Abstract: This oil level control device is for a refrigeration system, the control device being attached between the compressor and the oil supply. The control device includes a housing having an inlet communicating with the oil supply and an outlet communicating with a compressor sump; and a solenoid valve controlling flow from the oil supply into the compressor sump. A sensing chamber having a fixed probe providing a proximity detection system detects the oil level in the sump and responds to a change in the complex permittivity of the oil as the oil level rises and falls to generate a signal that controls the supply of oil to maintain the oil level in the compressor. Circuitry is provided having an input connected to the output of the sensor and an output connected to the solenoid valve.

Abstract: This combination expansion valve and check valve (18) includes a valve body (22) having an inlet (24) and a outlet (26). A control-valve (28) is disposed between the inlet and the outlet which controls flow through the valve when refrigerant flow is normal and pressure is higher at the inlet than the outlet. A by-pass conduit (60) is connected between the inlet and the outlet. A check valve (58) is disposed in the by-pass conduit within the valve to block flow through the conduit when the expansion valve is operating and to permit flow through the conduit when flow is reversed.

Abstract: This thermostatic expansion valve (12) is intended for use in a refrigeration system (10) which includes a compressor (14), a condenser (16) and an evaporator (18). The valve (12) includes a valve body (20) having an inlet (26) and an outlet (28). A valve port (34) and a valve element (38) are disposed between the inlet and outlet. Upper and lower diaphragm assemblies (24, 25) are provided at each end of the valve (12) connected to associated sensing bulbs (56, 58) at the inlet and outlet respectively of the evaporator (18). A push rod assembly (40) operatively interconnects the upper and lower diaphragm assemblies (24, 25) and modulates the valve element (38) in response to the change in differential temperature across the evaporator. A compression spring (36) acts directly on the valve element and provides an adjustable feature.

Abstract: This valve (12) for sensing and purging non-condensible gases in a refrigerant includes a valve body (30) having a lower refrigerant inlet (32), an upper exhaust outlet (36) and a valve passage (44) therebetween controlled by a valve element (54) extending between a spring (72) and a diaphragm (86). A housing (100) containing a "pure" refrigerant charge and a spring (110) are provided at the other side of the diaphragm (86) and the housing (100) is exposed to temperature of the system refrigerant. One side of the diaphragm (86) is subjected to the combined pressure of the spring (72) and the pressure of the system refrigerant at the inlet (32) and the other side of the diaphragm (86) is subjected to the balancing pressure provided by the combined pressure of the refrigerant charge and the spring (110). The valve (12) opens in response to increased pressure of the system refrigerant at the inlet (32) resulting from the presence of non-condensible gases and exhausts the gases to atmosphere.

Abstract: This combination expansion valve and check valve (18) includes a valve body (22) having an inlet (24) and a outlet (26). A control valve (28) is disposed between the inlet and the outlet which controls flow through the valve when refrigerant flow is normal and pressure is higher at the inlet than the outlet. A by-pass conduit (60) is connected between the inlet and the outlet and includes an external conduit (62) and a passage (70) within the valve communicating with the outlet. A check valve (58) is disposed within the passage which selectively blocks flow through the conduit. The check valve includes a floating disc (66) moving between spaced check valve ports (61, 63) to block flow through the conduit when the expansion valve is operating and to permit flow through the conduit when flow is reversed. Two identical valves (18a) and (18b) are reversely connected to tandem to operate alternatively as expansion valves in a heat pump system (10).

Abstract: This expansion valve includes a valve body providing an inlet chamber and an outlet chamber separated by a compound valve. The compound valve includes a check valve seat defining a valve port receiving a check valve element and the check valve element includes a control valve port receiving a control valve element. During normal refrigerant flow conditions when the pressure in the inlet chamber is greater than the pressure in the outlet chamber, the check valve remains seated while the control valve element meters refrigerant flow between the two chambers. During reverse refrigerant flow, when the pressure in the inlet chamber is less than the pressure in the outlet chamber, the check valve is urged away from the check valve seat to provide for relatively unrestricted refrigerant flow between the two chambers.