Question

the device used to control the pressure on an oxy fuel cutting torch set is called

Answer 1

Note Acetylene is supplied in cylinders under a pressure of about 15 bar but welding is carried out with torch gas pressures typically up to 2 bar. Flame traps (also called flashback arresters) must be fitted into both oxygen and acetylene gas lines to prevent aflashback flame from reaching the regulators.

Answer 2

the CO2 gas is used.