Line dimensions is the nominal diameter with the solenoid valve ports to generally be fitted to the provision and actuator piping. Often, the connection type is additionally specified. Optimum Operating Pressure Differential (MOPD): Parker solenoid air control valves are meant to be shifted by the use of an electrical solenoid. https://pneumatic-actuator17037.smblogsites.com/15839111/butterfly-valve-an-overview