How do you size a control valve for liquid service?

Liquid valve sizing using ISA/IEC equations: Calculate required Cv = Q * sqrt(SG / delta P), where Q is flow (gpm), SG is specific gravity, delta P is pressure drop (psi). Apply correction factors: Fp for piping geometry (reducers), FL for liquid pressure recovery, and FF for critical flow factor. Check for flashing (downstream pressure < vapor pressure) and cavitation (minimum pressure in valve < vapor pressure). Size valve so Cv at normal operation is 60-80% of valve rated Cv. Select valve with adequate rangeability for minimum to maximum flow. Verify noise and velocity limits.