Hydrant shear valve and method

A hydrant shear valve for a hydrant coupled in fluid communication with a hydrant water supply pipe having a pipe flange, comprising:

• a valve body having fastener receiving openings for mounting the valve in fluid communication between the hydrant and the water supply pipe;
• the valve body having a valve seat;
• a two-piece valve member including two separate valve member portions each separately and independently pivotally mounted in the valve body to move independently between an open position and a closed position;
• the separate valve member portions being disposed overlapping one another axially aligned within the valve body in the open position and being disposed in a coplanar configuration in engagement with the valve seat in the closed position;
• bias members for maintaining releasably the valve member portions in the open position and for permitting the valve member portions to be moved toward the closed position under a force of fluid flowing from the supply pipe;
• wherein bias members are held down by the hydrant in a plurality of valve body recesses when the two-piece valve member is disposed in an open position and are permitted to move freely when the hydrant is at least partially dislodged from the valve body;
• at least one actuator for freeing the bias members to permit the valve member portions to move independently toward the closed position under the force of fluid under pressure from the supply pipe when the hydrant is hit with sufficient impact;
• and
• such valve member portion having an outer surface and an inner surface being disposed at an angle therebetween in cross section to direct fluid from the supply pipe around the valve member portions when disposed in an open position, the radii of curvatures of the outer surface being between about 5 inches and about 100 inches.