Patent ID: 9206919
Filing Date: 2015-12-08
Classification: C23C,F16K,Y10T

Abstract:
1. Manifold valve apparatus for selectively directing a fluid flowing in a foreline to a plurality of foreline branches, comprising: a manifold valve body enclosing a manifold valve chamber, wherein said valve body has an inlet port adapted for fluid-flow connection to the foreline for conducting a flow of fluid into the manifold valve chamber and a plurality of outlet ports adapted for fluid-flow connection to respective foreline branches for conducting flow of fluid out of the manifold valve chamber; a plurality of closure members, each of which closure members is positioned in the manifold valve chamber between the inlet port and a respective one of the outlet ports and is movable back and forth between (i) an open position in which the closure member allows fluid in the manifold valve chamber to flow through the respective outlet port and out of the valve chamber and (ii) a closed position in which the closure member prevents fluid flow through the outlet port; actuator apparatus for each of the closure members for moving each of the closure members respectively back and forth between the open position for the respective closure member and the closed position for the respective closure member, the actuator apparatus being of a type comprising a piston for applying a force to move the closure member in one direction, a spring for applying a force to move the closure member in an opposite direction, and a bellows positioned to isolate the manifold valve chamber with an vacuum-tight seal from the piston; a plurality of expandable and contractible shields positioned in the valve chamber in a manner such that at least the bellows of each actuator apparatus is surrounded by one of the expandable and contractible shields in a manner that separates at least the bellows from gases flowing in the valve chamber and encloses a space around the bellows; and a plurality of gas ducts that are connectable to a positive pressure gas supply outside of the valve chamber and extend to respective ones of the spaces around the respective bellows that are enclosed by the respective expandable and contractible shields for directing positive pressure gas into the spaces around the bellows that are enclosed by the expandable and contractible shields to maintain the spaces at a pressure higher than a pressure in the valve chamber outside of the shields.