[Ed from Ohiol]

To all welders, and Jody.


Just a quick question. Using a plasma cutter for portable use, what kind of compressed gasses can be used out of a tank in place of a compressor? O2, CO2, Argon Nitrogen? …
Which ones would you definitly not use? And why? How long do you think an 80 or 125cf tank would last,say at 100psi Thank you. Ed Oh.

[taylorkh]

Sorry about the late reply. I was browsing my Radnor catalog (a great reference if you can get one from Airgas/National Welders). The description of my Hypertherm PowerMax 30 indicates among other data

Gas Supply: Clead, Dry Oil Free Air or Nitrogen

so I guess that answers the what kind of gases question. The Flow Rate/Pressure tells me 3.5 cfm @ 65 psi. As flow rates are generally expressed in Standard cubic feet per time and tank capacity is also listed in terms of Standard cubic feet (measured at normal atmospheric pressure) my back of the envelope calculation would show that a 300 scf cylinder would supply my plasma cutter for about 85 minutes.

That said... the local Community College has a LARGE yellow (ESAB) plasma cutter which has two cylinders to supply gas. If I recall correctly one was nitrogen and the other was an Argon/Hydrogen. It could cut really thick metal. According to Miller, pure Nitrogen is good for cutting stainless steel.

Ken

[nickm]

Thanks for the reply Ken, I had a similar question which you've now answered.