Expansion device with shutoff mechanism

摘要

An expansion device that is able to perform the functions of refrigerant expansion, flow control and shut-off. A cage (26, 27, 28, 30, 34, 36 and 38) extends from the ends (14 and 16) of a body (12) and supports a screen cover (32, 40) . An orifice tube (46) extends through the body (12) and a conical shaped valve seat (48) forms an outwardly flared inlet to the orifice tube (46) . A plunger (50) defines a conical shaped valve end (52) for engaging and sealing the conical valve seat (48) to prevent refrigerant from entering the orifice tube (46) . A rod (54) extends from the valve end (52) to react with a solenoid coil (56) for moving the valve end (52) into and out of engagement with the valve seat (48) . A spring (58) interacts between the plunger (50) and the solenoid (56) for urging the plunger (50) into the valve seat (48) .