taken from burnsstainless.com

"When it comes to final welding, the first choice is to use the TIG process, although MIG (wire feed) can be used. Because the 30% lower thermal conductivity and 50% greater coefficient of expansion of stainless, it distorts more in the area of the weld than mild and alloy steels. When welding a stainless header tube to a stainless 3/8" thick header flange, it is a good idea to use as low a heat setting as possible (TIG welds should be a shiny gold color verses dark grey and dull, which indicates too much heat) and cool it immediately by quenching it with air or water to minimize distortion. Preheat will accentuate distortion and should be avoided as much as possible. Sturdy, non-flexible welding fixtures also greatly minimize distortion if the part is allowed to cool before removal from the fixture."

is this a sugestion for just welding the tubing to the head flange?

i know ive read in several places that it is not reccamended to cool welds. however, we all know that burns knows whats up

btw thanks for all the help casey, and that tight radius bend saved me!

 

Also curious

 

I think the easiest way i can phrase this is....... If your going to be doing quite a lot of welding on a large piece of SS you need to either let the weld quench to open air, and wait or quench it with water and continue to weld. As the statement taken from our site says, 'pre heat will accentuate distortion' well there it is, everytime you weld on something you are going to be pre heating the rest of the material eventually the piece is going to be so hot it will pull and twist like craazy.

As far as welding the tubes to the head flanges I do not believe we use this method however I'm not there everytime something is welded. You can usually tweak the tubes back into place after they pull with some simple massaging

You do not want to water quench with mild steel, or chromoly