eratic welds & low pressure

Date 04-01-2006 00:50

I have a new problem I could use some advise on. I have a few weld cells that, When my manifold supply reaches 500-600 psi, I begin to loose my pulse. My Manifold line pressure is set at 75 psi, and we are using a 85/15 mix (argon CO2). We had seen a minor change in some of the welding cells previously, but it was only minor. Now we are using new Fronius equipment and they seem to be very sensitive to the lower pressure in the Gas Banks that supply our system. We were assumming that the change was due to a higher concentation of CO2 toward the bottom of the Banks. We recently tryed a 92/8 mixture, thinking that a higher argon content would enable us to utilize more of the "leftover", but the results were minimal.
Any Thoughts?!

By aevald

Date 04-01-2006 06:16

Hello Mudbone, in your post you refer to losing your pulse, are you speaking of the welding process that you are using as being a pulsed process and this changes as the pressure becomes lower in the supply lines of your manifolded system? I might suspect that the mixer portion of your gas system isn't working properly. Do you have any way to take a sample of the shielding gas as you loose the "pulse" and analyze it to see what it's make-up is? Upon further studying of your post I may have misinterpreted your gas system, are these manifolded bottles of a pre-mixed 85/15 gas or are you mixing bottles of argon with CO2 to get the mix? Whichever way is in operation in your facility it sounds as if you need to have the shielding gas analyzed to find it's true make-up. See if you can Tee into the gas supply line and when the problem shows up take a sample of the gas from the line, get it checked for make-up and then proceed from there. Please post your results, I would like to hear what you found. Best of luck and Regards, aevald

By mudbone (*)

Date 04-20-2006 00:22

Yes, we are using pre-mixed gas. we only have the problem when the bottle pressure approaches 500. We have also noted that the problem is less severe as the outside temprature goes up. (the cylinder banks are stored outside). My gas supplier describes the problem as "stratification" (seperation of the gases). But even he is puzzled that this happens at 500 +/-. normally he would expect it below 200. but this may all be a mute point now. I've just received a "green light" to persue a bulk system and mixixg station. This should eliminate the issue. Thanks for your comments.

By ssbn727 (*****)

Date 04-01-2006 06:56

Hi Mudbone!

I personally could'nt answer your question without knowing more about the details regarding the design and makeup of your specific manifold gas delivery system and how it is integrated into your weld cells but, if you were to describe more details of the system to a gentleman who I consider an "Expert" in GMAW robotic welding cell design optimization. A proven "genius" in diagnosing & correcting problems to pointing out common mistakes made in the decision making process due to a lack of proper education regarding welding process control and management...

This link will enable you to pose your query directly to Ed so long as you are able to supply him with more specific details involving your shielding gas delivery system:

http://www.weldreality.com/discussion/

Ed should be able to steer you in the right direction...
Hope this helps.

P.S.Don't forget to at least check out the educational materials Ed has available for purchase.

Respectfully,
SSBN727
Run Silent... Run Deep!!!

By mudbone (*)

Date 07-30-2006 01:48

Installed The Gas Mixer System over the 4th of July Shut-down. So far, all of our gas problems have gone away!