Equivalent Pressure model for flanges

I understand that Caesar can check for equivalent pressure model through Caesar flange. I like to know what is correct procedure to do for activating this equivalent pressure model.

It is done automatically when you analyze the model. Just be sure to fill out both the pressure and the axial force and bending moment (SRSS the two bending moments and input that value).

On the same subject, here is a concern I expresed to Tech support and feed back from Loren.

Concern:
"Ceasar flange calculation option reviews in detail many stress scenarios. Some times all stress check will show satisfaction except the equivalent pressure check. I find that especially true in small flange when upset pressure is getting closer to the maximum flange ratting like for PSV. In this case there in not much pressure left to allow for bending moment.
How conservative is the equivalent pressure check? Is it really industry practice to keep this number high that 1 even in upset case?"

Loren reply:

"It is true that the equivalent pressure method is conservative. In fact, many B16.5 flanges will show a failure when employing this method, although they are protected from this requirement through a "grandfather" clause. There are other methods available for flange stress, such as ASME NC-3658.3, which is implemented in Caesar II 5.10 in the in-line flange analysis. This method is not implemented in the flange module though."

Would anyboby have more details to add?

Nick,

If you use the search engine on Flanges there is a wealth of information on this subject.

Regards