EN ISO 11120:1999

SLOVENSKI STANDARD
01-januar-2000
Plinske jeklenke - Ponovno polnljive velike jeklenke iz celega iz jekla za transport
stisnjenega plina vodne prostornine od 150 do 3000 l - Konstruiranje, izdelava in
preskušanje
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)
Ortsbewegliche Gasflaschen - Nahtlose wiederbefüllbare Großflaschen aus Stahl mit
einem Fassungsraum zwischen 150 l und 3000 l - Gestaltung, Konstruktion und Prüfung
(ISO 11120:1999)
Bouteilles a gaz - Tubes en acier sans soudure rechargeables d'une contenance en eau
de 150 l a 3000 l - Conception, construction et essais (ISO 11120:1999)
Ta slovenski standard je istoveten z: EN ISO 11120:1999
ICS:
23.020.30 7ODþQHSRVRGHSOLQVNH Pressure vessels, gas
MHNOHQNH cylinders
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

INTERNATIONAL ISO
STANDARD 11120
First edition
1999-03-15
Gas cylinders — Refillable seamless steel
tubes of water capacity between 150 l and
3 000 l — Design, construction and testing
Bouteilles à gaz — Tubes en acier sans soudure rechargeables
d'une contenance en eau de 150 l à 3 000 l — Conception, construction
et essais
A
Reference number
ISO 11120:1999(E)
ISO 11120:1999(E)
Contents Page
1 Scope .1
2 Normative references .1
3 Definitions .2
4 Symbols.3
5 Inspection and testing.3
6 Materials .3
7 Design.6
8 Construction and workmanship.7
9 Batch tests.8
10 Tests on every cylinder.9
11 Special requirements for tubes for embrittling gases .11
12 Marking .13
Annex A (normative) ISO High-pressure gas tube/cylinder chemistry groupings.14
Annex B (normative) Ultrasonic inspection .15
Annex C (informative) Description, evaluation of manufacturing defects and conditions for rejection of
seamless steel tubes at time of visual inspection.20
Annex D (informative) Acceptance certificate .27
(informative)
Annex E Checklist for production testing.29
Bibliography.30
©  ISO 1999
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic
or mechanical, including photocopying and microfilm, without permission in writing from the publisher.
International Organization for Standardization
Case postale 56 • CH-1211 Genève 20 • Switzerland
Internet iso@iso.ch
Printed in Switzerland
ii
© ISO
ISO 11120:1999(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO
member bodies). The work of preparing International Standards is normally carried out through ISO technical
committees. Each member body interested in a subject for which a technical committee has been established has
the right to be represented on that committee. International organizations, governmental and non-governmental, in
liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical
Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 3.
Draft International Standards adopted by the technical committees are circulated to the member bodies for voting.
Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote.
International Standard ISO 11120 was prepared by Technical Committee ISO/TC 58, Gas cylinders, Subcommittee
SC 3, Cylinder design.
Annexes A and B form an integral part of this International Standard.
Annexes C, D and E are for information only.
iii
© ISO
ISO 11120:1999(E)
Introduction
The purpose of this International Standard is to provide a specification for the design, manufacture, inspection and
testing of tubes for worldwide usage. The objective is to balance design and economic efficiency against international
acceptance and universal utility.
This International Standard aims to eliminate concern about climate, duplicate inspections and restrictions currently
existing because of lack of definitive International Standards. This International Standard should not be construed as
reflecting on the suitability of the practice of any nation or region.
iv
INTERNATIONAL STANDARD  © ISO ISO 11120:1999(E)
Gas cylinders — Refillable seamless steel tubes of water capacity
between 150 l and 3 000 l — Design, construction and testing
1 Scope
This International Standard specifies minimum requirements for the material, design, construction and
workmanship, manufacturing processes and tests at manufacture of refillable quenched and tempered seamless
steel tubes of water capacities from 150 l up to and including 3 000 l for compressed and liquefied gases exposed to
extreme world-wide ambient temperatures (normally between 250 °C and 165 °C). This International Standard is
applicable to tubes with a maximum tensile strength R of less than 1 100 MPa.
m
These tubes can be used alone or in batteries to equip trailers or skids (ISO modules) for the transportation and
distribution of compressed gases.
This International Standard does not include consideration of any additional stresses that may occur during service
or transport, e.g. bending stresses, etc.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of this
International Standard. For dated references, subsequent amendments to, or revisions of, any of these publications do
not apply. However, parties to agreements based on this International Standard are encouraged to investigate the
possibility of applying the most recent editions of the normative documents indicated below. For undated references,
the latest edition of the normative document referred to applies. Members of ISO and IEC maintain registers of
currently valid International Standards.
1)
ISO 148 , Steel — Charpy impact test (V-notch).
2)
ISO 6506 , Metallic materials — Hardness test — Brinell test.
ISO 6892, Metallic materials — Tensile testing at ambient temperature.
