Torch Flashback Arrestor is a device designed to quench flashback. When incorporated with a cut-off valve it will automatically shut off the gas flow. This must be installed on the outlets of both regulators, and/or torch inlets. This is used in oxy-fuel welding and cutting to stop a flame from re-entering a gas pipe or gas cylinder, either by cooling or extinguishing the flame. Torch Flashback Arrestoris a device fitted to the opening of an enclosure or to the connecting pipe works in a system of enclosure. This allows gases or vapours to flow under normal operating condition, but prevents the transmission of flame and stops flame in order to prevent a large fire or explosion.