Hello guys,
I first posted a similar topic back at the beginning of '07 and I need assistance again please.
Gerald gave me an excellent response but I need to take it further.
http://www.aws.org/cgi-bin/mwf/topic_show.pl?pid=58162;hl=As explained in my earlier post I am still confused with the difference between lack of root fusion and lack of root penetration.
For branch connections I have always believed that you must have complete root fusion/penetration??? (both edges of root fused) but now I am not so sure.
B31.3 Fig 328.4.4 shows that the hole for a branch connection can be up to 1/8" smaller (each side)than the internal bore of the branch connection.
If you take Fig 341.3.2 (c) and substitute a single bevel weld for the single vee weld shown and turn it 90 degrees you would have a similar joint configuration to the branch connection. You would then presumably have misalignment of the bore.
If you failed to fuse the bottom edge of the run pipe would that then be classed as "Incomplete penetration due to internal misalignment." If so you are allowed 1.5 " of incomplete penetration as per 341.3.2.
Similarly you could have no internal misalignment but still fail to fuse both edges and then it would be classed as "Incomplete penetration of Weld Groove.". Again, 1.5 " acceptable.
As you are all probably well aware it is quite easy to miss one edge of the root (without misalignment) if the welder has poor technique but I cannot find a picture of this in either B31.3 or AWS 3.0.
Both documents show Lack of Sidewall Fusion and Lack of fusion between adjacent passes (interrun) but not Lack of fusion at the root.
Any assistance would be greatly appreciated.
Regards,
Shane