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 refrigeration system expansion valve (10) includes a body (12) having an inlet (20) and an outlet (22) and a valve assembly (24) within the body (12). The valve assembly (24) includes a first port (28) communicating with the inlet (20) and a second, larger port (30) communicating with the outlet (22) and further includes a pin (32) having a first pin portion (34) received by the first port (28) and a second pin portion (36) received by the second port (30). A stepper motor (100) attached to the valve body (12) cooperates with an actuator assembly (60) attached to the pin (32) to induce longitudinal movement into the pin and thereby control refrigerant flow through the valve.

Abstract: This inlet strainer (160) is for a thermostatic expansion valve (100) having an inlet fitting (114). The inlet fitting 114 includes an elongate passage (152), with an inlet opening at one end and a strainer-receiving opening at the other end, and a transverse passage (156) communicating with the elongate passage (152) between said ends. The strainer assembly (160) includes a closed outer end (162) threadedly connected to the fitting (114), a strainer tube (164) extending into the elongate passage (152) to a point beyond the transverse passage (156) and a closure ring (166) received in sliding relation within the passage (152) so that dirt is removed from the refrigerant before entering the valve port.

Abstract: A shuttle valve (10) for use in a dual refrigerator system (100) and operated by controlled refrigerant pressure lines (120, 122) to provide that either one or both of two evaporators (104, 106) are active. The valve (10) includes piston chambers (30) at each end having an outer portion (26) communicating with pressure lines (120, 122) and an enlarged inner portion (32) and an intermediate chamber (21) having valve seats (22) at each end. The valve (10) includes inlet and outlet ports (14, 16) communicating with the piston chamber enlarged portions (32) and an outlet part (18) communicating with the intermediate chamber (21). The valve (10) also includes a piston assembly (40) having opposed pistons (41, 42) interconnected by a biased push rod (44) and mounted in associated piston chambers for closing associated inlet ports (104, 106).

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 refrigeration system expansion valve assembly (10) includes a valve body (12) having an upper portion (14) an intermediate portion (15) providing a valve chamber (17) and a valve port (18), and a lower portion (16). A valve inlet (20) and outlet (22) communicate with the valve chamber (17) on each side of the valve port (18). A piston assembly (24) is mounted in the body (12) for closing the valve port (18). The piston assembly (24) is actuated by a push rod assembly (26) driven by a stepper motor 28. The push rod assembly (26) includes a threaded member (102) slidingly and non-rotatively mounted in the body (12) and linearly driven by the motor shaft (30) which is threadedly received by said threaded member (102). The piston assembly (24) is urged into engagement with the push rod assembly (26) by a return spring (36) and includes a fluted nose portion (80) and a bleed passage (90, 92) communicating valve chamber (17) and the spring compartment (75).

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.