GB543951A - Improvements in valves - Google Patents

Abstract

543,951. Fluid actuated valves. DILLMAN, E. J., and COWLEY, W. E. Dec. 3, 1940, No. 17191. [Class 135] In an expansion valve, for refrigerating apparatus, having an element responsive to the vapour pressure of a liquid in a bulb element, the warm liquid refrigerant entering the valve casing is utilized to maintain the vapour pressure responsive element at a higher temperature than the bulb element. As shown, the casting 1 has an upper portion 3 and valve casing 4 separated by a narrow neck 2 which prevents the flow of heat from the portion 3 to the casing 4. Warm liquid refrigerant enters the part 3 at 12 and passes to the valve port 15 via a circuitous path in the part 3 and ducts 13b, 13. To the part 3 is secured a diaphragm 50 having deflection limiting plates 51, 52, on opposite sides. Rods 61 connect the diaphragm 50 to a slidable valve carrier 27, the clearance around the rods 61 allowing the space 65 below the diaphragm to be subjected to the gas pressure existing on the outlet of the valve 36. The space 66 above the diaphragm is connected to a bulb 67 which is subjected to the evaporator temperature. The coned valve element 36 is rendered self-centring by being fixed to a sleeve 32 having a radial flange 33 resting upon a flange 31 of a sleeve 29 fixed in the carrier 27. The flanges 31, 33, which are pressed together by a spring disc 40, are connected by upstanding tags 37 on flange 31 entering clearance notches in flange 33. The diaphragm 50 and carrier 27 are acted upon by springs 57, 42, the latter being adjusted by screwed member 19. The valve 36 is thus controlled by the differential pressure acting on the diaphragm 50, the chambers 65, 66, being kept warm by the liquid refrigerant flowing through space 11 of casing part 3 to prevent condensation of the vapour in the chamber 66.