IEC 60974-7:2013
(Main)Arc welding equipment - Part 7: Torches
Arc welding equipment - Part 7: Torches
IEC 60974-7:2013 specifies safety and construction requirements for torches for arc welding and allied processes. This part of IEC 60974 is applicable to manual, mechanically guided, air-cooled, liquid-cooled, motorized, spool-on and fume extraction torches. In this part of IEC 60974, a torch consists of the torch body, the cable-hose assembly and other components. This part of IEC 60974 is also applicable to a cable-hose assembly connected between a power source and ancillary equipment. This part of IEC 60974 is not applicable to electrode holders for manual metal arc welding or air-arc cutting/gouging. This third edition cancels and replaces the second edition published in 2007 and constitutes a technical revision. The significant changes with respect to the previous edition are listed below:
- new requirement for degree of protection of torch coupling device (see Table 1);
- scope is extended to cable-hose assembly connected between a power source and ancillary equipment (see Clause 1);
- torch parts, as recommended by the manufacturer, are included in the safe plasma cutting system design (see 7.4.2);
- new flammability requirement for handle material (see 11.3).
This publication is to be read in conjunction with IEC 60974-1:2012.
Matériel de soudage à l'arc - Partie 7: Torches
La CEI 60974-7:2013 spécifie les règles de sécurité et de construction applicables aux torches pour le soudage à l'arc et les procédés connexes. La présente partie s'applique pour les torches manuelles, guidées mécaniquement, refroidies par air, refroidies par liquide, motorisées, enroulées et avec extraction de fumée. Dans la présente partie de la CEI 60974, une torche comprend le corps de torche, le faisceau et d'autres composants. La présente partie de la CEI 60974 s'applique aussi à un faisceau qui est connecté entre une source de courant de soudage et l'équipement auxiliaire. La présente partie de la CEI 60974 ne s'applique pas aux porte-électrode pour le soudage à l'arc métallique manuel ni au coupage/gougeage air-arc. Cette troisième édition annule et remplace la seconde édition publiée en 2007 et constitue une révision technique. Les modifications principales par rapport à l'édition précédente sont listées ci-après:
- nouvelle exigence pour le degré de protection du dispositif de couplage de la torche (voir Tableau 1);
- domaine d'application élargi au faisceau connecté entre une source de courant et l'équipement auxiliaire (voir Article 1);
- les parties de la torche, recommandées par le fabricant, sont incluses dans la conception sûre du système de coupage plasma (voir 7.4.2);
- nouvelle exigence d'inflammabilité pour le matériel du manche (voir 11.3).
Cette publication doit être lue conjointement avec la CEI 60974-1:2012.
General Information
Relations
Standards Content (Sample)
IEC 60974-7 ®
Edition 3.0 2013-01
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Arc welding equipment –
Part 7: Torches
Matériel de soudage à l'arc –
Partie 7: Torches
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IEC 60974-7 ®
Edition 3.0 2013-01
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Arc welding equipment –
Part 7: Torches
Matériel de soudage à l'arc –
Partie 7: Torches
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX U
ICS 25.160 ISBN 978-2-83220-573-0
– 2 – 60974-7 IEC:2013
CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Environmental conditions . 9
5 Classification . 9
5.1 General . 9
5.2 Process . 9
5.3 Guidance . 9
5.4 Cooling . 9
5.5 Main arc striking for plasma processes . 10
6 Test conditions . 10
6.1 General . 10
6.2 Type tests . 10
6.3 Routine tests . 10
7 Protection against electric shock . 10
7.1 Voltage rating . 10
7.2 Insulation resistance . 11
7.3 Dielectric strength . 12
7.3.1 General requirement . 12
7.3.2 Additional requirements for plasma cutting torches . 12
7.3.3 Additional requirements for striking and stabilizing voltage rating . 12
7.4 Protection against electric shock in normal service (direct contact) . 13
7.4.1 Degree of protection requirements . 13
7.4.2 Additional requirements for plasma cutting torches . 13
8 Thermal rating . 13
8.1 General . 13
8.2 Temperature rise . 13
8.3 Heating test . 14
8.3.1 General . 14
8.3.2 Metal inert/active gas (MIG/MAG) or self-shielded flux-cored arc
