A solenoid valve useable as a pilot for actuating a flow control valve of the pressure responsive type, the solenoid valve having a coacting valve ball and seat and means upstream of and reciprocable axially of the valve seat for actuating the valve ball which includes a portion for holding said valve ball engaged with the valve seat, a portion spaced from the seated ball for unseating said ball and a valve cage portion in spaced surrounding relation to said valve ball. The valve ball actuating means has at least a portion of magnetic material adapted to function as an armature for a solenoid so as to be attracted thereby for unseating the valve ball, the solenoid including an electromagnetic coil having multifilar windings of fine gauge wire of the order of 0.004 of an inch whereby the coil is of reduced volume and increased efficiency and said solenoid is relatively minute.

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