Hello,

Can you please guide me how to calculate the reaction force on a closed PSV with liquid inlet and outlet? API 520 has formulas for vapor and two phase flow PSVs but I don't see anything for liquid flow? would you advise please?

Thanks

Please see
http://forums.coade.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=44239
and look in the pdf file for FR.
And please note that API doesn't give any formula about vapor and two phase flow PSVs in a closed flare system.

Thank you Mariog,

Are closed PSV forces referred in any piping codes?

As I know, the answer is negative. You can find some guidance in Peng's book.
In addition, for a liquid PSV, it is likely that cannot be a free jet effect in flow dynamics during open-close cycle of PSV. Counting as in paper is just conservative.

Thank you very much