welding torch . 14
8.3.3 Tungsten inert gas (TIG) and plasma arc welding torch . 16
8.3.4 Plasma cutting torch . 17
8.3.5 Submerged arc welding torch . 18
9 Pressure of the liquid cooling system . 18
10 Resistance to hot objects . 18
11 Mechanical provisions . 19
11.1 Impact resistance . 19
11.2 Accessible parts . 20
11.3 Handle material . 20
12 Marking . 20
13 Instructions for use . 21
Annex A (informative) Additional terminology . 22
Annex B (normative) Position of the welding torches for the heating test. 25
60974-7 IEC:2013 – 3 –
Annex C (informative) Cooled copper block . 26
Annex D (informative) Copper block with a hole . 27
Annex E (informative) Copper bars with a slot . 28
Bibliography . 29
Figure 1 – Device for testing the resistance to hot objects . 19
Figure 2 – Device for the impact test . 20
Figure A.1 – Torch for metal inert/active gas (MIG/MAG) or self-shielded flux-cored arc
welding . 23
Figure A.2 – Gun for metal inert/active gas (MIG/MAG) or self-shielded flux-cored arc
welding . 23
Figure A.3 – Torch for tungsten inert gas arc welding . 23
Figure A.4 – Torch for plasma arc welding . 23
Figure A.5 – Torch for plasma cutting . 23
Figure A.6 – Supply unit . 23
Figure A.7 – Mechanically guided plasma torch . 24
Figure B.1 – MIG/MAG torches . 25
Figure B.2 – TIG torches . 25
Figure B.3 – Plasma welding torches . 25
Figure C.1 – Water-cooled copper block – Example . 26
Figure D.1 – Water-cooled copper block with a hole – Example . 27
Figure E.1 – Water-cooled copper bars with a slot – Example . 28
Table 1 – Voltage rating of torches . 11
Table 2 – Test values for metal inert gas arc welding (MIG) of aluminium alloys . 15
Table 3 – Test values for metal active gas arc welding (MAG) of mild steel . 15
Table 4 – Test values for metal active gas arc welding (MAG) with flux-cored wire . 16
Table 5 – Test values for self-shielded flux-cored arc welding of mild steel . 16
Table 6 – Test values for tungsten inert gas arc welding (TIG) . 17
Table 7 – Test values for plasma arc welding . 17
Table A.1 – List of terms . 22
– 4 – 60974-7 IEC:2013
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ARC WELDING EQUIPMENT –
Part 7: Torches
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
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patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 60974-7 has been prepared by IEC technical committee 26:
Electric welding.
This third edition cancels and replaces the second edition published in 2005 and constitutes a
technical revision. The significant changes with respect to the previous edition are listed
below:
• new requirement for degree of protection of torch coupling device (see Table 1);
• scope is extended to cable-hose assembly connected between a power source and
ancillary equipment (see Clause 1);
• torch parts, as recommended by the manufacturer, are included in the safe plasma cutting
system design (see 7.4.2);
• new flammability requirement for handle material (see 11.3).
60974-7 IEC:2013 – 5 –
The text of this standard is based on the following documents:
FDIS Report on voting
26/492/FDIS 26/495/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
This part of IEC 60974 is to be used in conjunction with IEC 60974-1.
A list of all parts of the IEC 60974 series can be found, under the general title Arc welding
equipment, on the IEC website.
In this standard, the following print types are used:
– conformity statements: in italic type.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
– 6 – 60974-7 IEC:2013
ARC WELDING EQUIPMENT –
Part 7: Torches
1 Scope
This part of IEC 60974 specifies safety and construction requirements for torches for arc
welding and allied processes. This part of IEC 60974 is applicable to manual, mechanically
guided, air-cooled, liquid-cooled, motorized, spool-on and fume extraction torches.
In this part of IEC 60974, a torch consists of the torch body, the cable-hose assembly and
other components.
This part of IEC 60974 is also applicable to a cable-hose assembly connected between a
power source and ancillary equipment.
This part of IEC 60974 is not applicable to electrode holders for manual metal arc welding or
air-arc cutting/gouging.
NOTE 1 Typical allied processes are electric arc cutting and arc spraying.
NOTE 2 Other components are listed in Table A.1.
