GB909426A - Fluid control valves - Google Patents

Abstract

909,426. Valves. BURMAN & SONS Ltd., and BRIGGS, W. H. May 19, 1961 [May 19, 1960], No. 17646/61. Class 135. A control valve comprises a body part 10, 11, Fig. 1, having an inflow passage 12, an outflow passage 13 and at least one return flow passage 17, a spring-loaded cup-shaped closure member 18 having at its closed end an external diameter greater than that of its opposite end, a nozzle 19 in the body part 10 extending into the closure member from the inflow passage 12 and forming with the said member an annular passage through which the motive liquid can flow from the inflow passage 12 with reversal of direction to the outflow passage 13, the closure member 18 being movable against the force applied by its loading spring by means of kinetic pressure developed by liquid flowing through the valve so as thereby to establish communication between the inflow passage 12 and the return flow passage 17 or one of the return flow passages when said kinetic pressure reaches a predetermined value. An independent spring-loaded valve member 21 relieves static pressure when it builds up because of partial or complete closure of a valve of the hydraulic mechanism being actuated. The valve member chambers 14 and 15 are interconnected by a port 16 and the valve member 21 has a groove 23 so that the build up of static pressure effects closure of the member 18. In another example, Fig. 2, the valve member 21 is omitted and the closure member 18 is recessed at 27 so that it serves a dual function, being moved upwardly by the kinetic pressure of the liquid to open the return passage 17 and being moved downwardly to relieve the static pressure.