GB815622A - Improvements in or relating to valves for fluid flow systems - Google Patents

Abstract

815,622. Valves. CARRIER ENGINEERING CO. Ltd. Sept. 6, 1956 [Dec. 9, 1955], No. 27390/56. Class 135. A reversing valve for fluid flow systems comprises a primary chamber 21 containing a primary valve member 45 selectively operable to connect a high-pressure inlet 23 to either of two spaced ports 27, 28, and a secondary chamber 31 having a low-pressure outlet 44, spaced ports 40, 41 with connections 64, 65 to the ports 27 and 28 respectively, and orifices 40<SP>1</SP>, 41<SP>1</SP> each adapted for connection to the high- and low-pressure sides of the system. The secondary chamber contains a secondary valve member 58 responsive to the high pressure in the secondary chamber and operative to provide a flow path for high-pressure fluid through the secondary chamber and one of the orifices 40<SP>1</SP>,41<SP>1</SP> to the high-pressure side of the system whilst also connecting the low-pressure outlet 44 to the other orifice which then leads to the low-pressure side of the system. The hollow cylindrical valve member 45 has a thickened central part 46 slidable in an 0-ring seal 55 and has spiders 47, 48 spaced apart somewhat less than cross-members 53 or other abutments on a stem 52<SP>1</SP> so as to provide limited lost motion. The stem 52<SP>1</SP> is connected to the armature 52 of a solenoid 70. The secondary valve member 58 is formed with opposed heads 60, 61 spring loaded towards seats 38, 39 respectively. As applied to a refrigeration system operating on a reverse cycle and having a compressor 11, a condenser 13, a refrigerant expansion device 16 and an evaporator 17, the compressor delivery passes to the condenser 13 in the position shown through the valve 45, the connection 64 and the orifice 40<SP>1</SP>, the high-pressure above the valve head 60 holding this on its seat and so permitting refrigerant to return to the compressor from the evaporator 17 via the line 118, the orifice 41<SP>1</SP>, the seat 39 and the outlet 44. On energization of the solenoid, the primary valve member 45 rises to its upper seat 61<SP>1</SP> and highpressure fluid passes via the connection 65 into the compartment 34 so holding the valve head 61 on its seat. The high-pressure fluid passes via the orifice 41<SP>1</SP> to the coil 17 which now acts as a condenser. Gaseous fluid from the coil 13 which now acts as an evaporator returns via the orifice 40<SP>1</SP>, the valve seat 38 and the outlet 44 to the suction side of the compressor.