Some basic torch advice

[nybirdman]

40 years of pipe work we always set them7/30 psi.

 

[etpm]

It's hard to judge the contents of an acetylene cylinder from pressure alone. This is because the pressure varies greatly with temperature, much more so than oxygen. If you look online it is easy to find charts that will tell you how much gas is left in the cylinder because these charts show both temp and pressure. I am concerned about your pressure gauge that bottoms out at 100. I know that's the high pressure side but if it's off that much how accurate is the low pressure side? Acetylene gas is a little tricky. Above 15 PSI in the right container it can just plain blow up. The tiny space in the top of the cylinder isn't the right amount of space for the gas to explode. But a length of hose at a pressure higher than 15 PSI can be. If I was you I would get a good reg. They are cheap.
Eric

 

[Mtr79821]

First post but here's victor for acetylene

 

[Mtr79821]

and propane