SEC VIII DIV 1 - Fig 2-4 Exception?

[FilTrekJay]

Hello,
I am having trouble finding an appropriate answer to a very specific situation:
I am trying to acquire a CRN for a type of pressure vessel that my company has been building for some time now and am having difficulties finding an example in the code book.
With a loose flange being welded onto the top of a shell, in Sec. VIII Div. 1 Fig. 2-4(3) it is shown that the max. distance above the shell that the flange can be is c + 1/4", but what if a solid plate is welded within that range and the shell is to follow below that with minimal spacing between the shell and plate?
I have found a somewhat similar situation in Fig. UW13.1 where a head is attached to a shell with a plug welded band and single side fillet, but not for a flange.
I know that my design is significantly stronger than the design in the code book, I just can't find a way to prove this to ABSA, short of a full FEA and even then if it's not in the code book they probably won't approve it anyways.
Any help would be appreciated.
Thank you.

 

[SnTMan]

Got a sketch?

 

[FilTrekJay]

I do.
Thanks for the quick reply.

 

[SnTMan]

FilTrekJay, if I interpret your sketch correctly:

I think it is a stretch to apply any of the Figs 2-4 to the construction. It looks more like a type of double-fillet lap joint per Fig UW-13.1(b), and should be governed dimensionally by it. You may be able present this reasoning to ABSA, and point out not every permissable detail is shown in the Code. However this body can be a tough sell, good luck.

Regards,

Mike