Patent ID: 8875733

Claim:
A backflow prevention device, the backflow prevention device comprising: a housing defining a water flow stream; an upstream shutoff valve, wherein the upstream shutoff valve is configured to allow a user to control the water flow stream through the housing; a check valve module: located within the housing downstream of the upstream shutoff valve; and including: an orifice, wherein the orifice is configured to allow the water flow stream through the check valve module; a clapper, wherein the clapper is configured to: allow the water flow stream through the orifice when open; and prevent the water flow stream through the orifice when in a closed position by mating with the orifice; a fulcrum apparatus about which the clapper is allowed to rotate; a rotational constraint apparatus which directs the rotation of the clapper; and a lateral constraint apparatus constrains the fulcrum apparatus to move upstream and downstream relative to the orifice; a downstream shutoff valve: located downstream of the check valve module; and configured to allow a user to control the water flow stream through the housing.