I'm wondering what most folks do when analyzing lines associated with relief valves. We avoid dynamic analysis and run static equivalents, based on use of a dynamic load factor. Do you apply this reaction load to each change of direction, only certain ones? Also, do you run separate load cases, one for each change in direction or do you assume the reaction load on the elbows is simultaneous?

Nevermind - Loren Brown covered this well in a prior post. Itried to delete this but the system wouldn't let me. Thanks anyway.

http://65.57.255.42/ubbthreads/ubbthread...=true#Post11775

Goodsalt,
I read many time regarding previous post by Loren Brown as what you suggested but I cannot relate it to the situation I analyze.
Supposed I have 4 PRV's connected to flare lines with same operating temperature and pressure T1 & P1 respectively.
These are the following forces to be applied at a different bend:
1st PRV------1000N +Fy
2nd PRV------1000N +Fy
3rd PRV------2000N +Fy
4th PRV------3000N +Fy

In Forces/Moments tab in Caesar-II input file, does the Vector 1,2,3 up to 9 represent forces at different operating condition? If not, then
is F1 represent for force @ 1st PRV?
is F2 represent for force @ 2nd PRV?
and so on for 3rd and 4th PRV's?
Since I have 4 different forces in 4 PRV's opened individually or together, how could I input in the vector so that I can build a load cases as the following?

L1 = W+P1+T1----------------(OPE) INDIVIDUAL
L2 = W+P1+T1+F1-------------(OPE) INDIVIDUAL
L3 = W+P1+T1+F2-------------(OPE) INDIVIDUAL
L4 = W+P1+T1+F3-------------(OPE) INDIVIDUAL
L5 = W+P1+T1+F4-------------(OPE) INDIVIDUAL
L6 = W+P1+T1+F1+F2+F3+F4----(OPE) TOGETHER

Please correct me if I'm wrong with conclusion..!


Nald

Nald - I agree with what you have done - Vector 1 is F1 (input as FY = 1000N), Vector 2 is F2, and so forth.