Abstract: A flexible check valve for fluid-handling systems that prevents reverse flow but allows downstream flow of fluid comprises a dome that fits within a pipe and includes a concave surface. The flexible check valve further includes a flexible seat that fits within the pipe and includes a. convex surface. The flexible seat is deformable from a closed position, that prevents reverse flow, to an open position, that allows downstream flow, when an upstream pressure acts on the flexible seat and exceeds a downstream pressure and when, in the closed position, the concave surface of the dome is oriented downstream and the convex surface of the flexible seat is oriented upstream. A housing is connected to the dome and the flexible seat and is connectable to the pipe. A seal is formed between the concave surface and the convex surface when the flexible check valve is in the closed position.

Abstract: A flexible check valve for fluid-handling systems that prevents reverse flow but allows downstream flow of fluid comprises a dome that fits within a pipe and includes a concave surface. The flexible check valve further includes a flexible seat that fits within the pipe and includes a. convex surface. The flexible seat is deformable from a closed position, that prevents reverse flow, to an open position, that allows downstream flow, when an upstream pressure acts on the flexible seat and exceeds a downstream pressure and when, in the closed position, the concave surface of the dome is oriented downstream and the convex surface of the flexible seat is oriented upstream. A housing is connected to the dome and the flexible seat and is connectable to the pipe. A seal is formed between the concave surface and the convex surface when the flexible check valve is in the closed position.