NOTE 3 In this part of IEC 60974, the terms "torch" and "gun" are interchangeable. For convenience "torch" has
been used in the following text.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and
are indispensable for its application. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 60050 (all parts), International Electrotechnical Vocabulary (available at
)
IEC 60529, Degrees of protection provided by enclosures (IP Code)
IEC 60664-1, Insulation coordination for equipment within low-voltage systems – Part 1:
Principles, requirements and tests
IEC 60695-11-10, Fire hazard testing – Part 11-10: Test flames – 50 W horizontal and vertical
flame test methods
IEC 60974-1:2012, Arc welding equipment – Part 1: Welding power sources
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60050,
IEC 60664-1, and IEC 60974-1, as well as the following, apply.
NOTE Additional terminology is given in Annex A.
60974-7 IEC:2013 – 7 –
3.1
torch
device that conveys all services necessary to the arc for welding, cutting or allied processes
(for example, current, gas, coolant, wire electrode)
3.2
gun
torch with a handle substantially perpendicular to the torch body
3.3
torch body
main component to which the cable-hose assembly and other components are connected
3.4
handle
part designed to be held in the operator's hand
3.5
gas nozzle
component at the exit end of the torch directing the shielding gas around the arc and over the
weld pool
3.6
non-consumable electrode
arc welding electrode which does not provide filler metal
3.7
wire electrode
solid or tubular filler wire which conducts welding current
3.8
contact tip
replaceable metal component fixed at the front end of the torch, which transfers the welding
current to, and guides, the wire electrode
3.9
cable-hose assembly
flexible assembly of cables and hoses, and their connecting elements, that delivers supplies
to the torch body or ancillary equipment
3.10
manual torch
torch held and guided by the operator's hand during its operation
3.11
mechanically guided torch
torch fixed to, and guided by, a mechanical device during its operation
3.12
air-cooled torch
torch cooled by the ambient air and, where appropriate, by the shielding gas
3.13
liquid-cooled torch
torch cooled by the circulation of a cooling liquid
– 8 – 60974-7 IEC:2013
3.14
motorized torch
torch incorporating means to supply motion to the wire electrode
3.15
spool-on torch
motorized torch incorporating a filler wire supply
3.16
arc striking and stabilizing voltage
voltage superimposed on the welding circuit to initiate or maintain the arc or both
3.17
filler metal
metal added during welding or allied processes
[SOURCE: IEC 60050-851:2008, 851-14-43]
3.18
filler wire
filler metal in solid or tubular wire form which may or may not be part of the welding circuit
3.19
plasma tip
component that provides the constricting orifice through which the plasma arc passes
3.20
visual inspection
inspection by eye to verify that there are no apparent discrepancies with respect to the
provisions of the standard concerned
[SOURCE: IEC 60974-1:2012, 3.7]
3.21
plasma cutting system
combination of power source, torch, and associated safety devices for plasma cutting/gouging
3.22
plasma cutting power source
equipment for supplying current and voltage and having the required characteristics suitable
for plasma cutting/gouging and which may supply gas and cooling liquid
Note 1 to entry: A plasma cutting power source may also supply services to other equipment and auxiliaries, for
example auxiliary power, cooling liquid, and gas.
[SOURCE: IEC 60974-1:2012, 3.55]
3.23
torch coupling device
part of torch connecting the cable-hose assembly to the welding equipment
Note 1 to entry: A torch coupling device may include several connecting parts.
3.24
fume extraction torch
torch that incorporates means to capture the welding fumes
60974-7 IEC:2013 – 9 –
4 Environmental conditions
Torches shall be capable of operation when the following environmental conditions prevail:
a) range of ambient air temperature:
during operation: –10 °C to +40 °C;
b) relative humidity of the air:
up to 50 % at 40 °C;
up to 90 % at 20 °C.
Torches shall withstand storage and transport at an ambient air temperature of –20 °C to
+55 °C without any damage to function and performance.
NOTE Different environmental conditions may be agreed upon between the manufacturer and the purchaser.
Examples of these conditions are: high humidity, unusually corrosive fumes, steam, excessive oil vapour, abnormal
vibration or shock, excessive dust, severe weather conditions, unusual coastal or shipboard conditions, vermin
infestation and atmospheres conducive to the growth of mold.
