Patent ID: 6557645
Filing Date: 2003-05-06
Classification: A62C,F16K,Y10T

Abstract:
A differential-type dry pipe valve for a fire protection sprinkler system, comprising:a valve body defining an inlet and an outlet, a water-side chamber in communication with said inlet and an air-side chamber in communication with said outlet, and, therebetween, an air valve seat having an air valve axis and a water valve seat having a water valve axis, a clapper mounted to pivot about a pivot axis closely adjacent said air valve seat between a first, clapper-closed position for resisting flow of water through said water valve seat and a second, clapper-open position for permitting flow of water through said water valve seat toward said air-side chamber, an air valve seal mounted for sealing engagement with said air valve seat with said clapper in said first, clapper-closed position, and a water valve seal mounted for sealing engagement with said water valve seat with said clapper in said first, clapper-closed position, said air valve seat defining a center axis of system air pressure at a first radial distance from said pivot axis, measured in a plane passing through said pivot axis and perpendicular to an axis of flow between the inlet and the outlet, and said water valve seat defining a center axis of system water pressure at a second radial distance from said pivot axis, measured in a plane passing through said pivot axis and perpendicular to the axis of flow between the inlet and the outlet, said first radial distance being greater than said second radial distance.