EN ISO 2503:1998

SLOVENSKI STANDARD
SIST EN ISO 2503:1999
01-december-1999
1DGRPHãþD
SIST EN 585:1995
Oprema za plamensko varjenje - Regulatorji tlaka za plinske jeklenke za varjenje,
rezanje in sorodne postopke do 300 bar (ISO 2503:1998)
Gas welding equipment - Pressure regulators for gas cylinders used in welding, cutting
and allied processes up to 300 bar (ISO 2503:1998)
Druckminderer für Gasflaschen für Schweißen, Schneiden und verwandte Verfahren bis
300 bar (ISO 2503:1998)
Matériel de soudage aux gaz - Détendeurs pour bouteilles de gaz utilisés pour le
soudage, le coupage et les techniques connexes jusqu'a 300 bar (ISO 2503:1998)
Ta slovenski standard je istoveten z: EN ISO 2503:1998
ICS:
23.020.30 7ODþQHSRVRGHSOLQVNH Pressure vessels, gas
MHNOHQNH cylinders
23.060.40 7ODþQLUHJXODWRUML Pressure regulators
25.160.30 Varilna oprema Welding equipment
SIST EN ISO 2503:1999 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN ISO 2503:1999SIST EN ISO 2503:1999

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SIST EN ISO 2503:1999SIST EN ISO 2503:1999

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SIST EN ISO 2503:1999SIST EN ISO 2503:1999

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SIST EN ISO 2503:1999SIST EN ISO 2503:1999
INTERNATIONAL ISO
STANDARD 2503
Second edition
1998-04-01
Gas welding equipment — Pressure
regulators for gas cylinders used in
welding, cutting and allied processes
up to 300 bar
Matériel de soudage au gaz — Détendeurs pour bouteilles de gaz utilisés
pour le soudage, le coupage et les techniques connexes jusqu'à 300 bar
A
Reference number
ISO 2503:1998(E)

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SIST EN ISO 2503:1999SIST EN ISO 2503:1999
ISO 2503:1998(E)
Contents Page
1 Scope . 1
2 Normative references . 1
3 Definition . 1
4 Terminology . 2
 . 4
5Units
5.1 Pressure . 4
5.2 Flow . 4
5.3 Temperature . 4
6 Manufacturing requirements . 4
6.1 Materials . 4
6.2 Design, machining and assembly . 4
. 6
7 Types of connections
7.1 Inlet connections . 6
7.2 Outlet connections . 6
8 Physical characteristics . 6
8.1 Pressures . 7
8.2 Flow rates . 7
8.3 Equipment classes . 8
8.4 Operating characteristics . 8
9 Marking . 9
10 Instructions for use . 10
11 Type test procedure . 10
11.1 General . 10
11.2 Test samples and necessary documents . 11
11.3 Test conditions . 11
11.4 Functional tests . 11
11.5 Mechanical tests . 14
11.6 Test for durability of markings . 16
©  ISO 1998
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 central@iso.ch
X.400 c=ch; a=400net; p=iso; o=isocs; s=central
Printed in Switzerland
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SIST EN ISO 2503:1999SIST EN ISO 2503:1999
©
ISO ISO 2503:1998(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.
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 2503, was prepared by Technical Committee
ISO/TC 44, Welding and allied processes, Subcommittee SC 8, Equipment
for gas welding, cutting and allied processing.
This second edition cancels and replaces the first edition (ISO 2503:1983),
which has been technically revised.
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SIST EN ISO 2503:1999SIST EN ISO 2503:1999
©
INTERNATIONAL STANDARD  ISO ISO 2503:1998(E)
Gas welding equipment — Pressure regulators for gas cylinders
used in welding, cutting and allied processes up to 300 bar
1 Scope
This International Standard specifies requirements for single or two-stage pressure regulators for connections to gas
1)
cylinders normally used for compressed gases up to 300 bar (30 MPa), for dissolved acetylene, for liquefied petroleum
gases (LPG), methylacetylene-propadiene-mixtures (MPS) and carbon dioxide (CO ) used in welding, cutting and allied
2
processes.
2 Normative references
The following standards contain provisions which, through reference in this text, constitute provisions of this International
Standard. At the time of publication, the editions indicated were valid. All Standards are subject to revision, and parties to
agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent
editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International
Standards.
ISO 554:1976, Standard atmospheres for conditioning and/or testing — Specifications.
ISO 3253:1998, Gas welding equipment — Hose connections for equipment for welding, cutting and related processes.
ISO 5171:1995, Pressure gauges used in welding, cutting and allied processes.
ISO/TR 7470:1988, Valve outlets for gas cylinders — List of provisions which are either standardized or in use.
ISO 9090:1989, Gas tightness of equipment for gas welding and allied processes.
ISO 9539:1988, Materials for equipment used in gas welding, cutting and allied processes.
3 Definition
For the purposes of this International Standard, the following definition applies.
3.1  pressure regulator: Device for regulating a generally variable inlet pressure to an as constant as possible outlet
pressure.

