fusion and shall be free of any assembly faults or unacceptable defects, as defined in B.3.3.
9 Tests on every cylinder
9.1 Pressure test
All cylinders in each batch shall be subjected to a pressure test. When carrying out a pressure test a suitable fluid,
normally water shall be used as the test medium. The pressure in the cylinder shall be increased at a controlled
rate until the pressure (p ) is reached. The cylinder shall remain under pressure p for at least 30 s to establish that
h h
the pressure does not fall and that there are no leaks.
NOTE A pneumatic pressure test can be substitut
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