Patent ID: 9464729
Filing Date: 2016-10-11
CPC Classification: F16K,G05D

Claim Text:
1. A valve assembly comprising: a body having a passageway connecting a first port and a second port; a tapered annular plunger located within an annular orifice, the plunger configured to move a valve head to close and open the passageway between the first port and the second port; a pressure balancing passageway within the plunger configured to transfer a first pressure from the first port to a plunger stem cavity; and a thin annulus located between the plunger and a side wall of the annular orifice, the thin annulus providing a pressure drop passageway between the plunger stem cavity and a second cavity having a second pressure associated with the second port when the valve is in a fully closed stationary position, the thin annulus having a tapered angle created by an angle of the tapered annular plunger and a ninety degree angle of the side wall of the annular orifice when the valve is in the fully closed stationary position, and wherein a leak path from the first port through the pressure balancing passageway to the second port is not sealed to reduce an amount of friction on the plunger as it moves.