Control Valve Sizing

The ISA75 program carries out valve sizing according to the ANSI/ISA S75.01 - 1995 standard.

It only concerns itself with the valve sizing and potential choking regimes (Sonic flow for gases or flashing/cavitation for liquids).

Reynolds number calculations are performed for liquids but the graph published by ISA 75 has been replaced by a formula which fits the graph in the standard with reasonable accuracy.