# Liquid phase gas flow through valve

I have been trying to figure out how to calculate the required dimensions for liquid phase gas through a solenoid valve. Many companies (Swagelok, Bürkert, Asco) provide "Flow coefficient calculators" where you can enter values for the inlet pressure, outlet pressure and pick the medium flowing through the valve. There is no option to choose whether the gas flowing through the valve is in liquid phase or not though.

How would one go about finding the required size of a valve, if you know the pressure drop, required mass flow / volume flow and the medium flowing through it? Would you assume the flow to be just any incompressible fluid (i.e. water) and use

$$Flow \ coefficient = Volume \ flow \ \times \sqrt \frac{specific \ gravity}{dP}$$

Also, when would you have to be concerned about cavitation?