TWI Frequently asked questions
Standards commonly used in the UK joining industry: Welding Equipment
AWS A10.1M: 2007
Specification for calibration and performance testing of secondary current sensing coils and weld current monitors used in single phase AC resistance welding
Methods for testing and describing the performance of Rogowski-type air core current sensing coils (CSC) and weld current monitors (WCM) used in the measurement of single-phase ac resistance welding currents are specified. Relevant terms are defined. CSC and system tests and calibration methods are detailed and user information is prescribed.
AWS C2.21M/C2.21: 2003
Specification for thermal spraying equipment. Acceptance inspection
The requirements for acceptance inspection of plasma; flame powder, wire, rod and cord; wire arc; high velocity oxygen fuel type machines are specified.
AWS C4.3/C4.3M 2007
Recommended practices for safe oxyfuel gas heating torch operation
The latest procedures and safety requirements for oxyfuel gas heating torch operation are presented.
AWS D8.6: 2005
Specification for automotive resistance spot welding electrodes
The standard outlines the requirements for resistance spot welding electrodes as used in the automotive industry. The various types are defined, and dimensions and specifications given. With the exception of face materials, only copper alloys are considered. An identification system is given. Numerous figures include dimensions in tabular form. An appendix gives examples of commercially available types.
BS 638
Arc welding power sources, equipment and accessories
Part 1: 1979 Specification for oil cooled power sources for manual, semi-automatic and automatic metal arc welding and for TIG welding
Superseded by BS 638:Part 10
Part 2: 1979 Specification for manual metal arc welding with covered electrodes and for TIG welding
Superseded by BS 638:Part 10
Part 3: 1979 Specification for air cooled power sources for semi-automatic and automatic metal arc welding
Superseded by BS 638:Part 10
Part 4: 1996 Specification for welding cables
Requirements are specified for single core flexible cables carrying welding current in arc welding circuits. Designations, composition and form of the conductor, nature of the covering, construction, marking and testing are specified for cables rated at 100 V AC rms and up to 450 V AC rms.
Part 5: 1988 Specification for accessories
Partially superseded by BS EN 60974-5:2002 and BS EN 60974-12:1996
This part of BS 638 specifies requirements for accessories intended for use in arc welding. Types of accessories covered include those associated with power sources (power factor correction capacitors, coupling devices, distribution boxes, parallelling devices, return current clamps, arc initiating and maintaining devices); heating and drying accessories (electrode heating quivers, electrode dry and/or storage ovens); wire drive feed units and associated accessories (wire reels and spools, water recirculating units); gas accessories (pressure regulators, welding hoses and hose connections); safety accessories (screens, radiation filters, protective clothing, dust masks and respirators, fume extractors, curtains and screens); wire brushes and chipping hammers.
Part 6: 1984 Specification for safety requirements for construction
Superseded by BS 638:Part 10
Part 7: 1984 Specification for safety requirements for installation and use
Superseded by DD CLC/TS 62081
Part 8: 1984 Specification for electrode holders and hand held torches and guns for MIG, MAG, and TIG welding
Superseded by BS EN 50078:1994 and BS EN 60974-11:1996
Part 9: 1990 Specification for power sources for manual arc welding with limited duty
Superseded by BS EN 60974-6:2003
Part 10: 1990 Specification for safety requirements for arc welding equipment: welding power sources
Superseded by BS EN 60974-1:1998
BS 7570: 2000
Code of practice for validation of arc welding equipment
Validation methods are recommended for welding equipment constructed in accordance with BS EN 60974-1 or equivalent. This covers welding power sources, wire feeders, welding instrumentation and ancillary equipment (flow gauges, thermocouples, robots, manipulators) which may affect weld quality. Aspects covered include execution of validation procedures; validation techniques (instrumentation, power loading, measurement procedures); and validation certification. Annexes cover special considerations for high precision equipment and for process variants.
BS 8451: 2004
Rubber hoses for gas welding, cutting and allied processes. High kink resistant heavy duty welding hose (type H). Specification
Requirements for two classes of flexible rubber hose for use up to a maximum working pressure of 20 bar over a temperature range of -25°C to +70°C are specified. Type H hoses are mainly used in long lengths in the construction and military sectors.
BS EN 559: 2003
Gas welding equipment. Rubber hoses for welding, cutting and applied processes.
