I was putting a longer power cable on my Hypertherm Powermax 600 plasma cutter yesterday and while I had the cover off I also decided to chase down an air leak that I suspected was there. I have an external filter/regulator on the machine and found a leak there but when I screwed the assembly back on and applied air (no electric power at this time) I could still hear the hissing of a leak. I found that the drain in the internal filter regulator was constantly leaking yet there was still water trapped in the bowl. Then I wondered if this is always supposed to be leaking air as a way keeping water out of the air flow to the torch. Or is it some kind of pressure relief type valve? There was a bit of rust like particles in the bowl so I have immersed it in an ultrasonic cleaner as I thought maybe a bit of crud has caused the drain valve stick in the open position. Anyway, not sure if I have a problem or not - the torch worked properly before I started on the power cable change but would like it all to be correct before I put it back together and put it back on its cart. Thanks for any help or comments.