Branch on B16.9 Fitting?

[Shmulik]

ASME B31.3 basically considers a branch as it welded on a run-PIPE.
ASME B31.3 and ASME B16.9 consider a fitting as a seamless pipe.

My question is: when a branch is welded on a B16.9 Fitting (elbow / reducer / tee / cap) – has this fitting been considered as "Unlisted component" acc. to 304.7.2 ?

Does size of branch makes any different? When branch is made of a #2000 (or heavier) coupling acc. to 304.3.2 (b)?
Thank you very much in advance!

 

[bernoullies123]

Yes, it would then become an unlisted component. A fitting strength is derived from a multiple of tests (burst, destructive etc.). Once you make a modification to the fitting it then becomes fabricated component which is unlisted and would have to be verfied in accordance with B31.3 as an unlisted component.

Have a search of this site as there was a pretty in depth dicussion of this same point. Well worth a read.