Requirements are presented for rubber hoses for welding, cutting and allied processes, particularly heating, brazing and metallisation (spraying). The hoses in question may convey fuel gases, oxygen, compressed air or shielding gases. Materials, dimensions, physical properties, colours and marking are specified.
BS EN 560: 2005
Gas welding equipment. Hose connections for equipment for welding, cutting and allied processes
The dimensions and characteristics of the constituent parts of hose connections, e.g. pressure regulators according to EN ISO 2503 and blow pipes, are specified. The design of the part of the hose tail inserted into the hose is not covered; this is specified in EN 1256.
BS EN 561: 2002
Gas welding equipment. Quick-action coupling with shut-off valves for welding, cutting and allied processes
Specifications and type tests are defined for quick-action couplings and shut-off valves as used in equipment for gas welding, cutting and allied processes to connect the hoses between the regulator and the torch.
BS EN 730
Gas welding equipment
Part 1: 2002 Incorporating a flame (flashback) arrestor
General requirements and tests for fuel gas, oxygen or compressed air safety devices incorporating a flame (flashback) arrestor for use downstream of the manifold, cylinder and/or pipeline outlet regulators, and upstream of blowpipes are specified. Location of the devices in the gas system is not specified. The use of safety devices with flashback arrestors for use with premixed oxy/fuel or air/fuel gas supply systems (downstream of a gas mixer or generator, for example) is not covered.
Part 2: 2002 Safety devices not incorporating a flame (flashback) arrestor
General requirements and tests for fuel gas, oxygen or compressed air safety devices not incorporating a flame (flashback) arrestor for use downstream of the manifold, cylinder and/or pipeline outlet regulators, and upstream of blowpipes are specified. Location of the devices in the gas system is not specified.
BS EN 1256: 2006
Gas welding equipment. Specification for hose assemblies for equipment for welding, cutting and allied processes
The standard specifies performance and test requirements of hose assemblies (hose tails and clamps) using rubber hose, if supplied in assembled condition for equipment for gas welding, cutting and allied processes. It does not apply to assemblies upstream of the regulators. The tests prescribed are for type test or quality control checks only, and cover gas tightness, and resistance to separation under pressure or axial load.
BS EN 13705: 2004
Welding of thermoplastics. Machines and equipment for hot gas welding (including extrusion welding)
This Standard specifies general performance requirements for machines and equipment for the hot gas (including extrusion) welding of semi-finished products made from thermoplastics. General requirements are given on marking, documentation and nozzles. Hot gas welding requirements cover the design, construction and performance of manual welding equipment and accessories. Extrusion welding requirements are given for the plastification and preheating systems, the welding head and shoe and for the pressing tools; automatic shut down is also dealt with.
BS EN 13918: 2003
Gas welding equipment. Integrated flowmeter regulators used on cylinders for welding, cutting and applied processes. Classification
This standard specifies the requirements, classification and type tests for integrated flow meter regulators used on gas cylinders for welding cutting and allied processes for compressed gases up to 300 bar (30 MPa) and for CO2. It covers requirements for materials, design, type test procedure (test conditions, leakage, stability, accuracy and classification, mechanical resistance, relief valve performance and ignition in integrated flow meter regulators for oxygen), marking and instructions for use. Information is given on integrated flow meter regulator operating principles and flow measurement test apparatus.
BS EN 15339
Thermal spraying. Safety requirements for thermal spraying equipment
Part 2: 2007 Gas control units
This standard specifies safety requirements of gas control units for thermal spraying.
BS EN 50078: 1994
Torches and guns for arc welding
Superseded by BS EN 60974-7:2000; partially supersedes BS 638:Part 8:1994
BS EN 50199: 1996
Electromagnetic compatibility (EMC). Product standard for arc welding equipment
Superseded by BS EN 60974-10:2003
BS EN 60974
Arc welding equipment
Part 1: 2005 Welding power sources
Supersedes BS 638-10:1990; identical to IEC 60974-1
This standard can be applied to welding power sources for arc welding and allied processes, such as electric arc cutting and arc spraying. Safety requirements for construction and performance requirements of welding power sources are specified.
Part 2: 2007 Liquid cooling systems
Identical to IEC 60974-2
This standard specifies safety and construction requirements for liquid cooling systems intended to cool arc welding torches. The cooling systems can be internal or external to power sources for arc welding and allied processes. The standard is not applicable to refrigerated cooling systems. Clauses cover environmental conditions, test conditions, protection against electric shock, mechanical requirements, cooling system and cooling power requirements, rating plate specifications, documentation and marking.
