Hi Everyone.

As per para. 304.5.1(b) of ASME B31.3 2010,

"A flange may be designed in accordance with the BPVC, Section VIII, Div.1, Appendix 2. using allowable stresses and temperature limits of B31.3."

As per above statement, can we use allowable stress and temperature limits of B31.3 in flange allowable of flange leak module (of caesar) ?

Let's say as per caesar library database of flange leake module for,
Flange material:SA-182 F304L
Flange allowable @ 400 C: 67.5403 Mpa

Whereas as per B31.3 Appendix A,
Flange material:SA-182 F304L
Flange allowable @ 400 C: 91.6988 Mpa

So,
Can I use 91.69 Mpa (instead of 67.54.03 Mpa) as flange allowable in flange leak module ?

In my opinion, that paragraph of B31.3 refers to the design of flanges that "may" be designed as the paragraph says.

In fact I would interpret your question as using a B31.3 paragraph when checking flanges according to Div2 procedure to design flanges.
Well, if I were your Client I would not approve such approach, mainly because I would think I am enough flexible accepting a body flange stress design procedure- that it is proved as giving unrealistic results- as a leakage criteria (based on the fact that nobody saw leakage of a flange correctly designed under ASME VIII and proper tighten in field).

Dear Mariog,

This is regarding Detail FLANGE LEAKAGE analysis.

According to C-II detailed flange leakage analysis, by default the allowable are taken from SEC VIII - DIV 1. why?

In our current project, client asked to use flange allowable from ASME B 31.3, which are lower values than SEC VIII - DIV 1.

Technically, which one is correct method to follow.

Durga,

I can't give you a "yes" or "no" or "do as I say" to such questions.
Of course I have an opinion, I made some comments in the past.
But the truth is this is between You, the Owner/ Client, and the the Owner’s Inspector or the Inspector’s delegates.

Hi, I will go ahead with ASME Section VIII Division 1 Appendix 2. It is more useful. In case of detail analysis most preferable option is FEA analysis.

Regards,
R.K.