Patent ID: 8327881
Filing Date: 2012-12-11
Classification: F16K,Y10T

Abstract:
1. A valve assembly, comprising: a valve body comprising an upper portion defining an upper chamber having an upper valve seat, and a lower portion defining a lower chamber having a lower valve seat, with an intermediate seat region between the upper valve seat and the lower valve seat; an upper valve stem having a flange of a larger diameter than the intermediate seat region to prevent the upper valve stem from descending below the upper valve seat movable between a closed position seated against the upper valve seat and an open position spaced apart from the upper valve seat; a lower valve stem movable between a closed position seated against the lower valve seat and an open position spaced apart from the lower valve seat; and a blocking ring disposed in between the upper valve stem and the lower valve stem, and in contact with the intermediate valve seat, wherein (i) when the upper valve stem is open and the lower valve stem is closed, fluid escaping the upper chamber impinges on the blocking ring, and (ii) when the upper valve stem is closed and the lower valve stem is open, fluid escaping the lower chamber impinges on the blocking ring.