ISO 11114-1, Transportable gas cylinders — Compatibility of cylinder and valve materials with gas contents —
Part 1: Metallic materials.
ISO 11484, Steel tubes for pressure purposes — Qualification and certification of non-destructive testing (NDT)
personnel.
1)
To be replaced by ISO 148-1, ISO 148-2 and ISO 148-3.
2)
To be replaced by ISO 6506-1, ISO 6506-2 and ISO 6506-3.
© ISO
ISO 11120:1999(E)
3 Definitions
For the purposes of this International Standard the following definitions apply.
3.1
yield stress
value corresponding to the 0,2 % proof stress, R
p 0,2
3.2
quenching
hardening heat treatment in which a tube, which has been heated to a uniform temperature above the upper critical
point Ac of the steel, is cooled rapidly in a suitable medium
3.3
tempering
softening heat treatment which follows quenching, in which the tube is heated to a uniform temperature below the lower
critical point Ac of the steel
3.4
tube
a double ended pressure gas cylinder manufactured from seamless tubing
3.5
batch
a quantity of up to 200 tubes of the same nominal diameter, thickness and design made from the same steel cast and
subjected to the same heat treatment for the same duration of time
3.6
test pressure
required pressure (p ) applied during a pressure test
h
3.7
design stress factor
F
ratio of the equivalent wall stress at test pressure (p ) to guaranteed minimum yield stress (R )
h e
© ISO
ISO 11120:1999(E)
4 Symbols
Symbol Definition
a calculated minimum thickness, in millimetres, of the cylindrical shell
a' guaranteed minimum thickness, in millimetres, of the cylindrical shell
A percentage elongation
D nominal outside diameter of the tube, in millimetres
f a constant in the design stress factor (see 11.3)
design stress factor (see 3.7)
F
L original gauge length, in millimetres, according to ISO 6892
a
p
hydraulic test pressure, in bar above atmospheric pressure
h
a
R
guaranteed minimum value of yield stress, in megapascals
e
R value of the actual yield stress, in megapascals, determined by the tensile test
ea
R guaranteed minimum value of the tensile strength, in megapascals
g
R actual value of tensile strength, in megapascals, determined by the tensile test
m
S original cross-sectional area of tensile test piece, in square millimetres, according to ISO 6892
a 1 bar = 100 kPa; 1 MPa = 10 bar.
5 Inspection and testing
Evaluation of conformity is required to be performed in accordance with the relevant regulations of the country(ies)
where the tubes are to be used.
In order to ensure that tubes are in compliance with this International Standard they shall be subject to inspection in
accordance with clauses 9 and 10 by an authorized inspection body (hereafter referred to as “the inspector”)
recognized in the countries of use. The inspector shall be competent for inspection of tubes.
6 Materials
6.1 General requirements
6.1.1  Materials for the manufacture of tubes shall meet the requirements of 6.2, 6.3 and 6.4.
Steels for the fabrication of tubes shall be of nationally or internationally recognized compositions having proven
reliability. These steels shall fall within one of the chemical groups as shown in annex A.
New steel compositions, and steels for which limited experience exists in tube/cylinder service, shall be fully tested and
approved by a national authority and have been manufactured from not less than five casts of steel.
The manufacturer of the finished tube shall provide a detailed specification with tolerances for the supplied tubing
including:
 chemical composition;
© ISO
ISO 11120:1999(E)
 dimensions;
 surface quality.
6.1.2  The steel used for the fabrication of tubes shall be fully killed.
6.1.3  The manufacturer of the tubing shall supply certificates of a reference heat treatment representative of the
final heat treatment.
NOTE Additional requirements related to tubes for use with embrittling gases are given in clause 11.
6.2 Controls on chemical composition
6.2.1  A steel is defined by the steel-making process and by its chemical composition.
Steel-making shall be defined by reference to a given process (oxygen converter, electric arc furnace or equivalent)
and to the killing method.
The chemical composition of the steel shall be defined at least by:
 the carbon, manganese and silicon contents in all cases;
 the chromium, nickel, molybdenum, vanadium or niobium contents when these are alloying elements
intentionally added to the steel;
 the maximum sulphur and phosphorus contents in all cases.
The carbon, manganese and silicon contents and, where appropriate, the chromium, nickel, molybdenum, vanadium or
niobium contents shall be given, with tolerances, such that the differences between the maximum and minimum values
of the cast do not exceed the ranges shown in Table 1.
© ISO
ISO 11120:1999(E)
Table 1 — Chemical composition tolerances
Element Content Permissible range
Carbon , 0,30 % 0,06 %
> 0,30 % 0,07 %
Manganese all contents 0,30 %
Silicon all contents 0,30 %
Chromium , 1,50 % 0,30 %
> 1,50 % 0,50 %
Nickel all contents 0,40 %
Molybdenum all contents 0,15 %
Vanadium all contents 0,10 %
Niobium all contents 0,10 %
Elements not included in the declared chemical composition sha
...