Siemens 656-0009 3-WAY ASSEMBLY, 1/2", WATER, 2.5 CV OR AIR STATION PILOT VALVE 10-15PSISiemens 656 0009 3 Way Assembly, 1 2", Water, 2. 5 Cv or Air Station Pilot Valve 10 15psi This is a 656 Series Valve Assembly with a 1 2" Line Size, with 3 way Pilot Valve Action and Flow rate of 2. 5 Cv. This item can also serve as air station equipment which rapidly responds to large volume demands and supply pressure variations. This can be used in two pressure systems for either day night or heat cool applications. This pilot valve has a 1 2" OD