초록 ▼

A check valve apparatus, usable in a double check valve backflow preventer apparatus, comprising a valve seat, a clapper pivotally coupled to the valve seat, a seal positioned to sealingly engage the clapper and valve seat when the clapper is closed against the seat, and a closure mechanism. The clo

A check valve apparatus, usable in a double check valve backflow preventer apparatus, comprising a valve seat, a clapper pivotally coupled to the valve seat, a seal positioned to sealingly engage the clapper and valve seat when the clapper is closed against the seat, and a closure mechanism. The closure mechanism includes a first linkage element pivotally associated with the valve seat at a first pivot point located upstream from the seal, a second linkage element which is pivotally coupled to the first linkage element at a second pivot point, and which is pivotally associated with the clapper at a third pivot point, and a bias element associated with at least one of the linkage elements and configured to exert a closure force on the clapper.

대표청구항 ▼

1. A check valve apparatus, comprising:(a) a valve seat having a fluid channel extending therethrough; (b) a clapper pivotally associated with said valve seat; (c) a seal positioned to sealingly engage said clapper and said valve seat when said clapper is positioned to close said fluid channel; (d)

1. A check valve apparatus, comprising:(a) a valve seat having a fluid channel extending therethrough; (b) a clapper pivotally associated with said valve seat; (c) a seal positioned to sealingly engage said clapper and said valve seat when said clapper is positioned to close said fluid channel; (d) a first closure element pivotally coupled to a mounting point located upstream from said seal; (e) a second closure element movably coupled to said first closure element and movably coupled to said clapper; and (f) a bias element associated with at least one of said closure elements and configured to exert a closure force on said clapper.