Often the gauge does not read very accurately at the low end, so even if
it reads zero on the tank gauge, you might be able to run the torch for
quite some time, especially the small torch. I just noticed that at a
seminar I went to, the tank gauge was zero, but everything kept working,
so we did too. Unless you know the tank gauge, I suggest you just run
it out until it quits working.

Richard



Bob Edwards wrote:

Maybe a strange question, but how low can the pressure go in an O2
cylinder and still have the regulator operate properly? My 20 cubic
foot O2 bottle has lasted almost two years with pretty regular jewelry
torch use (Meco midget and Little Torch). The cylinder pressure is
now down to about 475 lbs on the gage -- how low before I should
consider it empty and get it refilled, as I don't want to run out in
mid-project?

Regards,

Bob