What should be the root gap for welding of A106 Gr B pipe for procedure qualification Filler wire:ER70S2 of 2.5 mm.Root welding should be by weave or string method.ON what basis electrode dia and Root gap and bevel angle is selected.
The root gap welded manually (vary due to welders abilities), it is best to always be able to slip the filler wire through the gap between the bevel land with little or no restriction of the filler wire, some welders try to close the gap tight but often this will cause concavity on the bottom half of the overhead portion of the weld where gravity works against you .
Thus 2.5 mm + you are allowed 1/16" above or below this number in the parameters of the WPS, for joint preparation. This should be reflected in an accurate drawing of the weld as proposed in the Weld Procedure Specification.
Bevel should be the standard 30 degree bevel the pipe will come with typically. The land on the bevel can be from 0 to 1/16" or per the standard bevel pipe you receive. All these should be noted on the WPS.
BTW the wire dimension can also change up or down if the WPS notes 3/32" dia. filler wire used in the WPQR, it can be have substitution of 1/16" or 1/8" dia wire per the code acceptable to weld with. There are more variables that can be used but the procedure has to be tweaked to do this all.
Root Gap for ER70S2 Filler Wire of 2.5 mm
Re: What should be the root gap if i am using ER70S2 filler wire of 2.5 mm
