GB548631A - Improvements in and relating to fluid controlling valves - Google Patents

Abstract

548,631. Valves. SAUNDERS VALVE CO., Ltd., and SUTTON, F. April 9, 1941, No. 4705. [Class 135] A valve of the kind in which during opening and closing there is a transverse movement of the obturating member in relation to one or more ports and incorporates resilient material which when the valve is closed extends across some part of the fluid passage but under the effect of volume compression seals the inlet from the outlet, has shields of rigid material supported by the resilient material positioned to cover the port or ports in the closed position of the valve and so prevent bulging of the resilient material. Fig. 1 shows the invention applied to a pluggate valve of the type described in Specifications 502,795, 505,974 and 513,692. The valve casing 1 has a through-way passage gradually changing in cross-section from circular at the flanges to rectangular at the seating faces with a flat part 6 immediately below the valve member. The valve member reciprocates in a circular chamber arranged at right-angles to the fluid passage and comprises a hollow core 7 with a rounded bottom 7a covered with resilient material 9. Rigid shields 10 of a size adapted to overlap the ports 4 when the valve is closed are mounted on the outside of the resilient material. The core and shields have projecting lugs penetrating into the resilient material to enable the three parts to move as unit while permitting a certain amount of relative movement. In the form shown the cylindrical chamber is formed in a sleeve clamped by tie-bolts 27 between the casing and a bonnet 20. In a modification the cylindrical chamber is formed integrally with the casing and the bonnet is split and clamped in place by a transverse bolt. Packing rings 14 are clamped between a flange 13 on the core and a washer 15 by a nut 16 screwed into a boss on the core. When the valve is fully open the washer contacts a shoulder on the bonnet to increase the pressure on the packing. The valve is actuated by a nut 21 provided with a handwheel 23 and rotatably mounted in the bonnet. This nut co-operates with a screw secured to the core and held against rotation by flats 24 on the screw engaging similar flats in an aperture in a key-plate held in slots in the bonnet. To ensure the parts being assembled in one of two positions spaced 180 degrees apart dowel pins 28 project radially from the sleeve and engage alternative grooves 29, 30 in the casing and bonnet. In the modified form the transverse bolt fits into one of two shallow grooves in the casing a grub screw being passed through the bottom into the other shallow groove. Fig. 6 shows the invention applied to a rotary cylindrical valve in which the plug 42 rotates in a resilient liner 40 held against rotation by a projection engaging a recess in the casing. The liner, which is axially compressed by a screwed plug and has bushes 44 surrounding the ports. The shields 45 are inserted in the liner and are held in position by lugs 46 so that when the cock is closed they overlap to the ends of the passage in the plug and so prevent the liner bulging into the passage. The resilient material may be natural or synthetic rubber composition, cork or resilient asbestos composition. The shields and bushes are of the same material as the valve casing.