pressure regulator
Device placed at the outlet port of each cylinder; it lowers and stabilizes the gas pressure reaching the torch.
check valve 
Part for preventing gas from returning to the cylinder after passing through the pressure regulator.
adjusting screw 
Screw for controlling the gas pressure at the regulator outlet port, which corresponds to the gas pressure at the inlet of the torch.
working pressure gauge 
Dial-operated device whose needle shows the gas pressure at the outlet port of the pressure regulator.
cylinder pressure gauge 
Dial-operated device whose needle shows the gas pressure in the cylinder.