1)  300 bar relates to maximum cylinder charging pressure at 15 °C.
1

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ISO 2503:1998(E) ISO
4 Terminology
The terms relating to pressure regulators are given in the key to figure 1 given in table 1. The diagram of the pressure
regulator is an example only.
NOTES
1  Parts 12, 13 and 14 are components of the relief valve
2  Part 27 is an outlet valve and its installation is optional, see 6.2.4.
3  Parts 4a and 4b of the drawing are examples and are not specified. Other types of inlet connection pieces are also in use.
Figure 1 — Diagram of a pressure regulator and designation of its components
2

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SIST EN ISO 2503:1999SIST EN ISO 2503:1999
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ISO ISO 2503:1998(E)
Table 1 — List of terms
No. English French German
1 pressure adjusting screw vis de réglage Einstellschraube
2 spring plate plateau de membrane Federteller
3 body corps Körper
4a inlet stem raccord d'entrée Eingangsstutzen
4b inlet nut écrou flottant Schraubverbindung
raccord d'entrée
5 inlet filter filtre d'entrée Eintrittsfilter
6 seating washer joint de manomètre Manometeranschluß-
Dichtungsring
7 high-pressure gauge manomètre haute pression Hochdruckmanometer
(amont)
8 pressure regulator valve cap bouchon de clapet Regelventilkappe
9 pressure regulator valve spring ressort de clapet Regelventilfeder
10 spring centre appui mobile de centrage du Regelventil-Federteller
ressort de clapet
11 pressure regulator valve clapet Regelventil
12 relief valve cap vis de réglage de la soupape Einstellschraube des
de sécurité Abblaseventils
13 relief valve spring ressort de soupape de sécurité Feder für Abblaseventil
14 relief valve seat clapet de soupape de sécurité Abblaseventilsitz
15 low-pressure gauge manomètre basse pression Niederdruckmanometer
(aval)
16 pressure regulator valve seat siège Regelventilsitz
17 pressure regulator valve pin poussoir Regelventilstift
18 diaphragm plate plateau d'appui du poussoir Membranteller
19 diaphragm membrane Membran
20 outlet connection piece raccord de sortie Abgangsstutzen
(mamelon fileté)
21 union nut écrou de douille Überwurfmutter
22 hose tail douille porte-tuyau Schlauchtülle
23 diaphragm seal joint de membrane Membrangleitring
24 pressure regulator spring ressort de détente Stellfeder
25 pressure regulator cover couvercle Federdeckel
26 pressure regulator spring plate appui mobile de centrage du Stellfederteller
ressort de détente
27 outlet valve robinet de sortie Absperrventil
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ISO 2503:1998(E) ISO
5 Units
5.1 Pressure
2)
The pressures measured are gauge pressures and are expressed in bar.
5.2 Flow
3 3)
Flow rates are measured in cubic metres per hour (m /h) at normal conditions taking into account the relevant conversion
coefficient for the gas used (see table 2).
Table 2 — Conversion coefficient, U
Conversion coefficient
Test gas air oxygen nitrogen argon hydro- helium acety- LPG, CO
2
gen lene e.g.
propane
air 1 0,950 1,02 0,851 3,81 2,695 1,05 0,800 0,808
nitrogen 0,983 0,930 1 0,837 3,75 2,65 1,03 0,784 0,792
Conversion coefficient, U, is based on the formula:
g
0
U =
g
1
where
is the specific weight of test gas;
g
0
g is the specific weight of gas used.
1
5.3 Temperature
Temperatures are measured in degrees Celsius.
6 Manufacturing requirements
6.1 Materials
Materials for pressure regulators shall conform to the requirements of ISO 9539.
6.2 Design, machining and assembly
6.2.1 Oxygen regulators
Regulators for oxygen shall be designed, machined and manufactured such that internal ignition does not occur (see 11.5.3).
All components and accessories shall be thoroughly cleaned and degreased before assembly.

