The Relief Valve Synthesis output requires that both the Thermodynamic Entropy and Subsonic Vent Exit limits be greater than 1.0. Otherwise, the thrust value is to be ignored.

We are evaluating existing installations where we are stuck with what exists. Generally, we have been able to meet the Thermodynamic Entropy condition, but are not able to meet the Subsonic Vent Exit limit.

My question is: What is the basis for the determination of the Subsonic Vent Exit Limit? or How does Caesar compute this, what is it a ratio of?

Regards,

The majority of the calculations found in the Relief Load Synthesis processor were developed in ASME Publication 75-WA/FE-23 "Steam Flow through Safety Valve Vent Pipes" by H. E. Brandmaier and M. E. Knebel.

You may see the paper in this post:
http://65.57.255.42/ubbthreads/ubbthreads.php?ubb=showflat&Number=20567&page=2

Hope this can help you to understand the theoretical basis.

Best regards.