What is the design basis that is used to determine the "Computed Mass Flow rate" in the relief valve synthesis for liquids?

The reason for the question is for a current application, API 520 part 1, 3.8.1.2 along with Crosby sizing program were applied. The results were lower than the Caesar results by 35 - 40%.

A couple of questions on the values to be used:
1. Supply Pressure: Is is intended that the supply pressure used be when the valve is fully open at required percent of overpressure? Which is the relieving pressure (psia)
2. Orifice diameter for relief valve application should be based on the manufacturer's maximum value? As with the gas relief valve synthesis.
3. Does Caesar calculate the inlet and outlet piping losses based on flow, or assign a percent to the inlet pressure?

Thanks,

All of the computations in that module came from the paper discussed in this (previous) thread.

I believe you're familiar with this post?

Thank you Richard,
I am confused. The paper is based on steam (compressible flow) how is it applicable to the liquid application?