Sounds like gas valve is jammed on, mate. Especially if it does it even when the machine is turned off.
Follow the pipe into the machine to find the valve. Sometimes you can free them by whacking carefully with a spanner or small hammer. Dunno where to get a new one, somebody likely to be along soon who knows more about Einhall than I do.
Gas solenoid stuck open sounds sensible. Probably worth checking the gas doesn't flow out even when the machine is disconnected from the power socket - could be a crazy electrical thing going on.
Would definitely try disconnecting the machine from the wall before ordering a new valve. That would rule out wiring. If it were wiring chances are the connectors were disturbed when changing the gas pipe.
inside torch has 2 wires and on other ned where it screws into welder i one is poping out
i have looked in shop and cant seem to see any
anyone a link,or someone who can make one
thanks