Transportable gas cylinders - Reffilable welded steel gas cylinders - Design and construction - Part 2: Stainless steel

This European Standard gives minimum requirements for certain aspects concerning material, design, construction and workmanship, procedure and test at manufacture of refillable welded stainless steel gas cylinders of water capacities from 0,5 l up to and including 150 l for compressed and liquefied gases. This standard is only applicable to cylinders with a maximum tensile strength of less than 1100 MPa.

Ortsbewegliche Gasflaschen - Wiederbefüllbare geschweißte Flaschen aus Stahl - Gestaltung und Konstruktion - Teil 2: Flaschen aus nichtrostendem Stahl

Die vorliegende Europäische Norm legt Mindestanforderungen an Werkstoffe, Konstruktion und fachgerechte Ausführungsweise, Herstellungsverfahren und Prüfung ortsbeweglicher, wiederbefüllbarer, geschweißter Gasflaschen aus nichtrostendem Stahl mit einem Fassungsraum von 0,5 l bis einschließlich 150 l für verdichtete und verflüssigte Gase fest. Diese Norm gilt nur für Flaschen mit einer maximalen Zugfestigkeit bis zu 1100 MPa.

Bouteilles à gaz transportables - Bouteilles à gaz rechargeables soudées en acier - Conception et construction - Partie 2: Acier inoxydable

La présente Norme européenne spécifie les exigences minimales concernant les matériaux, la conception, la construction et l'exécution, ainsi que les procédés de fabrication et les essais des bouteilles à gaz transportables et rechargeables en acier inoxydable soudées ayant une capacité en eau comprise entre 0,5 l et 150 l inclus, destinées à transporter des gaz comprimés, liquéfiés et dissous. Cette norme n'est applicable qu'aux bouteilles fabriquées à partir d'aciers inoxydables ayant une résistance à la traction maximale inférieure à 1 100 MPa.
Les bouteilles destinées à recevoir de l'acétylène sont soumises à des exigences supplémentaires et les exigences de base concernant les masses poreuses sont indiquées dans la norme EN 1800.
La présente norme est principalement destinée aux gaz industriels autres que le GPL, mais peut également être appliquée au GPL.

Premične plinske jeklenke - Ponovno polnljive jeklenke - Načrtovanje in izdelava - 2. del: Jeklenke iz nerjavnega jekla

General Information

Status
Published
Publication Date
04-Mar-2003
Current Stage
9093 - Decision to confirm - Review Enquiry

RELATIONS

Buy Standard

Standard
EN 13322-2:2003
English language
48 pages
sale 10% off
Preview
sale 10% off
Preview
e-Library read for
1 day

Standards Content (sample)

SLOVENSKI STANDARD
SIST EN 13322-2:2003
01-december-2003

3UHPLþQHSOLQVNHMHNOHQNH3RQRYQRSROQOMLYHMHNOHQNH1DþUWRYDQMHLQL]GHODYD

GHO-HNOHQNHL]QHUMDYQHJDMHNOD
Transportable gas cylinders - Reffilable welded steel gas cylinders - Design and
construction - Part 2: Stainless steel
Ortsbewegliche Gasflaschen - Wiederbefüllbare geschweißte Flaschen aus Stahl -
Gestaltung und Konstruktion - Teil 2: Flaschen aus nichtrostendem Stahl

Bouteilles a gaz transportables - Bouteilles a gaz rechargeables soudées en acier -

Conception et construction - Partie 2: Acier inoxydable
Ta slovenski standard je istoveten z: EN 13322-2:2003
ICS:
23.020.30 7ODþQHSRVRGHSOLQVNH Pressure vessels, gas
MHNOHQNH cylinders
SIST EN 13322-2:2003 en

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------
SIST EN 13322-2:2003
---------------------- Page: 2 ----------------------
SIST EN 13322-2:2003
EUROPEAN STANDARD
EN 13322-2
NORME EUROPÉENNE
EUROPÄISCHE NORM
March 2003
ICS 23.020.30
English version
Transportable gas cylinders - Reffilable welded steel gas
cylinders - Design and construction - Part 2: Stainless 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 2: Acier inoxydable Konstruktion - Teil 2: Flaschen aus nichtrostendem Stahl

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 13322-2:2003 E

worldwide for CEN national Members.
---------------------- Page: 3 ----------------------
SIST EN 13322-2:2003
EN 13322-2:2003 (E)
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 .............................................................................................................................................................9

6 Construction and workmanship.................................................................................................................13

7 New design tests..........................................................................................................................................16

8 Batch tests....................................................................................................................................................18

9 Tests on every cylinder ...............................................................................................................................27

10 Failure to meet test requirements ..............................................................................................................28

