GB797375A - Rotary valves - Google Patents

Abstract

797,375. Valves. HALE FIRE PUMP CO. Sept. 23, 1955 [Dec. 13, 1954], No. 27158/55. Class 135. In a valve having a part spherical valve element 14, Fig. 2, rotatably mounted on an integral trunnion 15 and stem 16 passing through the casing 10 and its cover 17 respectively, the casing is formed with a counterbore 40 housing a resilient sealing ring 41 and with clearance an axially movable two-part seat member 36 fitted with a resilient seating ring 38 engageable with the valve element. Regardless as to whether a port 12 or a port 13 is the valve inlet, pressure fluid enters the counterbore 40 to distort the ring 41 to form an effective seal when the valve is closed. In one instance, pressure fluid enters the counterbore through the clearance between the bore and the seat member to seal the space around the tail 38c, Fig. 8, of the seat member and in the other instance pressure fluid enters the space around the tail to seal the clearance. In each case the projected area of the rear end of the seat member 36 exposed to fluid pressure is greater than the frontal area thereof so exposed so that the seat member and its ring 38 are always urged by fluid pressure against the valve element. The valve is operated by a rod 21 which passes through the stem 16 and a split sleeve 24. To lock the valve element in any desired position the rod is rotated about its own axis whence screw threads on the rod and in the sleeve clamp the sleeve against the stem. A large diameter opening 11 in the casing permits easy access for servicing the valve parts without removal of the valve from the pipe-line.