| 摘要 |
<p>A check valve having a body with an inlet, an outlet, a valve seat surrounding communication between said inlet and said outlet, a valve chamber in said body communicating with said outlet, a bonnet having a cylinder therein with the open end communicating with said valve chamber where the bonnet is secured to said body, a valve disc resiliently secured to an arm which is pinned to allow the valve disc to be pivoted from a position engaging said valve seat to a position in said valve chamber, a piston in the bonnet cylinder and having a connecting rod secured to said valve disc arm so that said piston reciprocates in said cylinder as said valve disc moves, a port through the piston to allow passage of the fluid flowing through the check valve to flow to opposite sides of the piston as it reciprocates in the cylinder, a reed valve secured to said piston and adapted to substantially close said port during closing movement of said valve disc but allow relatively free flow of fluids through said port during opening movement of the valve disc, a seal ring having sufficient resiliency and being contoured to provide a seal between said piston and said cylinder during reciprocation and tilting of said piston within said cylinder, all moving parts being contained within said valve body and said bonnet, said piston and said valve disc having substantially the same diameter to cancel out effects of back surge.</p> |