11 Records.........................................................................................................................................................28

12 Marking .........................................................................................................................................................28

Annex A (normative) Radiographic examination of welds ..................................................................................29

Annex B (normative) Description, evaluation of manufacturing defects and conditions for rejection of

welded stainless steel gas cylinders at time of visual inspection..........................................................32

Annex C (informative) Examples of design and batch testing certificates ........................................................35

Annex D (informative) Guidance on the relationship between conformity assessment modules and

clauses of this standard..............................................................................................................................42

Bibliography ..............................................................................................................................................................48

---------------------- Page: 4 ----------------------
SIST EN 13322-2:2003
EN 13322-2:2003 (E)
Foreword

This document (EN 13322-2:2003) 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 D, 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 and B are normative. Annexes C and D 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.
---------------------- Page: 5 ----------------------
SIST EN 13322-2:2003
EN 13322-2:2003 (E)
Introduction

The purpose of this European Standard is to provide a specification for the design, manufacture, and testing of

refillable, transportable, welded stainless 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.
---------------------- Page: 6 ----------------------
SIST EN 13322-2:2003
EN 13322-2:2003 (E)
1 Scope

This European Standard specifies minimum requirements concerning material, design, construction and

workmanship, manufacturing processes and testing of refillable transportable welded stainless steel gas cylinders

of water capacities from 0,5 l up to and including 150 l for compressed, liquefied and dissolved gases. This

standard is only applicable to cylinders manufactured from stainless steels having a maximum tensile strength of

less than 1 100 MPa.

For acetylene service, additional requirements for the cylinder and the basic requirements for the porous mass are

given in EN 1800.

This standard is primarily for industrial gases other than LPG but may also be applied for LPG.

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 1800, Transportable gas cylinders - Acetylene cylinders - Basic requirements and definitions.

EN 1968, Transportable gas cylinders - Periodic inspection and testing of seamless steel gas cylinders.

EN 10002-1, Metallic materials - Tensile testing - Part 1: Method of test at ambient temperature.

EN 10028-7, Flat products made of steels for pressure purposes - Part 7: Stainless steels.

EN 10045-1, Metallic materials - Charpy impact test - Part 1: Test method.
EN 10088-1, Stainless steels - Part 1: List of stainless steels.

EN 10088-2, Stainless steels - Part 2: Technical delivery conditions for sheet/plate and strip for general purposes.

EN 12517, Non-destructive examination of welds - Radiographic examination of welded joints - Acceptance levels.

---------------------- Page: 7 ----------------------
SIST EN 13322-2:2003
EN 13322-2:2003 (E)
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 3651-2, Determination of resistance to intergranular corrosion of stainless steels - Part 2: Ferritic, austenitic

and ferritic-austenitic (duplex) stainless steels - Corrosion test in media containing sulfuric acid (ISO 3651-2:1998).

EN ISO 6506-1, Metallic materials - Brinell hardness test - Part 1: Test method (ISO 6506-1:1999).

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

Metallic materials (ISO 11114-1:1997).
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 0,2 % proof stress (R ), or, for austenitic steels in the solution annealed condition,

p0,2
1 % proof stress (R )
p1,0
3.1.2
solution annealing

softening heat treatment for austenitic steels in which a cylinder is heated to a uniform temperature above the

upper critical point (AC , as defined in EN 10052) of the steel followed by rapid cooling

3.1.3
cryoforming

process where the cylinder is subjected to a controlled low temperature deformation treatment that results in a

permanent increase in strength
3.1.4
cold working

plastic deformation treatment given to sheet material at ambient temperature, with the aim of permanently

increasing the material strength
3.1.5
coldforming

final deformation treatment at ambient temperature given to the prefabricated cylinder, known as the preform,

which results in a permanent increase in the material strength
3.1.6
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, if applicable, 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.
3.1.7
design stress factor (F)

ratio of equivalent wall stress at test pressure (p ) to guaranteed minimum yield stress (R )

h e
---------------------- Page: 8 ----------------------
SIST EN 13322-2:2003
EN 13322-2:2003 (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 Mean wall thickness, in millimetres, of the cylindrical shell of the cylinder preform

A Percentage elongation after fracture
b Calculated minimum thickness, in millimetres, of the cylinder end

b' Guaranteed minimum thickness, in millimetres, of the cylinder end (including corrosion allowance, 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 10),
D Mean diameter of the cylindrical shell of a cylinder preform, in millimetres
F Design stress factor (see 3.1.7)
f Cryoforming factor established by the manufacturer for each batch of cylinders
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 A)
L Length, in millimetres, of the cylinder

n Ratio of diameter of bend test former (D ) to the thickness of the test piece (t)

p Measured burst pressure, in bar , above atmospheric pressure, in the burst test

p Cryoforming or coldforming pressure in bar , above atmospheric pressure
p Hydraulic test pressure, in bar , above atmospheric pressure
p Observed yield pressure, in bar , above atmospheric pressure
r Inside radius of the 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

