Backflow prevention device

Claim 1

A backflow prevention device for use in fluid conduits having an inlet opening and a longitudinally extending surface proximate thereto comprising: (a) a first member having a fluid inlet, a fluid outlet and an edge portion circumscribing said fluid outlet; (b) connector means for removably connecting said first member to the fluid conduit proximate the inlet opening thereof; and (c) valving means disposed intermediate said edge portion of said first member and said inlet opening of said fluid conduit for permitting free flow of fluids into said inlet opening but blocking fluid flow in the opposite direction, said valving means comprising a valve member including: (i) an annular portion; (ii) a body portion having a yieldable deformable, generally cylindrically shaped wall connected to and extending generally perpendicular away from said annular portion, said walls having an inner surface and an outer surface, said outer surface being normally disposed in close engagement with said longitudinally extending surface of said fluid conduit; and (iii) a yieldably deformable tongue portion having spaced apart edge portions interconnected with said inner surface of said walls of said body, said tongue portion having inner and outer surfaces, a portion of said outer surface being normally disposed in close engagement with said inner surface of said walls to prevent fluid flow in a first member, said portion of said outer surface of said tongue being yieldably deformable in response to fluid pressure to a position spaced a part from said inner surface of said walls to permit fluid flow in a second direction away from said fluid inlet of said first member.