#### JimGnitecki

##### Active Member

In my guided training, I am currently welding 3/16" thick 3" x 6" aluminum 5000 series coupons, and am surprised at how quickly the pressure gage on the Argon tank has fallen from 2000 psi to 900 psi. I'd like to be able to predict my usage at least roughly and plan for my cylinder refills.

My tank is an 80 cu ft size. And apprently, once the tank hits 500 psi, it's time to refill it since the psi is then too low to create a fully reliable consistent flow rate. So, I guess the actual usable capacity is (2000-500) / 2000 x 80 = 60 cubic feet.

Usage is measured as CFH, and my current welding requires about a 15 CFH delivery rate. So, the IMPLICATION is that my tank will last for 60 / 15 = 4 hours = 240 minutes of ACTUAL WELDING time.

**When running a 5/16" wide bead in 3/16" thick 5000 series aluminum coupons, what is the LIKELY speed in inches of weld bead per minute, when you are doing things correctly?**

IF everything I wrote above is correct, then once I have that inches/minute speed, I can figure out how many inches of bead I can run with my remaining Argon.

Jim G