Valve

摘要

A valve comprising a valve body having a bore and a plunger axially movable in the bore between an open and a closed position. The bore has a fixed valve seat therein and is in communication with an inlet port and outlet port on opposite sides of the bore seat. The plunger has a seat cooperable with the bore seat to make a leak-tight, face-to-face seal when the plunger is in its closed position. The plunger also carries a pressure-actuated "seatless" seal which seals against the walls of the bore and the plunger when the plunger is in its closed position and is subjected to system pressure.