Patent ID: 8028715

Claim:
A check valve for use in a vacuum sewage pipe, said check valve comprising: a body having a sewage inlet and a sewage outlet to be coupled to the vacuum sewage pipe; a flap valve element disposed in said body and rotatably supported by a first shaft to prevent a backward flow of sewage; a pressing member coupled to said first shaft and rotatable about said first shaft independently of said flap valve element to press against said flap valve element; and a second shaft connected to said pressing member and movable inward and outward relative to said body to define an angle of said pressing member, wherein said second shaft has a thread groove capable of being engaged with a fastening member disposed on said body, and wherein said pressing member is locked at a lowermost position by engagement between said fastening member and said thread groove to keep said flap valve element in a closed state to allow said flap valve element to function as a gate valve that blocks off a flow of sewage.