The microvalve device includes a pilot microvalve and a pilot operated spool valve. The pilot microvalve includes a pilot input orifice; a pilot output orifice, at least one of the pilot input orifice and the pilot output orifice having a cross-section flow area that changes as the pilot microvalve is actuated; and a passageway providing fluid communication between the pilot input orifice and the pilot output orifice. The pilot operated spool valve includes a spool having a surface in fluid communication with the passageway; a spool input port; and a spool output port, at least one of the spool input port and the spool output port having a cross-section flow area that changes as the spool is actuated. The spool valve is operable by the pilot microvalve such that a ratio of the cross-sectional flow area of the spool input port to the spool output port will substantially equal to a ratio of the cross-sectional flow area of the pilot input orifice to the pilot output orifice. The spool valve may be a microvalve or a standard size valve.