摘要 |
A constant flow rate expansion valve includes a refrigerant passage 5 having a fixed cross-sectional area smaller than that of a refrigerant inlet 1, a differential pressure control valve for controlling the differential pressure (P1 - P2) between an inlet pressure P1 and an intermediate pressure P2 generated by refrigerant flowing through the refrigerant passage 5 to be constant, and a solenoid for setting the differential pressure by an electric current. A piston 8 and a valve element 9 integrally formed with each other sense the differential pressure (P1 - P2), vary the opening degree of the valve element 9 such that the differential pressure is held constant. The piston 8 is fluidly isolated from the refrigerant inlet 1 by a diaphragm 6, preventing internal leakage along a sliding portion of the piston 8. <IMAGE> |