GB688901A - Improvements in or relating to valves for the control of fluids - Google Patents

Abstract

688,901. Stuffing-box substitutes. BLAKEBOROUGH & SONS, Ltd., J. (Dahl, E. T.). April 16, 1949, No. 10247/49. Class 122(v) [Also in Group XXIX] A diaphragm valve actuating unit comprises a diaphragm 9 mounted in a casing 1 to form a pressure chamber therewith to which fluid pressure can be admitted, a reciprocating stem 2 connected to the diaphragm, a sleeve 47 surrounding the stem, a spring 4 surrounding the sleeve and located between a nut 46<SP>1</SP> on a threaded portion of the sleeve 47 and a bridge 26 located axially in a barrel 3 depending from the casing 1 and enclosing the spring and its locating means, and sealing means between the barrel 3 and the bridge 26 and between the interior of the barrel and the diaphragm. A sealing ring 29 of neoprene or other elastic material is compressed in a recess in the periphery of the bridge 26 by a disc 30 held axially by a spring locking ring 24. One end of a bellows 31 of rubber or a light, strong fabric coated with an elastic material is cemented or clamped to the vertical face of a boss 36<SP>1</SP> formed on the disc 30, the other end of the bellows being similarly held on a further disc 33 mounted on the stem 2 and sealed thereto by a neoprene sealing ring 34. The bellows 31 is reinforced by an internal helical spring 32. The diaphragm 9 divides the casing 1 into two pressure chambers 7, 8 and, as shown, the stem 2 which is connected at its lower end to a valve stem 43 is lifted by admitting fluid pressure to the lower chamber 8 and returned by the spring 4. If desired, the unit may be operated in a reverse manner by supplying fluid pressure to the top chamber 7 and locating the spring 4 between a member 40 secured to the lower end of the barrel 3 and moving the nut 461 and a thrust button 48 to be between the spring and the bridge 26; the stem is then lifted by the spring and returned by the fluid pressure.