Abstract: The present invention discloses an automatic self-adjusting thermally powered expansion valve for controlling the flow of refrigerant to an evaporator of a refrigeration system. The valve includes a differential fluid amplifier transducer which produces a constant flow of refrigerant independent of the liquid line pressure and includes a generally cylindrical interior with an inlet chamber having an inlet port and an outlet chamber having an outlet port and an orifice between the chambers providing a passage for the flow of refrigerant through the valve. The flow of refrigerant through the valve is regulated by a valve element, which moves longitudinally within the chambers with respect to the orifice. The longitudinal position of the valve element is controlled by force generators and sensors. The position of the valve element depends on the fluid pressure and the size of the pressure disks, and the spring constant of the compression spring.