R Value of the actual yield stress in megapascals determined by the tensile test
1 bar = 10 Pa = 0,1 MPa
---------------------- Page: 9 ----------------------
SIST EN 13322-2:2003
EN 13322-2:2003 (E)

R Minimum value of 0,2 % proof stress in megapascals, guaranteed by the cylinder manufacturer for the

p0,2
finished cylinder, in accordance with EN 10002-1. (See Note)

R Minimum value of 1,0 % proof stress in megapascals, guaranteed by the cylinder manufacturer for the

p1,0
finished cylinder, in accordance with EN 10002-1. (See Note)

R Minimum value of tensile strength, in megapascals, guaranteed by the cylinder manufacturer for the finished

cylinder

R Actual value of tensile strength, in megapascals, determined by tensile test (see 8.4)

t Actual thickness of the test specimen, in millimetres (see Figure 7)

NOTE For cryoformed and coldformed cylinders the minimum value guaranteed by the manufacturer refers only to the

cylindrical part of the finished cylinder.
4 Materials and heat treatment
4.1 General

4.1.1 Materials of shells and end pressings shall be stainless steels in a condition suitable for pressing or

drawing and welding and shall conform to EN 10088-1 or EN 10028-7.

4.1.2 Grades of steel used for the cylinder manufacture shall be compatible with the intended gas service (e.g.

corrosive gases, embrittling gases) in accordance with EN ISO 11114-1.

4.1.3 There is a risk of sensitisation to intergranular corrosion resulting from the hot processing of austenitic and

duplex stainless steels. An intergranular corrosion test in accordance with 7.3.3 shall be carried out on such

stainless steels when intended to be used for corrosive applications. Corrosive gases are listed in EN 1968, and

cylinders for such gases shall be stamp marked "HG" as specified in EN 1089-1.

4.1.4 The manufacturer shall be able to guarantee cylinder steel casting traceability for each cylinder.

4.1.5 All parts welded to the cylinder shall be made of compatible material with respect to the weldability.

4.1.6 The cylinder 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 and for the welding consumables.

4.1.7 Some grades of stainless steel may be susceptible to environmental stress corrosion cracking. Special

precautions shall be taken in such cases.

4.1.8 The welding consumables shall be such that they are capable of giving consistent welds with minimum

tensile strengths at least equal to that specified for the parent materials (R ) in the finished cylinder.

4.1.9 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 Categories
The following four broad categories of stainless steels are recognised:
ferritic;
martensitic;
austenitic;
ferritic/austenitic (duplex).
---------------------- Page: 10 ----------------------
SIST EN 13322-2:2003
EN 13322-2:2003 (E)
The steels used shall be in accordance with EN 10088-1 or EN 10028-7.
4.3 Heat treatment

4.3.1 For cylinders subjected to coldforming or cryoforming processes, heat treatment of the pre-form component

part is not required. Cold-formed or cryoformed cylinders shall not be subjected to any subsequent heat treatment

or to additional heat application, such as welding.

4.3.2 For other types of stainless steel cylinders, components used for the manufacture of pressure retaining

parts of the cylinders shall be annealed for martensitic and ferritic steels, or solution annealed for austenitic and

duplex steels.

4.3.3 The cylinder manufacturer shall obtain and provide certificates for the heat treatment of all pressure

retaining parts used for the construction of the gas cylinders.
4.4 Test requirements

The material of the finished cylinders shall satisfy the requirements of clause 7.

5 Design
5.1 General requirements

5.1.1 The calculation of the wall thickness of the pressure containing 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

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 not be less than that calculated using the formula:

10.F.J.R - 3.p
e h
a = 1-
2 10.F.J.R
Ł ł
0,65
where the value of F is the lesser of or 0,77.
(R / R )
e g
R /R shall not exceed 0,85.
e g
The value of J shall be selected in accordance with annex A.
The minimum wall thickness shall also satisfy the requirements of 5.4.
---------------------- Page: 11 ----------------------
SIST EN 13322-2:2003
EN 13322-2:2003 (E)
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 D; h b (see Figure 1a)

for ellipsoidal ends (see Figure 1b): H  D; h b (see Figure 1b)

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 graph given in Figure 2 or Figure 3.

5.3.3 For cryoformed cylinders, convex ends shall be hemispherically shaped. The shape factor C shall be

equal to 1.