5 Classification
5.1 General
Torches shall be classified in accordance with:
a) the process for which they are designed, see 5.2;
b) the method by which they are guided, see 5.3;
c) the type of cooling, see 5.4;
d) the method of striking the main arc for plasma processes, see 5.5.
5.2 Process
Torches can be designed for:
a) MIG/MAG welding;
b) self-shielded flux-cored arc welding;
c) TIG welding;
d) plasma welding;
e) submerged arc welding;
f) plasma cutting/gouging.
5.3 Guidance
Methods of torch guidance:
a) manual;
b) mechanical.
5.4 Cooling
Type of torch cooling method:
a) ambient air or shielding gas, see 3.12;
b) liquid, see 3.13.
– 10 – 60974-7 IEC:2013
5.5 Main arc striking for plasma processes
Methods for striking the main arc:
a) by an arc striking voltage;
b) by a pilot arc;
c) by contact.
6 Test conditions
6.1 General
All tests shall be carried out on the same new and completely assembled torch, fitted with the
cable-hose assembly normally supplied.
All tests shall be carried out at any ambient air temperature given in Clause 4, item a).
The accuracy of measuring instruments shall be:
a) electrical measuring instruments: class 1 (± 1 % of full-scale reading), except for the
measurement of insulation resistance and dielectric strength where the accuracy of the
instruments is not specified, but shall be taken into account for the measurement;
b) temperature measuring device: ± 2 K.
6.2 Type tests
All type tests given below shall be carried out on the same sample and in the following
sequence:
a) general visual inspection;
b) insulation resistance without humidity treatment (preliminary check), see 7.2;
c) impact resistance, see 11.1;
d) resistance to hot objects, see Clause 10;
e) protection against direct contact, see 7.4;
f) insulation resistance, see 7.2;
g) dielectric strength, see 7.3;
h) general visual inspection.
The heating test in accordance with 8.3 may be carried out on a separate sample and shall be
followed by the coolant leakage test in accordance with Clause 9. The other tests included in
this standard and not listed here may be carried out in any convenient sequence.
6.3 Routine tests
The following routine tests shall be carried out on each torch in the following sequence:
a) general visual inspection;
b) functional test as specified by the manufacturer, for example, leaks of fluid or gas, trigger
operation.
7 Protection against electric shock
7.1 Voltage rating
Torches shall be rated according to the classification and use as given in Table 1.
60974-7 IEC:2013 – 11 –
Table 1 – Voltage rating of torches
Voltage Insulation Dielectric Degree of protection in
rating resistance strength accordance with IEC 60529
V V r.m.s.
MΩ
peak
Classification
Nozzle Handle Torch Other
b, c
orifice coupling parts
a
device
Manually guided torches 113 1 1 000 IP0X IP3X IP2X IP3X
except for plasma
cutting
Mechanically guided 141 1 1 000 IP0X Not IPXX IP2X
torches except for applicable
plasma cutting and
submerged arc welding
Mechanically guided 141 1 1 000 IP0X Not IPXX IPXX
submerged arc welding applicable
torches
Manually guided plasma 500 2,5 2 100 Plasma IP4X IP3X IP3X
cutting torches tip, see
7.4.2
Mechanically guided 500 2,5 2 100 IP0X Not IP2X IP2X
plasma cutting torches applicable
a
Degree of protection for torch coupling device is tested while coupled.
b
Other parts are, for example, gas nozzle, neck.
c
Wire drive systems of motorized torches that are accessible to touch are not considered as other parts: IPXX.
7.2 Insulation resistance
The insulation resistance of a new torch shall, after the humidity treatment, be not less than
the values given in Table 1.
Conformity shall be checked by the following test:
a) Humidity treatment
A humidity cabinet is maintained at a temperature t between 20 °C and 30 °C and a
relative humidity between 91 % and 95 %.
The torch fitted with the cable-hose assembly (liquid-cooled torches without cooling liquid)
is brought to a temperature between t and (t + 4) °C and is then placed for 48 h in the
humidity cabinet.
b) Insulation resistance measurement
Immediately after the humidity treatment, the torch handle and 1 m at each end of the
cable-hose assembly are wiped clean and tightly wrapped in a metal foil covering the
external surface of the insulation.
The insulation resistance is measured by the application of a d.c. voltage of 500 V
between
– all circuits and the metal foil,
and
– all wires and circuits intended to be isolated from each other within the torch.
