Question about progression of travel while tig on pipe is in a fixed position.
Hi, I am teaching myself how to tig on pipe (both stainless and carbon steel) and want to know what the proper procedure is to make the weld when in the fixed position and the pipe cannot be rolled such as when being tested for a cert.
I was shown several years ago about rolling the pipe and working from about the 3 o'clock position and working uphill ( 2" stainless), but was wondering about larger diameters that cannot be rolled or just by nature of where it would be a fixed position weld.
Any advice would be appreciated. Thanks
except for pipeline welds, most pipe is welded uphill. rule of thumb is if you can roll it, then you roll it because you generally get a better weld.
But... when you weld uphill , you need to offset where you start and where you stop. like almost to the point where it starts to be downhill.
what i am saying is instead of starting at dead nuts 6 o'clock, start at about 730. and weld to 1030. Then start at 730 and weld all the way bach to 1030. next pass will start at 530 and so on.
that spreads out all the stops and also will distort less.
and then there is always that situation where there is a pipe on either side of the one you are welding and one underneath too.
Then you just do what you gotta do to get it done.
most pipe welding codes other than api pipeline codes call for welding uphill.
hope this helps,