Gas Pressure for Mib welding

[idahoborn399]

I have a Weld Pak 100 and have it set up for Mig welding. I can not find what the gas pressure should be. Please Help!

[EdKing]

You need to set the flow rate, not the pressure for MIG welding. It should be set around 30 to 40 cubic feet per hour.

Ed

[idahoborn399]

Thank you for the info. Do not know why this info so hard to find.

[Gadget]

I was always told to open the valve fully to seal the stem. Otherwise there could be some leakage around the valve stem. I guess I could have heard wrong though, anyone else have any idea if that is right or wrong?
Dan

[woofer456]

Gadget is right, on high pressure cylinders the valves are double seated meaning when fully open the steam seats at the top to prevent leakage
Bob

[arandall]

This forum is really proving to be useful! Today I learned about the double seal on the tank valves from Gadget and Woofer. With the poor quality valves on some of the bottles I have received lately, it's good to discover a way of insuring you don't waste any expensive gas. My last bottle did leak down, and I always close the valve, and relax the regulator diaphram when I'm done.

Cheers,

Art R.

[KHK]

I was always tought to open the valve all the way. If something happened on the high pressure side, I would NOT place any part of my body near it, just run for safty.

keith

[Gadget]

Guys,
Here are a couple of photos of a propane tank gas valve. The first one shows the valve down which would be seated closed. The second is full open with the seat closing the stem area.
Propane is not nearly as high pressure as argon but I assume for safety reasons it too has a stem seal.

Dan

[KHK]

I think propane could generae a couple of 100 psi. A full argon bottle is about 3,000 not a good compairsion. But the visual view is great, the Idea is the same.

keith

[kb3gun]

I run my flow between 20 and 30 (closer to 20) and have no problems. I concur that the bottle valve should be fully opened.