2)  Pressure exceeding atmospheric pressure.
3)  Normal conditions are given in ISO 554.
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ISO ISO 2503:1998(E)
6.2.2 Acetylene regulators
Regulators for acetylene shall be designed and manufactured so that the outlet pressure shall not exceed 1,5 bar.
6.2.3 Filter
A dust filter, having an effective cross-section compatible with the discharge, shall be mounted within the pressure regulator
upstream of the pressure regulator valve. The filter shall not be removable without the use of a tool. The filter shall retain
particles greater than or equal to 0,1 mm.
6.2.4 Outlet valve
Pressure regulators can be fitted with an outlet valve. When fitted, the spindle shall be captive.
6.2.5 Pressure adjusting device
This device shall be designed in such a way that it is not possible for the pressure regulator valve to be held in the open
position, for example, as a consequence of the spring being compressed fully (to its solid length).
If the dimensions of the pressure adjusting screw are such as to prevent the spring becoming fully compressed, then the
pressure adjusting screw shall be not removable.
Using the adjusting device, it shall not be possible to set a pressure at which the relief valve vents.
6.2.6 Relief valve
6.2.6.1 General
The fitting of a relief valve is obligatory for all compressed gases and carbon dioxide and optional for LPG, MPS and
acetylene.
The minimum discharge Q of the relief valve, if fitted, shall be equal to or greater than the standard discharge Q (see
RV 1
tables 3 and 4) for a pressure p defined by the expression p = 2p , except in the case of acetylene regulators, where p
RV RV 2 RV
shall be equal to 3 bar for all classes.
With decreasing pressure the relief valve shall close at a pressure greater than p . The relief valve shall be non-adjustable by
2
the user.
Relief valve for compressed gases and carbon dioxide
6.2.6.2
The relief valve shall remain gas tight to a pressure above the maximum outlet pressure achieved when the flow is shut off
for the initial pressure p . The relief valve shall be fitted in such a way that the gas discharges safely.
3
6.2.6.3 Relief valve for acetylene
The relief valve, if fitted, shall remain gas tight to a pressure above 1,5 bar. It shall be fitted in such a way that the gas is not
discharged towards to the operator.
6.2.6.4 Relief valve for LPG and MPS
The relief valve, if fitted, shall conform to 6.2.6.2.
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ISO 2503:1998(E) ISO
6.2.7 Pressure gauges
When fitted externally, pressure gauges shall conform to ISO 5171. If pressure gauges are integral with the regulator, the
relevant operational and safety requirements stipulated in ISO 5171 shall apply.
6.2.8 Gas tightness
Pressure regulators shall be gas tight to the atmosphere and shall conform to the requirements of ISO 9090.
Pressure regulators shall be internally gas tight, i.e. between the high pressure and low pressure parts for all normal
3
pressures for relevant gases. The maximal internal leakage shall not exceed 0,2 mbar l/min (12 cm /h).
6.2.9 Mechanical resistance
 Fitness for service
6.2.9.1
Pressure regulators shall be designed and constructed in such a way that the application of pressures given in table 6 in the
high pressure and low pressure chambers does not lead to permanent deformation.
6.2.9.2 Safety
Pressure regulators shall be designed and constructed so that if the low pressure chamber of the regulator, or intermediate
chamber in the case of two-stage regulators, is in direct communication with a full cylinder of gas, for instance if the regulator
valve is held in the open position and the outlet connection is closed (by an attached stop valve or a blind plug) the high-
pressure gas shall either be safely retained or vented (see 11.5.1.2).
7 Types of connections
7.1 Inlet connections
Pressure regulators shall be made in such a way that the inlet connection is compatible with the cylinder valve outlet
designed for the gas contained (see ISO/TR 7470). The inlet pressure p specified by the manufacturer, shall be not less
1
than the maximum charging pressure (at 15 °C) permitted for the cylinder connection.
7.2 Outlet connections
Threaded outlet connections shall conform to ISO 3253 and comply with the following conditions:
– the outlet connection orientation should preferably point downwards and away from the cylinder;
– curved hose tails shall not be used.
8 Physical characteristics
The symbols used are given in table 3.
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ISO ISO 2503:1998(E)
Table 3 — Symbols used
Symbol Explanation
p rated (maximum) inlet pressure
1
p rated (maximum) outlet pressure
2
p acetylene outlet pressure used for calculation of R (see 11.4.4)
2R
p acetylene outlet pressure used for calculation of i (see 11.4.5)
2i
p upstream pressure for type testing: p = 2p + 1 bar (0,1 MPa)
3 3 2
p stabilized outlet pressure (s
...