Patent ID: 8459298

Claim:
A check valve for deterring intrusion into drain pipes comprising: a generally inverted U-shaped body member having an orifice adaptable to mount securely within an exit opening of a drain pipe, wherein the drain pipe is adapted to promote fluid flow in a single direction; a valve member pivotably mounted on said body member so as to provide a closed position that substantially occludes said orifice and a range of open positions when said valve member is pivoted to open in said flow direction; wherein the mounting of the valve member is oriented such that the force of gravity promotes the valve member toward the closed position; and wherein the mounting of the body member within the exit opening of the drain pipe is enabled because two end portions of the U-shaped body member exhibit enough outward mechanical pressure on an inside surface of the drain pipe to securely retain the body member in its mounted position during normal conditions of drainage flow or backpressures.