Gas (cfh) flow issues with these new miller machines.

By Kix

Date 03-07-2007 17:03 Edited 03-08-2007 14:23

Ok here's my delema... Running a new Dynasty 700 for GTAW and an Invision 456 with a new 75 series feeder. Problem is the guys are pegging the flow meters at 60cfh and above to get a decent amount of flow out of the torches. Torches in use are the new Weldcraft supercool 18's for GTAW and Bernard QT3-30 with a NS-1200B nozzel for GMAW (stock torches). The nozzel has some defuseing holes around the inside of the cup witch could be some of the prob, but i don't think it is. We are welding aluminum with this particular gun with a teflon liner in it. Could this be part of the gas restricting issue with the mig?

By SWP

Date 03-08-2007 14:15

You indicate that gas flow is restricted but at the same time state that the guys are running 60 cfh.
If the flow meter reads 60 cfh, you are flowing 60 cfh, whether there is a restriction or not.

I assume you must be having a shielding problem, not a restriction problem.

Maybe there is an issue with turbulence created by this torch setup?

I would check the gas supply system for leaks. If the gas system is extensive, check for oxygen contamination near the welder, and if O2 is found, work backwards to find and correct leaks. Or, hook up a bottle at the welder and see if it works better than the house gas system. At any rate, ensure the system has no leaks.

By Kix

Date 03-08-2007 14:30

Your right i should have stated my case a bit clearer. Problem is i'm not getting enough flow out of the end of the torch or the gun. Basically i couldn't cause turbulence if i wanted too. You know and i know you don't need to be running 60cfh out of a factory torch to get the bare minimum of coverage. #9 cup or the tig rig if your wondering.. I have flow checkers coming that we can put on the end of the torch and see what we got so i will post an update when i start to narrow things down.

By DaveBoyer (*****)

Date 03-09-2007 05:35

If any teflon tape was used anywhere on the system [I don't think it should have been] there may be shreds of it cloging some part of the supply line or torch. I am asuming You have the pressure guage type, not an actual flowmeter with a ball. Just My $.02

By DaveBoyer (*****)

Date 03-09-2007 05:48

For a barnyard measure of gas flow You need a 5 gallon bucket full of water, a 1 gallon milk jug, and a hose that will fit on the torch / gun nozzel. Immerse the jug in the bucket so it is full, turn it upside down and lift it partially out of the water but keep the open end submerged. Put the hose in the open end of the milk jug and time how long it takes to fill the jug with shielding gas. There are 7.5 gallons in a cubic foot, do the math.

By Kix

Date 03-09-2007 18:15

I think i'll wait on the flow checkers for the end of the torches. Can't say that i have any milk jugs lying around the shop, but i do have lots of 5 gallon buckets.