Refrigeration system flow control expansion valve

摘要

A refrigeration system including a flow control expansion valve. A valve body defines a valve inlet for accepting refrigerant and a valve outlet for delivering refrigerant that has passed through the valve body. A metering head defines first and second passageways for fluid passing through the valve body. A cylindrical sleeve is mounted for controlled movement within the valve body and including a center passageway which in combination with the first and second passageways conveys fluid through the valve body to the valve outlet. A spring urges the sleeve in a direction relative the metering head to maintain both the first and second passageways in fluid communication with the center passageway of the sleeve. A valve actuator mounted to the valve body moves the sleeve against the biasing action of the spring to restrict flow through one passageway of the first and second passageways while allowing fluid to flow through another of the first and second passageways and said center passageway of said sleeve to the outlet. The valve actuator includes a control input responsive to an external control signal to initiate movement of the sleeve to a position for restricting flow through said one passageway.