Flange type involved in application of Code Case 2901

[CrisDom]

I'm referring to thread794-433284 and TGS4 reply:

QUOTE
The research backing up this Code Case was specific to WN flanges. When there is appropriate research on the other flange designs, we will likely update.
UNQUOTE

I'm realizing that a lot of people (me too!!) is facing problems in applying Code Case 2901 to STD flanges (mostly because just a few knows it and understands all the implications).
Won't it be a little bit confusing the fact that CC 2901 will be inlcuded in the new Edition of ASME Codes (Div.1 and Div.2) and it will refer only to WN flanges?
I mean, ASME B16.5 rating tables only depend on flange material and not on flange type, so why the effect of external loads on the rating should be referred to flange type?
Shouldn't it be advisable to have the same approach to evaluate the effect of external loads on the flange rating, regardless the flange type?

Thanks

Cristiana

 

[TGS4]

That sure would be nice. Nevertheless, there is no research that would allow that to occur. Until that happens, it would be irresponsible to bring in unsupported rules. No?

 

[CrisDom]

I'm not saying that unsupported rules should be brought in, for sure.
I'm just saying that events that are supposed to have an impact on a pressure limit (limit that is idependent of flange type) should be treated in such a manner that allows an unambiguous approach to their evaluation, regardless the flange type.
From a practical point of view, uncertainty will remain for all the flanges but WN flanges.
So the theory, let's say, is ok, but practically the introduction of CC 2901 in the new Edition of ASME Codes won't clear up the situation at 360°.
I absolutely don't mean to belittle this change in the Codes and the process that led to this, in fact, but the problem is that it wouldn't be decisive and people (vessel manufacturers, engineers, inspectors...) will continue to argue about what to do in case the same loads are applied to nozzles with different kind of flanges.

Just thoughts...

Thanks

Cristiana

 

[TGS4]

I agree with your general concern.

Show me the research, and I will get it incorporated into the Code, just like I did with the research that was the basis of CC2901. Or if that research doesn't exist, get together industry and fund said research. If the issue is truly problematic, then industry should have no problem finding the monies to fund this research.