GB1308093A - Pilot operated flow control valve - Google Patents

Abstract

1308093 Valves MURRAY CORP 14 May 1971 14961/71 Heading F2V A valve device suitable for an automotive refrigeration system, comprises a housing 1 having coaxial inlet and outlet connections 20, 5, respectively, and a valve sub-assembly B detachably secured to the inlet connection. This sub-assembly comprises a piston valve 35 mounted in a cylinder 29 and controlling communication with a chamber 30 on the downstream side of the piston valve through cooperating ports 31, 38 responsive to the pressures on opposite ends of the piston. There is direct communication between the opposite ends through a restricted opening 43. Pressure in the chamber 30 is controlled by an auxiliary valve 74 in series with the piston valve and actuated by a bellows 62 subject to the pressure in chamber 30. The outlet connection is removable to enable the sub-assembly to be removed as a whole for servicing. As shown, the housing includes a valved connection 23 for an equalizing line from the expansion valve of the refrigeration system to the inlet connection, and a second valved connection 10 to the space surrounding the sub-assembly, for an oil bleed line from the evaporator to withdraw a mixture of refrigerant and lubricant liable to collect in the bottom of the evaporator. The bellows has been evacuated through a tube 67 closed by a pinch 68 and sealed by a blob 69. The piston carries an inlet screen 37.