GB251161A - Improvements in and relating to stop valves - Google Patents

Abstract

251,161. Graham, J., and Auld & Sons, Ltd., D. Sept. 3, 1925. Valves controlled by pilot or relay valves.-A stop valve of the type opened by the pressure of the fluid on the valve d and the operation of a regulating screw h and closed by the regulating screw or in emergency by the operation of an actuating valve to admit pressure fluid to a cylinder f to act on a piston g carried by the stop valve spindle e, is so constructed that on opening the stop valve fluid leaks to both sides of the piston g and is provided with a pair of spring-loaded lift valves m, p, Fig. 3, arranged in alignment within a single valve chest, which lift valves m, p together form an actuating valve on operation of which fluid under pressure acts directly on one side of the piston g while the other side is opened to exhaust whereby the piston g forces the valve d to its seat. The valves m, p are opened by a lever s so putting chambers i<1> supported from the inlet side of the stop valve and i<4> open to exhaust in communication with the outer and inner sides of the piston g to close the stop valve. The cylinder f is fitted with a liner g<6> and at the inner end with a sleeve g<3> having leaky bushes g<4> through which the valve-spindle e passes. The valve spindle is of reduced diameter at its outer end to fit in the bore of the regulating screw h.