Patent ID: 9395009
Filing Date: 2016-07-19
CPC Classification: F16J,F16K

Claim Text:
1. A fluid flow control device comprising: a valve body defining an inlet, an outlet, a fluid flow path extending between the inlet and the outlet, and a longitudinal axis, the valve body having a first thermal expansion coefficient; a valve seat disposed within the valve body and defining an orifice through which the fluid flow path passes; a valve cage coupled to the valve seat within the valve body and defining an interior bore, the cage having a second thermal expansion coefficient different than the first thermal expansion coefficient; a valve plug sized for insertion into the interior bore of the valve cage and movable along an axis between a closed position, in which the valve plug engages the valve seat, and an open position; a gland defined by at least one of the valve seat and the valve cage; and a sealing assembly arranged within the gland to provide a seal between the valve body and the valve cage, the sealing assembly comprising a seal portion and a biasing element disposed immediately adjacent the seal portion, and the sealing assembly arranged in a first compression state in which the sealing assembly provides first radial and axial compression forces, the sealing assembly movable to a second compression state in which the sealing assembly provides second radial and axial compression forces greater than the first radial and axial compression forces, the movement of the sealing assembly being due to differential thermal expansion between the valve body and the valve cage in an axial direction that is parallel to the longitudinal axis and in a radial direction that is transverse to the longitudinal axis, wherein the biasing element comprises a gasket and the seal portion has a thermal expansion coefficient equal to the first or second thermal expansion coefficient, and wherein the gasket is disposed in contact with the seal portion, the gasket configured to provide the first and second radial compression forces to the seal portion to bias the seal portion outward against the valve body to provide the seal between the valve body and the valve cage.