Patent ID: 8196893
Filing Date: 2012-06-12
Classification: F16K,Y10T

Abstract:
1. Valve apparatus, comprising: a valve body enclosing a fluid flow chamber, wherein said valve body has an inlet port for flow of fluid into the fluid flow chamber, an outlet port for flow of fluid out of the fluid flow chamber, and a valve bonnet that closes an end of the valve body; a closure member mounted from the valve bonnet and positioned in the fluid flow chamber between the inlet port and the outlet port, said closure member being movable back and forth between (i) a open position in which the closure member allows fluid flow through the inlet port into the fluid flow chamber and through the outlet port out of the fluid flow chamber and (ii) a closed position in which the closure member prevents fluid flow through the fluid flow chamber from the inlet port to the outlet port; actuator apparatus connected to the closure member for moving the closure member back and forth between the open position and the closed position; an expandable and contractible bellows surrounding a portion of the actuator apparatus that extends from the valve bonnet into the fluid flow chamber in the valve body, said bellows being connected between the valve bonnet and the closure member in a manner that forms and maintains a vacuum-tight seal between the actuator apparatus inside the bellows and the fluid flow chamber outside the bellows as the closure member moves back and forth between the open position and the closed position; and a cup-shaped corrosion shield extension from the closure member that surrounds the bellows and moves with the closure member toward and away from the valve bonnet as the closure member moves back and forth between the open position and the closed position, wherein said corrosion shield includes a seal that moves into a sealing position in relation to the valve bonnet that isolates the bellows inside the corrosion shield from the fluid flow chamber outside the corrosion shield when the closure member is moved into the open position.