The reading is made after stabilization of the measurement.
– 12 – 60974-7 IEC:2013
7.3 Dielectric strength
7.3.1 General requirement
The insulation shall withstand the test voltages of Table 1 without any flashover or
breakdown.
The a.c. test voltage shall be of an approximate sine waveform with a peak value not
exceeding 1,45 times the voltage of Table 1, having a frequency of approximately 50 Hz or
60 Hz. Alternatively, a d.c. test voltage of 1,4 times the r.m.s. test voltage may be used.
Conformity shall be checked by the following test:
Liquid-cooled torches are tested without cooling liquid.
The handles are tightly wrapped with a metal foil. The cable-hose assembly is placed in
contact with a conductive surface throughout its entire length, for example wrapped around a
metal cylinder or coiled on a flat metal surface. The metal foil and the conductive surface are
electrically connected.
The full value of the test voltage is applied for 60 s between:
a) the conductive surface and each isolated circuit;
b) all circuits intended to be isolated from each other (e.g. trigger or other remote control
circuits).
At the discretion of the manufacturer, the test voltage may be slowly raised to the full value.
The maximum permissible setting of the overload release shall be 100 mA. The high-voltage
transformer shall deliver the prescribed voltage up to the tripping current. Tripping of the
overload release is regarded as a failure.
7.3.2 Additional requirements for plasma cutting torches
In addition for manual plasma cutting torches the insulation between the handle and the
cutting circuit shall withstand a test voltage of 3 750 V r.m.s. During the dielectric strength
test of plasma cutting torches, the electrode and plasma tip connections should be electrically
connected together.
Conformity shall be checked by the test given in 7.3.1.
7.3.3 Additional requirements for striking and stabilizing voltage rating
Torches intended for use with arc striking and stabilizing devices shall have an arc striking
and stabilizing voltage rating.
For tungsten inert gas (TIG) and plasma arc welding torches the rated arc striking and/or
stabilizing voltage shall be determined by the manufacturer.
For plasma cutting torches, the rated arc striking and/or stabilizing voltage shall be
determined as follows:
a) operate each power source expected to form a safe system (see item o) of Clause 13)
according to manufacturer's recommendation, for example with proper consumables and
gasses, and under single fault condition;
b) measure the arc striking and/or stabilizing voltage at each end of the torch;
c) the highest value measured, from all power sources operated in item a), will be the rated
arc striking and/or stabilizing voltage.
60974-7 IEC:2013 – 13 –
The torch insulation shall withstand a test voltage without flashover or breakdown. Corona
discharges are permitted.
Liquid-cooled torches may be tested without cooling liquid.
Conformity shall be checked by the following test:
The torch handle is tightly wrapped with a metal foil. The cable and hose assembly is placed
in contact with a conductive surface throughout its entire length, for example wrapped around
a metal cylinder or coiled on a flat metal surface. The metal foil and the conductive surface
are electrically connected.
A test voltage with a peak voltage 20 % higher than the rated arc striking and stabilizing
voltage is applied for 2 s between the torch electrode and the conductive surface, and
between the torch electrode and other isolated circuits. This test voltage is either:
a) high-frequency voltage of pulse width between 0,2 µs and 8 µs, with a repetition frequency
between 50 Hz and 300 Hz; or
b) an a.c. voltage of approximately sine waveform at 50 Hz or 60 Hz.
7.4 Protection against electric shock in normal service (direct contact)
7.4.1 Degree of protection requirements
Torches shall meet the degree of protection requirements of Table 1. In addition cable-hose
assembly shall meet the degree of protection IP 3X. Torches are not intended for operation
during rain or snow or equivalent conditions.
Conformity shall be checked in accordance with IEC 60529.
7.4.2 Additional requirements for plasma cutting torches
The plasma cutting torch, parts (e.g. parts typically replaced due to wear) and plasma cutting
power source, recommended by the manufacturer, shall form a safe system.
Additional requirements for plasma cutting torches are given in 6.3.4 of IEC 60974-1:2012.
8 Thermal rating
8.1 General
Manual torches shall be rated at a minimum of 100 % or 60 % or 35 % duty cycle.
Mechanically guided torches shall be rated at a minimum of 100 % duty cycle.