The minimum 1,0 % proof stress to be achieved in the hemispherical ends shall be equal to:

R = R · (a ‚ 2b )
p p0,1 b b
---------------------- Page: 12 ----------------------
SIST EN 13322-2:2003
EN 13322-2:2003 (E)
a) Torispherical b) Ellipsoidal
Figure 1 — Illustration of cylinder ends
---------------------- Page: 13 ----------------------
SIST EN 13322-2:2003
EN 13322-2:2003 (E)
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 of the end b shall be not less than the value

derived from the appropriate one of the following formulae:
---------------------- Page: 14 ----------------------
SIST EN 13322-2:2003
EN 13322-2:2003 (E)
for D £ 100 mm, a = b = 1,1 mm;
for 100 mm < D £ 150 mm, a = b = 1,1 + 0,008 (D-100) mm;
for D > 150 mm,
a = b = + 0,7 mm, with an absolute minimum of 1,5 mm.
250

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).
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 cylinder.

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 preform shall be produced either 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 coldworked tube or plate; or
using welded deep drawn parts; or
using coldforming or cryoforming of welded cylinder pre-forms.
---------------------- Page: 15 ----------------------
SIST EN 13322-2:2003
EN 13322-2:2003 (E)
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 Cryoforming procedure

6.3.1 Cryoforming as defined in 3.1.3 is a method to increase the mechanical properties especially of metastable

austenitic steels by applying a high internal pressure to the vessel preform at cryogenic temperatures.

The relevant process parameters are the cryoforming pressure p and the cryoforming temperature.

The design of the finished cylinder shall be in accordance with clause 5.

6.3.2 The cryoforming operation shall be carried out at a cryoforming pressure p , which shall be calculated

according to:
f · R · 20 · a
c p1,0 m
p =

f depends on the cryoforming temperature, the cast analysis for each batch of cylinders and the yield strength to

be achieved and shall be established by the manufacturer so that the finished cylinders satisfy the requirements as

specified in clauses 5 and 7. Between batches of one design of cylinder (as defined in 7.3.1), f shall not vary by

more than ± 10 %.

6.3.3 For each cryoformed cylinder, the manufacturer shall record a pressure-time diagram of the cryoforming

process where the rate of pressure increase, the achieved cryoform pressure and the holding time are shown. The

rate of pressure increase shall not be more and the holding time shall not be less than that established during the

design testing for the cylinder.

6.3.4 The maximum permanent deformation of the vessel’s perimeter due to the cryoforming shall be no more

than 15 %.

6.3.5 The cryoforming temperature shall remain constant during the process (e.g. by submerging the cylinder

preform in a suitable cryogenic liquid), and shall be established during the design test.

6.4 Welded joints of pressure containing parts

6.4.1 The longitudinal joint, of which there shall be not more than one, shall be butt-welded.

6.4.2 Circumferential joints of which there shall be no more than two in the cylindrical part, shall be butt-welded

in all cases for cryoformed cylinders and for all cylinders used in corrosive gas applications.

6.4.3 For acetylene service, the joints shall be designed in such a way as to eliminate the risk of damaging the

porous mass.
6.5 Non-pressure-containing attachments

6.5.1 Parts which are not submitted to pressure, such as footrings, handles and neckrings shall be made of steel

compatible with that of the cylinder.

6.5.2 Each attachment shall be designed to permit inspection of the attachment welds, shall be clear of

longitudinal and circumferential joints, and so designed as to avoid trapping water.

6.5.3 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.
---------------------- Page: 16 ----------------------
SIST EN 13322-2:2003
EN 13322-2:2003 (E)

6.5.4 In case of cylinders subjected to a cold-forming or cryoforming process, the non-pressure retaining

attachments shall be welded to the cylinder preform before cold-forming or cryoforming.

6.6 Valve protection

6.6.1 Valves of cylinders of more than 5 litre 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).

6.6.2 When a protective shroud is used, it shall fulfil the requirements of the drop test as described in EN 962.

6.6.3 The requirements of 6.6.1 and 6.6.2 may be waived when the cylinders are intended to be conveyed in

bundles or cradles, or when some other effective valve protection is provided.
6.7 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.
6.8 Visual examination
6.8.1 Unacceptable defects

Before assembly, the pressure envelope parts of the cylinder shall be examined for uniform quality and freedom

from unacceptable defects, examples of which are given in annex B.
6.8.2 Welds

6.8.2.1 Before the cylinders are closed, longitudinal welds shall be visually examined from both sides.

Permanent backing strips shall not be used with longitudinal welds.

6.8.2.2 All welds shall have a smooth finish without concavity and shall merge into the parent material without

under-cutting or abrupt irregularity.
6.8.2.3 All welds shall have full penetration.
6.8.2.4 Radiographic examinat
...

Questions, Comments and Discussion

Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.