Check valve in backflow prevention device

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;
• an 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;
• and
• 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 which directs the motion of the fulcrum toward and away from the orifice;
• wherein the motion of the clapper from the closed position to the open position is a hybrid motion;
• 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.

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;
• an check valve module:
• located within the housing downstream of the upstream shutoff valve;
• and
• including:
• a seat configured to mate with a portion of the housing;
• an orifice, wherein the orifice is configured to allow the water flow stream through the check valve module;
• and
• 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;
• a lateral constraint apparatus which constrains the fulcrum apparatus to move upstream and downstream relative to the orifice;
• and
• a bias configured to hold the clapper in the closed position a predetermined upstream pressure exists;
• wherein the motion of the clapper from the closed position to the open position is a hybrid motion,. and
• 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.