To the extent I know API 520 do not address the issue of Relief valve thrust force due to liquid.The paper by Brandmaier et al " Steam Flow through safety valve vent pipes" on which the CAESAR II Relief Load Synthesizer is based upon also does not address the issue of liquid.

Besides computing based on Bernoulli's eqn, is there any reference to paper/books where the issue with liquids has been discussed? For example I would like to know the role of the different input parameters in the computation of thrust force under "liquid" in the CII Relief load sysnthesizer.

Looking forward to tips from forum members.Also if someone can post any paper/link, his/her kind help will be highly appreciated.

Regards