An improved modulating expansion valve includes a housing having a high pressure side, a low pressure side and a piston reciprocally mounted in a portion positioned centrally therebetween. A manifold is sealingly mounted above the piston, and a high pressure control passageway extends from the valve inlets, through the manifold, to a chamber on top of the piston. A low pressure passageway extends from the chamber through the manifold to the valve outlet. A pair of electrically operated solenoids open and close the high and low pressure passageways to operate the valve. Substantially infinite control of the solenoids provide for modulating control of the valve in a semi-hermetically sealed expansion valve.