Patent ID: 8887756

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; and includes an obstruction, wherein the obstruction: is configured to: prevent water flow at a first position; allow water flow at a second position; and rotate about an axis of rotation between the first position and the second position; and includes a seal, wherein the seal is: configured to sealingly engage a sealing surface in the housing at the first position; and wherein all points of engagement between the obstruction seal and the sealing surface are located downstream of the axis of rotation of the obstruction; an upstream check valve: 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 upstream check valve; and a clapper, wherein the clapper is configured to: allow the water flow stream through the orifice when open; prevent the water flow stream through the orifice when in a closed position by mating with the orifice; and define an axis of rotation constrained to move upstream and downstream relative to the orifice; a downstream check valve: located within the housing downstream of the upstream check valve; and including: an orifice, wherein the orifice is configured to allow the water flow stream through the downstream check valve; a clapper, wherein the clapper is configured to: allow the water flow stream through the orifice when open; prevent the water flow stream through the orifice when in a closed position by mating with the orifice; and define an axis of rotation constrained to move upstream and downstream relative to the orifice; and a downstream shutoff valve, wherein the downstream shutoff valve is configured to allow a user to control the water flow stream through the housing.