GB610508A - Improvements in and relating to valve construction - Google Patents

Abstract

610,508. Non-return valves. BURKE, O. J. Aug. 22, 1944, No. 16025. Convention date, Oct. 20, 1943. [Class 135] A non-return and venting valve for liquid systems comprises a valve member of flexible material such as natural or synthetic rubber arranged between the inlet and outlet ends of a casing having an air port, the valve member being sealed to the casing between the air port and the inlet end and coacting under internal pressure with a succession of seals between the air port and the outlet end to effect multiple sealing off of the air port. As shown, the valve member 40, Fig. 1, is of deep cup-like form, anchored at its open end to a rigid containing casing 10, preferably of brass or other metal, and provided at its closed hemispherical end with radial self - closing slits 44, Fig. 3, strengthened by moulded ribs 50. Liquid flow from the inlet 16 passes through the slits 44 to the outlet 13, distending the member 40 and causing it to coact externally and, as the pressure increases, successively with a convex valve seat 10b, a concave seat 10a, a rib 42 and a cylindrical seat 10c thus sealing the flow passage off from the air ports 28 in the casing wall. A rigid sleeve 32 prevents the distended member 40 from fouling the ports 28, which are also protected externally by the forward extension 29 of a screwed inlet coupling 15. On loss of pressure in the liquid supply system, the slits close, preventing reverse flow, whilst the valve member retracts from its sealings and allows air to enter the discharge side of the liquid system. In Fig. 1 (not shown), the threaded outer end of the inlet coupling is dispensed with, the valve member being extended outwardly to form an elastic inlet nipple connection.