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