MIG Gas pressure

Actually you don't use pressure, you use flow and it should usually be about

20 CFH unless you're welding outside in a light breeze and then you need a bit more, maybe 25 CFH.

Best Regards, Keith Marshall snipped-for-privacy@progressivelogic.com

"I'm not grown up enough to be so old!"

I've used bottles with 3000 psi on down to 100 psi. That is when I try to change the bottle. I have used this pressure range with .023 .030 .035 and .045 wire. most often using 75/25 mix but once using 80/20 mix. For some reason I have never got CO2 bottle with pressure of 3000 psi it is mostly 1500psi maximum pressure. I have no idea what the reduced pressure is to the welder when using flow gage regulator as I only set by CFH. When using Victor flow meter I use 35 psi to supply the flow meter as instructed by victor but I am sure the pressure is much lower after passing through needle valve that controls flow rate. I have a blood pressure gage that is calibrated in milimeters of mercury that might read welder input pressure if you really need to know.

Flow meters are set to different low side pressures, usually 35-50PSI. Be sure the one you use is compatible with your mig welder and doesn't have too high a low side pressure.

Smith makes flowmeter with 75PSI supply from regulator I believe.

I am using the factory supplied regulator. Any suggestions for just a plain off the rack regulator?

SteveB

It should be equipped with a flow gauge calibrated in CFH. Set it to 20 CFH. Tanks are rated in CF, so a 122 CF tank should last 6.1 hours at a flow of

20 CFH. That's actual trigger down time, of course. When you aren't actually welding, there's no flow.

Gary