im sure you know this, but im going to tell you anyways... 5 PSI on the acetylene, NO MORE than 15, matter of fact, just to be safe, dont ever go past 10 PSI, if you go over 15, you will blow yourself up... stick with 5 PSI... for the Oxygen, go to 10 PSI, ive gone to 15, but its not really nessecary... and make sure you bleed the lines correctly when you are finished, because if you dont, the Acetylene will go past 15 PSI, and you will go BOOM...