Here's what I have going on.   http://i11.photobucket.com/albums/a189/vdubin474/Nozzleweld.jpg  This vessel is not a stamped vessel, but was built in accordance to ASME Sec VIII Div 1.  In this picture you will see a full penetration nozzle weld.  The nozzle has a single bevel and a joint configuration similar to ASME Sec VIII fig UW-16.1 sketch (a).  As you can see in the picture, it was marked up for underfill.  The top stringer is very concaved and goes below flush of the O.D. wall of the nozzle about 1/16". 
      Our customer is rejecting this weld and our sub says it was inspected, signed off and should be acceptable.  Now I'm trying to find where in Sec VIII I can reference to see if this is in fact still an acceptable weld.  The only thing I can think of is, the underfilled groove weld portion of this weld met spec by still meeting the nominal thickness of the base material because of the root pen sticking through the backside, and the throat of the fillet weld portion was met.  I still can't find where it clearly states this and it may not.  I may be way off track here.  Any help on this would be greatly appreciated.

Thanks,
Kix