Oxygen welding, oxygen cutting device, gas welding machine, welding machine, gas welders, gas fire-breathing mouth for use in welding, welding torch, cutting torch, gas torch, gas torch handle, gas nozzle, gas cutting nozzle, gas welding and cutting device, pressure regulator, flashback arrestor, cutting blow pipes (gas-operated), pressure reducers (parts of machines), pressure regulators (parts of machines), welding apparatus (gas-operated), regulators (parts of machines), soldering apparatus (gas-operated), soldering blowpipes (gas-operated)