CEN/TC 121/WG 19 - Equipment for gas welding, cutting and allied processes

This document, together with EN 746-1, EN 746-2 and EN 746-11, specifies the safety requirements for industrial thermoprocessing equipment ( IThE) with "Open firing oxy-fuel gas welding equipment", as well as the relevant gas distribution and protective systems. This document applies to IThE supplied with fuel gases. IThE in the scope of application of this document shall be able to be operated under the following ambient conditions:
- temperature range;
- during operation: +5°C to +40°C;
- during transportation and storage: -5°C to +55°C;
- relative humidity: up to 90% at 20°C, non-condensing.
This document covers the significant hazards, hazardous situations and events listed in Appendix A for oxy-fuel IThE, associated gas supply systems and protective systems on the basis that they are used as intended and under the conditions specified by the manufacturer.
This document applies to:
- gas distribution system, beginning in the direction of flow with the manually isolation main shut-off valve at the inlet of the thermoprocessing equipment;
- burner, burner assembly and ignition devices, open firing;
- Safety control system (protective system).
This document is applicable to all types of combustion of fuel gases with atmospheric air, compressed air or oxygen. This document also includes necessary requirements for user information. This document does not apply to manual burners, systems for flame spraying and micro soldering torches.
This document does not apply to systems for welding, cutting and associated processes using plasma and laser technology. This document does not cover the hazards arising as a result of the release of flammable substances from the products processed in the IThE.
This document is not applicable to electrical wiring and heavy-current wiring connected upstream of the IThE control cabinet/control panel/protective system.
Noise and optical radiation can cause significant hazards when using gas welding equipment. These are not covered in this document.
This document is not applicable to oxy-fuel IThE, associated gas supply systems and protective systems manufactured before the date of publication of this document in the Official Journal of the EU.

This document refers to manual blowpipes and stationary machine blowpipes with free burning flames for heat treatment of work pieces. These blowpipes are, due to their type of construction, designed for special applications and do not fall under the scope of EN ISO 5172:2006  and EN ISO 9012:2011.
This document does not apply to manual and machine cutting blowpipes according to EN ISO 5172:20061.
This document contains technical regulations, specifications and tests.
Blowpipes are intended for gaseous fuels in connection with oxygen, compressed air or aspirated air.
Flow rates are not expressly limited and depend on the thermal process to be performed.

This document specifies requirements and test methods for air-aspirated hand blowpipes.
This document applies to blowpipes for brazing, soldering, heating, fusion and other allied thermal
processes which use a fuel gas and aspirated air (injector-type blowpipes) and are intended for manual
use.
This document is applicable to:
— air-aspirated hand blowpipes which are fed with a fuel gas in the gaseous phase, at a controlled
pressure by a regulator, through a gas supply hose;
— air-aspirated hand blowpipes which are fed with a liquefied fuel gas in the gaseous phase at the
container pressure, through a gas supply hose;
— so-called liquid-phase blowpipes which are fed with a fuel gas in the liquid phase, and where thermal
evaporation takes place within the blowpipe.
It does not apply to blowpipes in which the fuel gas leaves the injector in the liquid phase, or to so-called
“cartridge” blowpipes where the gas supply is fixed directly onto the blowpipe and possibly constitutes
the shank.
NOTE Figures 1 to 4 are given for guidance only, to facilitate the explanation of the terms. They do not
specify the construction details, which are left to the discretion of the manufacturer.

This document establishes the general specifications, requirements and tests for devices located on the high-pressure side of acetylene manifold systems up to 2,5 MPa (25 bar) as defined in ISO 14114. It does not apply to high-pressure piping, high-pressure flexible hoses or pressure regulators.

ISO 10225:2013 specifies the gas letter code to be used for marking the equipment for gas welding, cutting and allied processes, when the full name of the gas cannot be used.

This document lays down the dimensions and specifies the characteristics of the constituent parts of hose connections for welding, cutting and allied processes, for example for pressure regulators according to EN ISO 2503 and blowpipes. The suitability of the hose connections mentioned below will be considered according to the applied pressure range. This document does not cover the design of the hose tail inserted into the hose. This is specified in EN 1256.

ISO 5175-2:2017 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.
ISO 5175-2:2017 does not specify the location of these devices in the gas system.
ISO 5175-2:2017 in not applicable to safety devices which incorporate a flame arrestor, covered by ISO 5175‑1.

ISO 5175-1:2017 specifies the general requirements and tests for safety devices for fuel gases and oxygen or compressed air incorporating a flame (flashback) arrestor used downstream of manifold, cylinder and/or pipeline outlet regulators, and upstream of blowpipes for welding, cutting and allied processes.
ISO 5175-1:2017 does not specify the location of these devices in the gas system.
ISO 5175-1:2017 is not applicable to safety devices not incorporating a flame arrestor, covered by ISO 5175‑2.
ISO 5175-1:2017 does not apply to the use of safety devices incorporating flame arrestors for applications with premixed oxy/fuel or air/fuel gas supply systems, e.g. downstream of gas mixers or a generator to produce hydrogen/oxygen mixture by electrolytic decomposition of water.

This document provides guidelines for periodic inspections of manual gas equipment for welding, cutting and allied processes placed downstream of the gas cylinder’s valve as shown in Figure 1 or, in the case of centralized distribution, downstream from the tapping point, since commissioning.
NOTE In some cases, gas cylinders can be replaced by cylinder bundles.
This document applies to gas welding equipment intended for professional use which utilizes compressed gases up to 300 bar (30 MPa): acetylene, liquefied petroleum gas (LPG), methylacetylene-propadiene mixtures (MPS) and carbon dioxide (CO2) and related mixtures.