Not logged inAmerican Welding Society Forum
Forum AWS Website Help Search Login
Up Topic Welding Industry / Technical Discussions / Teflon house for argon lines
- - By caalfi3 Date 06-13-2008 20:02
I'm been using a Teflon hose for the argon lines of the Welding machine and the torch for the TIG process in order to control de purity (moisture), so far whit a great success. The problem is the Teflon hose is t rigid, it's a problem for the welder, we are looking for something more flexible (easy to handle).
Does anybody know if there is a better material that we can used for this aplication.
Thank you,
Parent - By Stephan (***) Date 06-13-2008 20:53
caalfi3,

please have a look upon:

http://www.aws.org/cgi-bin/mwf/topic_show.pl?pid=98335#pid98335

Great post that time initieated by aerowelder.

As you may follow the thread above, you will see that there was a particular subitem discussion on gas hose materials as well.

Hope this helps a bit...

Best regards,
Stephan
Parent - - By Steve.E (**) Date 06-14-2008 03:42
Hi caal , after many years of welding all sorts of materials including exotics such as Titanium Zirconium and Tantalum , I have never had reason to use anything but standard hose lines. For convenience on back and trailing purge lines we generally use clear vinyl tubing. If moisture content of your gas is a problem I would suggest another suppler.
Parent - - By swsweld (****) Date 06-14-2008 22:29
My first experience with clear vinyl tubing was a bad one so not a big fan. I'm not saying that the clear hose in not better for moisture purposes but it is not rigid enough for field work in my opinion.

My first job with a company that specializes in machine welding used it and I had the opportunity to make the first weld on the boiler outage on the 24"diameter 9% chrome 1" wall thickness. Pulling a K-ring. Things were going great....nearly tied in and one of the lesser experienced machine welders trying to see the puddle got too close and stepped on the clear hose. If it had of been the standard argon hose, no problem. Pulling a K-ring with no argon is not recommended. I hit the BRB immediately and luckily didn't blow through. Not the first impression I was trying to make.

Plus the 9% chrome was preheated to 350F I think so the heat could melt the clear hose if too close.
I agree with Steve.E that rarely is it necessary to use anything other than the standard hose.

To me the downside is not worth it.
If a company had the time and money to do a little pre job R & D or during the PQR's they could determine if moisture in the argon is a problem. If it's not broke...

BTW Thanks for the link to that thread Stephan.
Parent - - By DaveBoyer (*****) Date 06-15-2008 05:05
What material are Your "standard" hoses? Much of what I have seen is green rubber grade "R" oxygen hose with CGA-032 [5/8-18 RH] fittings.
Parent - By swsweld (****) Date 06-16-2008 01:41
Hello Dave, that's the same hose that I'm calling standard hose. That is what I've used almost exclusively in my career. The only exceptions were the one I mentioned above and if I remember correctly we used a higher PSI rated hose for the Narrow Groove GTAW process.

http://www.csnwelders.com/Anchor-100-1-4X1-GRN-xx-ARGON-ANR1069.html#ManuDetails
Parent - - By Stephan (***) Date 06-15-2008 13:59
Cheers Tim!

To be honest I am still having my problems in believing that the gas suppliers are the ones who may always be blamed with this.

As the moisture topic appeared now for several times I guess it might be quite interesting to know what the tricky physical details are, behind this issue.

As I am up to my ears with work presently I hope that I will find the time someday to come back on the very interesting coherences between gas hose materials and moisture contents in shielding gases.

Best regards,
Stephan
Parent - - By DaveBoyer (*****) Date 06-16-2008 04:33
Stephan, I have some Linde /L-Tec gear that has thermoplastic hoses. In theory at least, a hygroscopic gas could draw moisture through some hose materials by means of osmotic pressure. I don't know if this ammount could ever be large enough to be measurable, or cause problems. I have read cautions to never use hose for shielding gas that has been used in other gas service due to absorbed gasses from the prior use outgassing and contaminating the shielding gas.
Parent - - By Stephan (***) Date 06-17-2008 20:54
Dave,

I apologize for the late response!

You know, I am having the honor again to be guest of your great nation (as my friend Al said once, meanwhile it appears quite so that I am more often present in the United States of America than in Europe). :-)

I am in Florida currently to attend a conference, starting tomorrow.

Huuh, quite warm here but very - no... actually extraordinary - beautiful!!

Seriously Dave.

It has exactly to do with what you have described!

You know, whether or not it may cause considerable problems, hmm... I humble guess this is a question to be replied specifically to the welding application.

But as the issue "moisture in shielding gases" has been treated now for several times within the forums I guess, perhaps there might be real issues from time to time on site.

This again would however practically approve what the investigations have proved theoretically as practically (laboratory).

Hopefully I will find the time anytime to state somewhat on this.

Thank you again Dave, for your very interesting contribution!

Best regards,
Stephan
Parent - - By spgtti (**) Date 06-27-2008 00:58
In high purity, autogenous, automatic tube welding we always used capped and purged 1/4" SS coiled tubing for ID purges on critical welds to prevent any moisture from contaminating it. Everytime we used poly, teflon or argon gas hose we ended up with excessive color and hazing. We would hook our power supplies up with the same rigid tubing but AMI uses some kind of flex running to the weld head.
Parent - By Stephan (***) Date 06-27-2008 06:57
spgtti,

excellent contribution!

Thanks for that.

It shows me, at least rudimentarily, that there is a residual risk appearing to exist in specific areas, which are quite different from laboratory conditions!

Thus - so my humble interpretation - the study executed was worth to be executed.

By the way, using stainless steel hoses appears to be - as far as reported several times - anyhow the non-plus-ultra solution (no diffusion or effusion).

Being quite busy presently but having not forgotten to come back on this anytime.

Regards,
Stephan
Up Topic Welding Industry / Technical Discussions / Teflon house for argon lines

Powered by mwForum 2.29.2 © 1999-2013 Markus Wichitill