I have an application on a 4500 ton chiller using R22 that involves installing a valve on the suction side on the compressor.

My question is, what is the added pressure due to installing a 24" butterfly valve instead of a 26" butterfly in this line. The temperature of the R22 is 37 Deg F and 66 PSI.

This is a 2 stage Carrier Centrifugal Compressor, is there any way to determine the added HP due to this additional pressure drop?