GB823173A - Improvements in gas pressure control valves - Google Patents

Abstract

823,173. Valves. ENFO ENTWICKLUNGSUND FORSCHUNGS A.G. Oct. 1, 1957 [Oct. 2, 1956], No. 30687/57. Class 135. In a casing 1 are disposed adjustable main and return springs 2, 3, respectively, that act upon a valve closure 8 via a spingle 5b; the closure co-operates with upper and lower valve seats 6, 7 separated by a sleeve 7a. The seat 6, which may be provided with a gasket 9, is removable and may be ground to compensate for wear; shims 7b are positioned beneath the lower seat to adjust the lift of the closure 8. Sealing rings may be associated with one or both of the seats arid associated closure surfaces, which latter may be flat or conical. The seat 7, bolted to the casing 1, incorporates an axial or as shown a radial inlet I, which may be located in any one of four positions at 90-degree intervals. Sleeve 7a embodies diametrical holes 13a, 13b of different sizes, the smaller of which 13b leads to an outlet II whilst the other opens via a throttling nozzle 14 into a passage 15; the sleeve 7a may be rotated to reduce the effective size of the hole 13b. Passage 15 discharges fluid at the rear of a return piston 18 that acts on spring 3; in the position shown a washer 22 serves as a valve closure and prevents leakage losses between the piston 18 and its cylinder 19. The return piston 18 only exerts its full effect when the closure 8 contacts the seat 6, which latter with the closure 8 in the position shown, connects the outlet II and piston 18 to atmosphere through an outlet III. When the inlet pressure lifts the closure 8 from seat 7 the spacing of the closure 8 from the seat 6, is determined by the balance between the inlet pressure and the force exerted by the piston 18 through the spring 3, such spacing controlling the effective opening between outlets II and III and hence the pressure at outlet II. The outlet III also serves as an exhaust for the fluid from piston 18 when the closure 8 moves to the position shown.