Welding, Cutting and Allied Processes

Welding, brazing and cutting are essential processes in the manufacturing industry. All these processes depend crucially on industrial gases.

BCGA is committed to ensuring SAFE use of industrial gases in these processes and produces several useful documents, as detailed below, which Employers and their operatives should be familiar with. At each workplace where welding cutting and other allied process are in-use a suitable and sufficient risk assessment shall be carried out and, as necessary, appropriate controls put in place. BCGA TIS 15 provides information on the potential hazards (associated with gases) and possible controls.

When used correctly, gases are safe. Gases have hazards and their storage, handling and use should be included in your risk management process for controlling health and safety risks in the workplace. Each gas has its own hazardous properties, which may include being flammable, being asphyxiant and, for oxygen, the hazards from enrichment. BCGA GN 11 identifies potential hazards from the escape, leak or accumulation of gases into the workplace and the associated risks.

Hazards & Safety

There are additional hazards associated with welding and hot cutting processes, including from the fluxes and materials used. The hazards include excessive heat, exposure to bright direct and reflected light, including ultraviolet light, and the inhalation of welding fume, such as airborne gases and very fine particles. All activities should only be carried out by competent people and must be subject to risk assessment with suitable controls. Controls such as:

Local exhaust ventilation (LEV), including regular maintenance and the use of visual indicators;
Health surveillance, including biological monitoring and personal air sampling;
Personal protective equipment, including respiratory protective equipment.

The risk assessment should also take into consideration others who may be in the vicinity.

BCGA has engaged with the Health Safety Executive (HSE) and others via the Welding Fume Health Partnership to try to influence attitudes and behaviours with respect to welding fume, particularly in encouraging the use of appropriate controls and the safety of those involved.

The HSE provide guidance for the Control of Substances Hazardous to Health (COSHH) for welding and specific guidance on managing welding fume. BCGA supports the Chartered Society for Worker Health Protection (BOHS) and its ‘Breathe Freely’ campaign to control exposure to hazardous substances, such as welding fume, and to prevent occupational lung disease in the construction industry.  Lots more information is available on their website – www.breathefreely.org.uk. BCGA SA 03 highlights the hazards from welding fume.

Fuel gases are mostly hydrocarbon based and each has its own unique properties. The choice of a fuel gas is based on its ability to burn in air or oxygen and will be dependent on the specific requirements of the job, as well as the location at which it is being used. There are several useful fuel gases of which acetylene and propane are the most common. For information on these refer to BCGA TIS 32. Following a major review of legislation in 2014, acetylene was placed under The Acetylene Safety (England and Wales and Scotland) Regulations. These Regulations require that all mobile systems shall be fitted with a purpose designed regulator for acetylene, a flashback arrestor incorporating a non-return valve and a pressure and/or temperature sensitive cut-off valve.

HSE provide information on the safe use of acetylene on their website and publish INDG 327Working safely with acetylene.

Brazing requires that the work be heated to the correct temperature for the process to take place. There are several different methods for achieving this heating, but the use of an oxygen / fuel gas burner is the most common. Typically, either oxygen / acetylene or oxygen / propane are used, with the higher temperature of the oxygen / acetylene flame giving maximum flexibility. BCGA CP 7 defines how to design, operate and maintain portable and mobile systems for oxygen / fuel gas processes. Fixed installations, which supply gas through a control and distribution system, are specified in BCGA CP 4 and, for acetylene, BCGA CP 6.

Cutting of metals is often carried out using oxygen / fuel gas equipment. The process consists of heating the work using the flame, and then using excess oxygen to burn the metal. Depending on the scale of the job either oxygen / acetylene or oxygen / propane systems can be used. As appropriate refer to BCGA CP 4BCGA CP 6 and BCGA CP 7.

There are several options when welding, including gas, electric arc, metal inert gas (MIG), tungsten inert gas (TIG), etc. For gas welding of ferrous metals the flame temperature must be the highest possible to get the metal to melting point. Thus only oxygen / acetylene is suitable for this process. Modern electric arc welding requires the use of shielding gas to protect the weld from the atmosphere. Sometimes this shielding gas is a single gas, very often argon, but the use of gas mixtures is increasingly common, with mixtures tailor-made according to the metal being welded.

Welding, cutting and allied processes are well supported by published standards, which are increasingly either European (EN) or International (ISO). BCGA is very active within BSI in the development of these standards, via the Welding Committee WEE/18.

All gas equipment must be suitable for the purpose for which it is provided, be safe to operate, and be subject to regular inspection and maintenance. BCGA CP 7 sets out the requirement for carrying out assembly checks, before and after use checks, and a periodic thorough inspection. Guidance on carrying out a thorough inspection is provided in BCGA GN 44 and BCGA TIS 18 provides information to assist in identifying the inspection and replacement date markings on certain items.