Part 3: 2007 Arc striking and stabilising devices
Identical to IEC 60974-3
This British Standard implements the equivalent European and International Standards (EN 60974-3: 2003 and IEC 60974-3: 2003) and specifies safety requirements for arc striking and stabilising devices used in arc welding and allied processes such as plasma cutting and arc spraying. The devices may be stand alone units or housed within the welding power source enclosure. Electromagnetic compatibility (EMC) requirements are excluded. Requirements cover test conditions, protection against electric shock, thermal requirements, abnormal operation, thermal protection, input supply connection, output, control circuits, and mechanical, rating plate, instructions and markings requirements.
Part 4: 2007 In service inspection and testing
Identical to IEC 60974-4
Test procedures are specified for in-service inspection and, after repair, to ensure electrical safety. These test procedures are also applicable for maintenance. The standard is applicable to power sources together with ancillary equipment for arc welding, cutting and allied processes built in conformity with IEC 60974-1. It is not applicable to testing of new power sources or engine-driven power sources.
Part 5: 2007 Wire feeders
Partially replaces BS 638-5:1988; identical to IEC 60974-5
Safety and performance requirements for wire feed systems for industrial and professional equipment used for arc welding (manual or mechanically guided torches) are specified. Stand-alone units which may be connected to a separate power source, or where the power source and wire feed unit are housed in a single enclosure are covered.
Part 6: 2003 Limited duty manual metal arc welding power sources
Supersedes BS 638-9:1990; identical to IEC 60974-6
Applicable to power sources with a thermal cut-out device for use in manual metal arc welding with limited duty. Safety requirements for construction and performance requirements, limited to 160 A maximum welding current are specified. The standard is not applicable to rotating,or remotely controlled power sources or those incorporating frequency conversion.
Part 7: 2005 Torches
Supersedes BS EN 50078:1994; identical to IEC 60974-7
This standard specifies safety and construction requirements for torches for arc welding (MIG/MAG, FCA, TIG, plasma, submerged arc) and allied processes. It is not applicable to electrode holders for manual metal arc welding or torches for air-arc cutting or gouging. Clauses cover environmental conditions, classification, test conditions, protection against electric shock, thermal rating, pressure of the cooling liquid system, resistance to hot objects, impact resistance, marking and instructions for use.
Part 8: 2004 Gas consoles for welding and plasma cutting systems
Identical to IEC 60974-8
Safety and performance requirements for gas consoles for use with combustible gases or oxygen are specified. The consoles are designed to supply gas for arc welding, plasma cutting, gouging and allied processes in a non-explosive atmosphere, and can be external or internal to the power source enclosure. The latter are also regulated by this standard.
Part 10: 2007 Electromagnetic compatibility (EMC) requirements
Supersedes BS EN 50199:1996; identical to IEC 60974-10
Applicable to all equipment for arc welding and allied processes (power sources, wire feeders, liquid cooling systems, arc striking and stabilising devices, etc.). Equipment type tested in accordance with, and meeting the requirements of, this standard is considered to be in compliance for all applications.
Part 11: 2004 Electrode holders
Supersedes BS 638: Part 8: 1994; identical to IEC 60974-11
This standard covers electrode holders for MMA welding with electrodes up to 10 mm diameter, excluding those for underwater welding. Requirements specified include designation of current rating, operation, insulation resistance and electric shock protection, thermal rating with resistance to heat or weld spatter, welding cable connection and impact resistance, marking and operating instruction requirements. It is applicable to environments up to 40 deg.C and 90% humidity at 20 deg.C.
Part 12: 2005 Coupling devices for welding cables
Partially supersedes BS 638-5:1988; identical to IEC 60974-12
Requirements are presented for coupling devices for flexible welding cables which are designed to be connected and disconnected manually without the use of tools. Tests, and electrical, thermal and mechanical properties required are outlined.
BS EN ISO 2503: 1998
Gas welding equipment. Pressure regulators for gas cylinders used in welding, cutting and allied processes up to 300 bar
Supersedes BS EN 585:1995
Requirements for single or two-stage pressure regulators for connection to gas cylinders containing compressed gases up to 300 bar are specified. The gases covered are dissolved acetylene; liquefied petroleum gases (LPG); methylacetylene-propadiene-mixtures (MPS) and carbon dioxide (CO 2 ) used in welding, cutting and allied processes. The standard covers units of measurement; manufacturing requirements; types of connections; physical characteristics such as pressures and flow rates; marking; instructions for use and type test procedures.
