Abstract: A pressure reducing assembly is provided for managing refrigerant flow in a reversible HVAC system. Refrigerant lines from the system heat exchangers connect to bi-directional ports of a pressure reducing assembly which converts the high pressure refrigerant flowing from one heat exchanger into pressure reduced refrigerant that flows to the other heat exchanger. The pressure reducing assembly converts bi-directional refrigerant flow from the heat exchangers into unidirectional refrigerant flow through a pressure reducing device. Refrigerant emitted from the pressure reducing device flows out of the pressure reducing assembly to the other heat exchanger. The invention simplifies the interconnection of reversible HVAC systems by eliminating the complex plumbing and extra valves associated with conventional systems.

Abstract: A two-way flow solenoid-controlled expansion valve and receiver assembly for a two-way flow heat transfer system employing a refrigerant comprises a receiver and a valve body mounted on the receiver having two inlet/outlet passages. Either one of the inlet/outlet passages may be connected to a heat exchanger that switches from a condensing mode to an evaporative mode on refrigerant flow reversal while the other of these passages is then connected to another heat exchanger that operates in opposite manner. The inlet/outlet passages are each adapted to receive refrigerant from a condensing heat exchanger and deliver same through a separate check valve to the receiver and a flow control valve arrangement including two flow control valves independently operated by a proportional solenoid is operable to route and regulate refrigerant flow from the receiver to the other inlet/outlet passage that is connected to the heat exchanger that is then in an evaporative mode.

Abstract: In a vehicle with a liquid cooled engine and a heat exchanger such as an interior heater for the passenger compartment, an isolation device positioned therebetween for normally permitting flow of liquid from the engine cooling system to the heat exchanger and then back to the engine cooling system but for blocking flow to the heat exchanger when the liquid temperature is excessive. The device including a thermally responsive power means responsive to a high liquid temperature to block liquid flow to the heat exchanger and redirect the flow in bypass relation to the heat exchanger.