Committees

Within BCGA, welding, cutting and allied processes are the responsibility of Technical Sub-Committee (TSC) 3. Members can access information on TSC3 via the Committee Meetings page.

Publications

Publications

CP4 Gas supply and distribution systems (excluding acetylene) Revision 5: 2020

305 Codes of Practice CP4

Provides the minimum safety practices and principles for the selection and assembly of pressure equipment to control and distribute gases. Details the requirements for the design, installation, testing, commissioning and handover of a pressure system. It sets out the roles and responsibilities of the Designer, the Installer and the User.

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CP5 The design and construction of manifolds using acetylene gas from 1.5 to 25 bar Revision 3: 2016

308 Codes of Practice CP5

Covers the design and construction of acetylene gas manifolds, working at pressures from 1.5 bar up to 25 bar, to which single or multiple cylinders can be connected. The statutory requirements in such systems are detailed.

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CP6 The safe distribution of acetylene in the pressure range 0 – 1.5 bar Revision 3: 2015

309 Codes of Practice CP6

Gives guidance on the safe distribution of acetylene at pressures between 0-1.5 bar. Both fixed and mobile systems are included, as are the statutory requirements.

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CP7 The safe use of oxy-fuel gas equipment (individual portable or mobile cylinder supply) Revision 8: 2018

307 Codes of Practice CP7

Provides the minimum safety standards required for the assembly, examination, inspection, maintenance and use of individual portable or mobile cylinder oxy-fuel gas equipment, each gas being supplied from a cylinder and individually controlled by a cylinder-mounted pressure regulator.

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GN11 The management of risk when using gases in enclosed workplaces. Revision 4: 2018

1825 Guidance Notes GN11

Provides guidance that can be used in the assessment of risk associated with gases in enclosed workplaces, to help identify where hazardous atmospheres may occur and to advise on control measures that may be appropriate.

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GN44 Portable or mobile cylinder gas equipment. Thorough inspection. 2021

2556 Guidance Notes GN44

Provides guidance to enable a thorough inspection, which must be carried out on portable or mobile cylinder gas equipment at suitable intervals by a competent independent safety inspector.

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TIS15 Model risk assessment for the storage and use of gas cylinders for oxy-fuel applications. Revision 1: 2015

1965 Technical Information Sheets TIS15

This document lays out a model risk assessment. Included are a series of tabulated risk assessment sheets which address the main aspects of the storage, transportation and use of oxygen / fuel cylinders. A copy is also provided in a format that allows the user to modify the contents to suit their specific needs.

Where this document is downloaded as an Excel Spreadsheet, the user has the option of amending the contents and, as such, it is beyond the direct control of the BCGA. In this situation, the user takes full responsibility for the contents of the document.

Please see the TIS 15 below to download the amendable Excel Spreadsheet.

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TIS18 Date marking of gas accessories. Revision 3: 2018

1974 Technical Information Sheets TIS18

Manufacturers & suppliers use various systems to identify the date at which certain items will require replacement or refurbishment. This document identifies the marking system employed by some BCGA members.

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TIS29 Oxy-fuel gas equipment. Selection and assembly. 2018

1998 Technical Information Sheets TIS29

A summary of the requirements for selecting and assembling oxy-fuel gas equipment which supports the requirements of BCGA Code of Practice 7.

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TIS32 Acetylene or propane (for welding, cutting and allied processes). Revision 2: 2019

2004 Technical Information Sheets TIS32

This document provides technical information on the different properties of acetylene and propane to help the user make an informed choice when choosing a fuel gas for welding, cutting and allied processes.

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SA1 The hazards of using incompatible regulators with acetylene. Revision 1: 2021

1864 Safety Alerts SA1

Incidents have occurred where unsuitable regulators have been used with acetylene gas. This has the potential to cause an explosion due to incorrect pressure or incompatible materials. This Safety Alert highlights the problem and provides advice on choosing a correct regulator.

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SA2 Hydrogen and oxygen flames generated from electrolysis of water – Safety devices: 2019

1866 Safety Alerts SA2

Equipment designed to generate gases, which results in a flammable gas mixture being created for the purpose of being ignited, is required to have appropriate safety devices fitted to protect the gas source and to provide safety for the operator. This Safety Alert highlights the requirements for the fitting of a suitable flame arrestor.

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SA3 Welding fumes: 2021

2557 Safety Alerts SA3

Highlights the hazards from welding fume. It explains the hazard and recommends safe behavior through identifying suitable safety information, appropriate engineering controls and the use of personal protective equipment to manage any residual risk.

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