BS EN ISO 5172: 2006
Gas welding equipment. Blowpipes for gas welding, heating and cutting. Specifications and tests
The standard specifies the characteristics of manual (not air aspirated) blowpipes for gas welding, cutting and heating of metals, and gives specifications and corresponding tests. It specifies hose connections, material, marking, safety and operational requirements, and test conditions for leaks, sustained backfire, overheating, stability in wind, valve endurance, and backflow.
BS EN ISO 5183
Resistance spot welding. Electrode adaptors, male taper 1:10
Part 1: 2001 Conical fixing, taper 1:10
Supersedes BS EN 25183-1:1992
Dimensions, tolerances and materials are specified for resistance spot welding electrode adaptors where the fixing part for the electrode cap is a male taper and for which the electrode taper fits conform to standard ISO 1089.
Part 2: 2001 Parallel shank fixing for end-thrust electrodes.
Supersedes BS EN 25183-2:1992
Dimensions, tolerances, designation, materials and marking are specified for resistance spot welding electrodes where the fixing part for the electrode cap has a male taper and a parallel shaft is used to fix the adaptor to the electrode holder.
BS EN ISO 5826: 2003
Resistance welding equipment. Transformers. General specifications applicable to all transformers
Supersedes BS 7125:1989
This standard specifies safety, construction and test requirements applicable to transformers for resistance welding equipment without a connected rectifier. Requirements are given for physical environment, operating and test conditions, protection against electric shock, thermal specification, rated no-load output voltage, rated short-circuit voltage, cooling liquid circuit, dynamic behaviour, rating plate and instructions.
BS EN ISO 7291: 2001
Gas welding equipment. Pressure regulators for manifold systems used in welding, cutting and allied processes up to 300 bar
Supersedes BS EN 961:1996
This standard specifies requirements and test methods for pressure regulators in manifold systems normally used for compressed gases up to 300 bar (30 MPa) for welding, cutting and allied processes. Gases included are: dissolved acetylene, methylacetylene-propadiene-mixtures (MPS) and carbon dioxide (CO 2 ). It covers regulation of the pressure at the outlet of high-pressure lines from manifold gas cylinders.
BS EN ISO 13918: 1998
Welding. Studs and ceramic ferrules for arc stud welding
The most important dimensions of studs and ceramic ferrules for arc stud welding are specified for customary applications. Further types may be specified as required for special application.
BS EN ISO 17662: 2005
Welding. Calibration, verification and validation of equipment used for welding, including ancillary activities
Requirements are specified for the calibration, verification and validation of equipment used for: control of process variables during fabrication, or control of the properties of equipment used for welding or allied processes, where the resulting output cannot be readily or economically documented by subsequent monitoring, inspection and testing. This is relevant to process variables influencing fitness-for-purpose and in particular the safety of the fabricated product.
BS ISO 22829: 2007
Resistance welding. Transformer rectifier for welding guns with integrated transformers. Transformer rectifier units operating at 1000 Hz frequency
This International Standard is applicable to transformer-rectifier units as used in electric resistance welding machines operating from a power supply with a frequency of 1 000 Hz, and of a rated value of the input voltage equal to or higher than 500 V. These transformer-rectifier units are primarily used in welding guns with an integrated transformer. For these transformer units, this International Standard supplements the requirements given in ISO 5826 and ISO 10656, which remain applicable except where amended by this International Standard.
DD CLC/TS 62081: 2002
Arc welding equipment installation and use
Identical to IEC 62081:1999; Supersedes BS 638:Part 7
Applicable to the installation and industrial and professional use of welding power sources, equipment and accessories for arc welding and allied processes.
IEC 62135
Resistance welding equipment
Part 1 Safety requirements for design, manufacture and installation
Part 2 Electromagnetic compatibility (EMC) requirements
ISO 5182: 2008
Resistance welding. Materials for electrodes and ancillary equipment
Will be implemented as an identical British Standard
ISO 9012: 2008
Gas welding equipment. Air-aspirated hand blowpipes. Specifications and tests
Will not be implemented as a British Standard