EN 730-2:2002

SLOVENSKI STANDARD
01-maj-2003
1DGRPHãþD
SIST EN 730:1997
Oprema za plamensko varjenje - Varnostne naprave - 2. del: Brez vgrajene
varovalke proti povratnemu udaru
Gas welding equipment - Safety devices - Part 2: Not incorporating a flame (flashback)
arrestor
Gasschweißgeräte - Sicherheitseinrichtungen - Teil 2: Ohne integrierte Flammensperre
Matériel de soudage aux gaz - Dispositifs de sécurité - Partie 2: Sans arret de flamme
Ta slovenski standard je istoveten z: EN 730-2:2002
ICS:
25.160.30 Varilna oprema Welding equipment
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 730-2
NORME EUROPÉENNE
EUROPÄISCHE NORM
October 2002
ICS 25.160.30
English version
Gas welding equipment - Safety devices - Part 2: Not
incorporating a flame (flashback) arrestor
Matériel de soudage aux gaz - Dispositifs de sécurité - Gasschweißgeräte - Sicherheitseinrichtungen - Teil 2:
Partie 2: Sans arrêt de flamme Ohne integrierte Flammensperre
This European Standard was approved by CEN on 8 August 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,
Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, 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
© 2002 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 730-2:2002 E
worldwide for CEN national Members.

Contents
page
Foreword.3
1 Scope .4
2 Normative references .4
3 Terms and definitions.4
4 Design and materials.6
4.1 Connections .6
4.2 Materials.6
5 Requirements .7
5.1 General.7
5.2 Gas tightness .7
5.3 Pressure resistance.7
5.4 Non-return valve .8
5.5 Pressure relief valves .8
5.6 Excess flow cut-off valves .8
5.7 Flashback resistance.8
6 Methods for type testing .8
6.1 General.8
6.2 Accuracy of pressure and flow measurements.8
6.3 Test gases.8
6.4 Gas tightness test.9
6.5 Pressure resistance test .9
6.6 Non-return valve test .9
6.7 Pressure relief valves .9
6.8 Excess flow cut-off valve .9
6.9 Internal leakage test for cut-off valves .10
7 Manufacturer’s instructions.10
8 Marking .10
Annex A (informative)  Gas flow measurement.12
A.1 General.12
A.2 Procedure .12
Annex B (informative)  Third party testing information.14
B.1 General.14
B.2 Samples and documentation.14
Foreword
This document EN 730-2:2002 has been prepared by Technical Committee CEN/TC 121 "Welding", the secretariat
of which is held by DS.
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 April 2003, and conflicting national standards shall be withdrawn at the latest by
April 2003.
This European Standard “Gas welding equipment – Safety devices” consists of the following Parts:
Part 1: Incorporating a flame (flashback) arrestor.

