ROOT GAP for square weld

[RE52]

Hi every body,
please tell me according to any standard how much gap should be considered for welding the 1 inch stainless steel pipe by TIG process in square weld _____ll_____ . this pipe is for drainage line.(can we weld without any gap? penetration is essential?)

 

[weldtek]

There are so many variables, it's difficult to provide an answer. The best thing to do, is ask the welder, assuming he's qualified and competent. I will say that it is possible to achieve full penetration on 1" sch 40 using a sq groove with little or no gap, but, again, consult with the welder for your specific application.

 

[metengr]

The root gap should be 1/16".

 

[gtaw]

I have clients that weld square groove butt joints up to 1/8 without any root opening. They qualify their welders on nickel alloy, austenitic stainless, and carbon steel pipe using GTAW and a root purge of argon. The results have been very good.

Al

 

[stanweld]

For small diameter pipe/tube welds with wall thickness < .150", you should consider automatic autogenous (no filler metal) welding systems; square bevel, no gap. A zero gap may also be used for autogenous manual GTAW welds.
When weld filler metal is required by spec. or due to thickness, open the root to 1/16", especially when two or more weld passes are required.