Socket weld gaps

[liboil]

thread174-10800
Further to gaps in socket welds.On occasion these joints are radiographed to check that there is a gap however there does not appear to be any specification giving min and max gap.Asme/Ansi only refers to the technique to be used setting up the joint ie withdrawing the pipe by 1/16 in(1.6mm).The general view seems to be that it is important that there is a visible gap but that the depth of insertion is less important.Would it not be prudent for there to be a specified min and max.
A previous posting referred to what I understand to be the fairly common practise of pulling the inserted(bottomed out) pipe to one side,tacking and then pulling the pipe to straighten and set the gap.Is there not a danger that the tack may crack and that this may propogate during welding or service.Surely it is both bad practise and not as per Asme specified method.

 

[SNORGY]

Socket welds are not the only place where tack-welds are made and the pipe is subsequently bent and tweaked during fit-up. It happens with butt welds too. While I would imagine that it might not be ideal, the rationale might be that the tack welds are either "burned over" when the actual weld is done, or - better still - ground out before progressing over the previously tacked area with the closing welds.

Regards,

SNORGY.