Diaphragm solenoid valves are available for 3/8-3/4” pipes, have orifices from 9/16-3/4” are constructed of brass or stainless steel and have stainless steel seats. When energized, the plunger is pulled to the top plug, thus opening the small “pilot port” in the center of the diaphragm plate. This releases the pressure on top of the diaphragm allowing incoming pressure to lift it off the large center port. When de-energized, the solenoid plunger is pushed from the top plug by the kick-off spring and closes the pilot port. Fluid passes through the diaphragm bleed hole until pressure is equalized on both sides of the diaphragm to shut off the large port.