Duckbill type check valve with curved and resiliently biased closing seal

Abstract

A check valve is provided comprising a conduit for conveying a fluid, the conduit having an inlet and an outlet, the conduit having a first region adjacent the outlet (13) comprising a flexible wall, two opposing sides of the flexible wall converging towards each other to form a closed geometry when the pressure of the fluid upstream of the inlet and the pressure of the fluid downstream of the outlet are substantially equal, the closed geometry comprising each of the opposing sides (23, 24) being arcuate in cross-section and lying against each other in a substantially sealing relationship (21, 22). Preferably, two connecting regions of the wall connecting the two opposing sides (15, 16) are biased towards each other by a biasing means. Preferably, the biasing means comprises one or more flexible ring members (25) encircling the flexible wall attached at points (25A and 25B). Preferably, the conduit takes the form of a duck beak valve (20). The figure shows an end view onto the check valve outlet.

Dependencies are inferred from the claim text.