What is the definition of minimum and maximum operating pressure differential?
Minimum operating pressure differential is that which is required to open the valve and keep it open. For 2-way valves, this is the pressure difference between the inlet and outlet ports. For 3-way and 4-way valves, this is the pressure difference between the pressure and exhaust ports. The maximum operating pressure differential refers to the maximum difference in pressure between the inlet and outlet against which the solenoid can safely operate the valve.