Originally Posted by 2door
I'm not following this idea of "purging" the pressure from the machine after finished welding. There should be no reason to do that. The tank valve should always be shut off after using it but that is to prevent loss of gas in the event there is a leak downstream of the regulator. Any compressed gas cylinder, especially a flammable gas, should be valved off after use.
The flow meter/gauge will not be damaged by pressure left on it.
Concerning my old and failed regulator/ meter, the tank valve was turned off before storing and no, it does not leak. The welder sat for a few months. I went to use it and the weld bead was horrible. I asked the old grey hair next door for help and advice. He has welded for a living for the last 50 or so years. That's all he does is weld things. Aircraft, medical, NASA, Government, and whoever else needs welding done.
A very good guy I might add too. Anyways I digress.... He fiddled with it and tried to do a few beads on some scrap. Then he asked me about purging the pressure off the regulator before storing the welder. I said it was not done. He laughed, told me what went wrong and why, and got me a new regulator from one of his suppliers at an awesome price.
The rest has already been told here.
Oh by the way I never zero the meter with the knob before storing and it has never done anything bad to it either, as instructed by the good welder guy next door.