Hello again my friend,

I have a Pressure Safety Valve in my system and I think that my load case it will be something like that:

1 - W+T1+P1+D1+F1 (OPE) or (OCC) ?
2 - W+P1+F1 (SUS)
3 - L1-L2 (EXP)

I don't know if I have to consider PSV in operation or occassional case...Does somebody can help me how to build my load case?

I have just one temperature (T1), pressure (P1), displacement (D1) and reaction force (F1 due to PSV).

Thank you very much.

Best Regards,

Saulo Cunha

1 - W+T1+P1+D1+F1 (OPE with PSV)
2 - W+T1+P1+D1(OPE without PSV)
3 - W+P1 (SUS)
4 - L2 - L3 (EXP
5 - L1 - L2 (occ, effects of PSV only considering non-linear boundary conditions, not a stress compliance case)
6 - L5 + L3 (OCC, this is your occasional stress compliance case)

Thank you very much Richard....

Could you help me with just one more thing ?

I have a PSV Support (Attached) here and I made something like that:

I modeled a pipe ( with ambient temperature about 21 C) and I put a cnode (with anchor) in both of end ... See attached the support that I'm talking about.

Please, Am I modeling it correctly? Could you please say me how I model and represent their restraints ?

Thank you very very much for help.

Best Regards,

Saulo Cunha

Yes that is correct. The CNode/Anchor correctly models the welded connection on each end of the dummy leg.

However, you may have issues with that ambient setting of 21C. The reason is that the dummy won't expand to the same magnitude as the vertical "tee branch-valve" assembly. Is the dummy leg really going to be 21C?

If you don't get this right, you can have artificially high loads and moments in your CAESAR II analysis, that won't exist in the real system.

Great Richard...

But about model, what do you recommend? Do you think that I model it with ambiet temperature, average temperature, or what ? Could I model it like a rigid element? Which is it better ?

Thank you for help again.

Best Regards,

Saulo Cunha

A rigid element will still expand due to thermal growth. The best recommendation would be to use the actual temperature of the dummy. You may have to ask for a field measurement.

I'm just warning you that it is most likely not ambient, and you have a square loop with one side at a different temperature. This will induce loads on the elements you'll have to deal with.