Fume extraction torch shall be rated at the extraction flow rate defined by the manufacturer.
8.2 Temperature rise
The temperature rise of manual torches, at any point on the outer surface of the part of the
handle gripped by the operator, shall not exceed 30 K.
The temperature rise of cable-hose assembly, at any point on the outer surface, shall not
exceed 40 K.
After completion of the tests, the safety and operability of the torch shall not be impaired.
– 14 – 60974-7 IEC:2013
Conformity shall be checked by the heating test according to 8.3.
8.3 Heating test
8.3.1 General
The torches shall be loaded with all rated currents at their corresponding rated duty cycles,
see 8.1.
The mean value of the d.c. current shall be taken and the electrode polarity shall be chosen in
accordance with 8.3.2 and 8.3.3.
The temperature shall be measured at the hottest spot on the area of the handle, normally
gripped by the operator for manual torches.
The temperature shall be measured at the hottest spot of cable-hose assembly.
The temperature measuring device(s), handle and cable-hose assembly shall be protected
from draughts and radiant heat.
The torch clamping device used shall not significantly affect the test result, for example by
heat loss.
Liquid-cooled torches shall be continuously cooled with the minimum flow rate and minimum
cooling power as specified by the manufacturer (see item h) of Clause 13).
NOTE Cooling power is defined in IEC 60974-2.
Each heating test shall be carried out for a period of not less than 30 min and continued until
the rate of temperature rise does not exceed 2 K/h.
The cycle time for test purposes shall be 10 min.
The ambient and torch temperature shall be measured simultaneously during the last 10 min
in the case of continuous load (100 % duty cycle). For lower duty cycles, it shall be measured
in the middle of the load period during the last cycle.
The ambient air temperature is measured by a device, located at a distance of 2 m, at the
same height as the torch and shall be protected from draughts and radiant heat.
8.3.2 Metal inert/active gas (MIG/MAG) or self-shielded flux-cored arc welding torch
A metal tube of a diameter and length appropriate to the welding process, for example
400 mm in diameter and 500 mm long, is horizontally clamped into a rotating device. The
inside of the tube is cooled by means of water.
The torch shall be positioned in a plane perpendicular to the tube axis in such a way that the
wire electrode is 15 ° to the vertical (see Figure B.1). In addition, for manually guided
−15
torches, the handle shall be positioned on the cooler side.
The torch shall be moved parallel to the centre line of the tube in order to form a weld bead.
a) Test conditions for metal inert gas arc welding (MIG) of aluminium alloys are given below
and in Table 2:
– wire electrode: aluminium, 3 % to 5 % magnesium;
– type of current: d.c.;
60974-7 IEC:2013 – 15 –
– electrode polarity: positive;
– shielding gas: argon;
– tube material: aluminium alloy;
– load voltage and welding speed: adjusted to give a stable arc and a continuous
weld pool.
Table 2 – Test values for metal inert gas arc welding (MIG) of aluminium alloys
Welding current Nominal diameter Distance between contact Maximum gas flow
of the wire electrode
tip and metal tube ±20 %
A mm mm l/min
Up to 150 0,8 10 10
151 to 200 1 15 12
201 to 300 1,2 18 15
301 to 350 1,6 22 18
351 to 500 2 26 20
Above 500 2,4 28 20
b) Test conditions for metal active gas arc welding (MAG) of mild steel are given below and
in Table 3:
– wire electrode: copper-coated mild (low carbon) steel;
– type of current: d.c.;
– electrode polarity: positive;
– shielding gas: argon/CO mixed gas (15 % to 25 % CO );
2 2
– tube material: mild (low carbon) steel;
– load voltage and welding speed: adjusted to give a stable arc and a continuous
weld pool.
If additional values for the shielding gas CO are specified in the instructions for use, an
additional test with this gas shall be carried out according to the test conditions given in
Table 3.
Table 3 – Test values for metal active gas arc welding (MAG) of mild steel
Welding Nominal diameter of the Distance between contact Maximum gas flow
current wire electrode tip and metal tube ±20 %
A mm mm l/min
Up to 150 0,8 10 10
151 to 250 1 15 13
251 to 350 1,2 18 15
351 to 500 1,6 22 20
Above 500 2 26 25
c) Test conditions for metal active gas arc welding (MAG) with flux-cored wire are given
below and in Table 4:
– wire electrode: rutile type;
– type of current: d.c.;
– electrode polarity: positive;
– shielding gas: argon/CO mixed gas (15 % to 25 % CO );
2 2
– 16 – 60974-7 IEC:2013
– tube material: mild (low carbon) steel;
– load voltage and welding speed: adjusted to give a stable arc and a continuous
weld pool.