 Part 2: Not incorporating a flame (flashback) arrestor.
This Part and EN 730-1 supersedes EN 730:1995.
Annexes A and B 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, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Spain,
Sweden, Switzerland and the United Kingdom.
1 Scope
This Part of this European Standard specifies the general requirements and tests for safety devices for fuel gases
and oxygen or compressed air which do not incorporate a flame (flashback) arrestor used downstream of manifold,
cylinder and (or) pipeline outlet regulators, and upstream of blowpipes for welding, cutting and allied processes.
This standard does not specify the location of these devices in the gas system.
This standard does not include requirements for safety devices which incorporate a flame arrestor which are
covered by EN 730-1.
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 the 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 560, Gas welding equipment — Hose connections for equipment for welding, cutting and allied processes.
EN 561, Gas welding equipment — Quick-action coupling with shut-off valves for welding, cutting and allied
processes.
EN 730-1:2002, Gas welding equipment — Safety devices — Part 1: Incorporating a flame (flashback) arrestor.
EN 29090, Gas tightness of equipment for gas welding and allied processes (ISO 9090:1989).
EN 29539, Materials for equipment used in gas welding, cutting and allied processes (ISO 9539:1988).
EN ISO 2503, Gas welding equipment — Pressure regulators for gas cylinders used in welding, cutting and allied
processes up to 300 bar (ISO 2503:1998).
EN ISO 7291, Gas welding equipment - Pressure regulators for manifold systems used in welding, cutting and allied
processes up to 300 bar (ISO 7291:1999).
ISO 554, Standard atmospheres for conditioning and/or testing — Specifications.
3 Terms and definitions
For the purposes of this European Standard, the following terms and definitions apply.
3.1
excess flow cut-off valve
device which stops the gas flow in the event of flow exceeding a predetermined value
EXAMPLE Valve is held open by a spring; it closes when the force caused by the dynamic pressure becomes greater than
the force of the spring. A resetting device is necessary.
Key
1 Normal direction of gas flow
Figure 1 — Excess flow cut-off valve (example)
3.2
maximum operating pressure
maximum pressure to which the equipment may be subjected in service
3.3
multifunctional safety device
device which incorporates two or more of the safety functions
EXAMPLE Non-return valve and excess flow cut-off valve.
3.4
non-return valve
device which prevents passage of gas in the direction opposite to flow
EXAMPLE Valve is held open by energy in gas stream and closes when downstream pressure is approximately equal to
or greater than that in normal direction of flow.
Key
1 Normal direction of gas flow
Figure 2 — Non-return valve (example)
3.5
pressure relief valve
device which automatically vents gas when the pressure exceeds some predetermined value and seals again when
the pressure returns to within specified limits of that value
EXAMPLE Valve is held closed by a spring; it opens when force caused by internal pressure rise exceeds the spring load.
Figure 3 — Pressure relief valve (example)
3.6
safety device
device for welding equipment which averts risk in case of misuse or malfunction of the down-stream gas welding
equipment
4 Design and materials
4.1 Connections
Threaded connections up to G1 shall be in accordance with EN 560. Quick release connections shall be in
accordance with EN 561.
4.2 Materials
Materials used for safety devices shall conform to the requirements laid down in EN 29539.
5 Requirements
5.1 General
A summary of the requirements and test sequence for each device is given in Table 1.
Table 1 — Summary of requirements and test sequence for safety devices
Safety device Require- Tests (in test order) Number of Total number of
function(s) ments devices required devices required
(Clause No)
(Clause for each test
No)
Non-return valve 5.2.1 6.4 External gas tightness 5 6
a
5.2.2 6.5 Pressure resistance
5.3 6.6 Reverse flow 5
5.4 6.9 Internal leakage
Pressure relief valve 5.2.1 6.4 External gas tightness 5 6
a
5.3 6.5Pressure resistance
5.5 6.7 Relief pressure and 5
flow
Excess flow cut-off 5.2.1 6.4 External gas tightness 5 6
a
valve 5.2.2 6.5Pressure resistance 1
5.3 6.8Excess flow cut-off 5
5.6 6.9 Internal leakage 5
a
Use a new device for this test. Do not use for any other test.
NOTE In the following sub-clauses, the terms “upstream” and “downstream” refer to the normal direction of gas flow in the
device.
5.2 Gas tightness
5.2.1 External gas tightness
The general requirements on external gas tightness and the test procedures shall be in accordance with EN 29090.
5.2.2 Internal Gas Tightness
Where internal gas tightness is required in this standard the leakage rate shall not exceed 50 cm /h for devices
with a connection internal bore (diameter) less than 11 mm or 0,41 d for larger diameters (for tests see 6.6 and/or
6.9).
2 3
NOTE The value 0,41 d is the flow in cm /h where d is the internal bore (diameter) in mm of the largest connection of the
device.
5.3 Pressure resistance
The housings of the safety devices shall resist a pressure equal to ten times the maximum operating pressure, with
the test pressure in all cases not less than 60 bar ).
...