GB700985A - Improvements in and relating to packless valves - Google Patents

Abstract

700.985. Valves. FORTUNE, R. Aug. 15, 1951 [Sept. 22, 1950], No. 23270/50. Class 135 A valve comprises a body A, Fig. 1, with inlet and outlet 10, 11 respectively, a seat 22, a closure member 73 co-operating with the seat and actuated by a stem 42, and a sealing diaphragm 17 backed by a protecting shield 16 thinner than the diaphragm and made of material more resistant to corrosive fluids and of less resilience than the diaphragm. The diaphragm and shield are clamped peripherally between the body and a bonnet B, and centrally between a follower plat( 25 and the closure member by a screw 27, a sleeve 30 limiting the compression applied by the screw. In the open position of the valve, the diaphragm and shield are supported by ribs 55 on the bonnet and are held thereagainst by the upper convex surface 24 of the closure member. In the closed position of the valve, the diaphragm and shield are supported by the convex surface 61 of the follower plate; which has slots to accommodate the ribs thereby preventing twisting of the diaphragm. The closure member seating surface 75 may be spherical, conical or cylindrical. The follower plate has slots 40, Fig. 5, engaged by a tongue 44 on a collar 43 of stem 42 and the collar operates between a surface 54 of a thimble 45 screwed to the plate 25 and the spherical upper surface 51 of the plate. The stem 42 engages threads in a nut 62' rotatable in the bonnet by a handwheel 64 or pneumatic, mechanical or electrical solenoid means. The diaphragm may be formed of heat resisting material reinforced by woven fibre glass fabric, and the shield may be produced from metallic sheet, e.g. beryllium or titanium, or from a polymer of trifluorochloroethylene or polytetrafluoroethylene. Specifications 652,564, 701,026 and 701,027 are referred to.