Valve that is normally closed in the free state

Abstract

A valve system comprising a valve design in which the valve is normally closed is disclosed. The normally closed valve can comprise a circular valve seal face formed by the underside of a rim of an elastomeric valve boss and a circular valve seat, which is formed by the rim of a through-hole molded into, for example, a plastic cassette, such that the valve seal face, the valve seat, and the through hole are concentric. The valve boss can be a hollow “mushroom” shaped valve boss, or a conical-shaped valve boss. If no force is applied to the inside surface of the valve boss, no fluid can pass through the valve as the valve seal face rests against the valve seat as a result of the steady free-state load created by the stretch of the valve boss over the slightly longer through hole. When a force is applied to the inside surface of the valve boss, the valve seal face is displaced from the valve seat, allowing fluid between the valve seal face and valve seat and then to pass between the valve boss and the inside surface of the through hole.

Dependencies are inferred from the claim text.