Table 4 – Test values for metal active gas arc welding (MAG) with flux-cored wire
Welding Nominal diameter Distance between contact Maximum gas
current of the wire electrode flow
tip and metal tube ±20 %
A mm mm l/min
251 to 350 1,2 to 1,4 25 15
351 to 500 1,6 to 2 30 18
Above 500 2,4 35 20
d) Test conditions for self-shielded flux-cored arc welding of mild steel are given below and
in Table 5:
– wire electrode: type 1: a wire designed with a fast freezing slag
for all-positional welding;
type 2: a wire designed for high deposition rates
in flat and horizontal vertical position welding;
– type of current: d.c.;
– electrode polarity: wire electrode type 1: negative;
wire electrode type 2: positive;
– tube material: mild (low carbon) steel;
– load voltage and welding speed: adjusted to give a stable arc and a continuous
weld pool.
Table 5 – Test values for self-shielded flux-cored arc welding of mild steel
Welding Type of wire electrode Nominal diameter Distance between contact
current of the electrode
tip and metal tube ±20 %
A mm mm
Up to 250 1 Up to 1,2 20
251 to 350 2 1,6 to 2,0 50
351 to 500 2 2,4 to 3,0 50
Above 500 2 3,2 and more 60
8.3.3 Tungsten inert gas (TIG) and plasma arc welding torch
A copper block, with or without water cooling (see for example, Annex C), shall be used and
the torch shall be positioned perpendicular to the upper horizontal face of the copper block
(see Figures B.2 and B.3).
For plasma welding torches, the shielding gas and the gas flow shall be as specified by the
manufacturer in the instructions for use.
The testing installation shall be equipped with the instruments as shown in Figure A.5.
The nominal a.c. welding currents of a torch are defined as 70 % of the nominal d.c. value.
a) Test conditions for tungsten inert gas arc welding (TIG) are given below and in Table 6:
– electrode type: tungsten alloy;
60974-7 IEC:2013 – 17 –
– electrode diameter: maximum for the test current as recommended by
the manufacturer;
– type of current: d.c.;
– electrode polarity: negative;
– shielding gas: argon;
– load voltage: adjusted to give a stable arc and a continuous
weld pool.
Table 6 – Test values for tungsten inert gas arc welding (TIG)
Welding current Maximum gas flow Distance between nozzle Distance between
and copper block ±1 mm electrode and copper
block ±1 mm
A l/min mm mm
Up to 150 7 8 3
151 to 250 9 10 5
251 to 350 11 10 5
351 to 500 13 10 5
Above 500 15 10 5
b) Test conditions for plasma welding are given below and in Table 7:
– type of current: d.c.;
– electrode polarity: negative;
– gases and gas flow: as specified by the manufacturer.
Table 7 – Test values for plasma arc welding
Welding current Distance between plasma tip and
copper block ±1 mm
A mm
Up to 30 3
31 to 50 3
51 to 100 3
101 to 150 4
151 to 200 6
201 to 250 8
251 to 280 8
Above 280 10
8.3.4 Plasma cutting torch
The torch shall be tested:
a) at the rated current with the corresponding rated duty cycle, see 8.1;
b) with the type of gas and flow rate specified by the manufacturer;
and
c) at the distance between plasma tip and workpiece specified by the manufacturer with one
of the following test arrangements:
– 18 – 60974-7 IEC:2013
1) copper block with a hole, according to Annex D or similar (suitable for use up to 75 A):
the torch shall be positioned perpendicularly to the upper horizontal face of the copper
block and centred to the hole;
2) copper bars with a slot, according to Annex E or similar (suitable for use up to 200 A):
the torch shall be positioned perpendicularly to the upper horizontal face of the copper
bars, centred between them and moved about 500 mm backwards and forwards;
3) cutting (suitable for all currents): the torch shall be positioned perpendicularly to a mild
steel sheet or tube
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