Mks Instruments, Inc.

Steven M King

Richard A Benson

Richard D Ericson

A chemically-resistant fluid control valve is disclosed generally comprising fluid inlet and outlet passages separated by fluid control means, which control means comprise a flapper plate disposed in the fluid passageway and mounted on a rotatable shaft that passes laterally through the fluid passageway by means of releasable fasteners adapted to engage correspondingly-shaped fastener elements of the flapper plate, which elements are also adapted to receive the shaft in a channel between the fastener elements, wherein at least all wetted surfaces of each of the several components consist essentially of a chemically-resistant material.

Chemically-resistant fluid control valves

An improved control and shut off valve assembly is disclosed. The preferred valve assembly provides sufficient forces to overcome biasing forces so as to provide adequate shut off at a leakage rate of less than 10.sup.-9 std cc/sec of He with an atmospheric differential of Helium applied across the valve seat of the assembly, and precise control of the flow rate, all as a function of a single electrical control signal. In accordance with another aspect the valve seat is made from a material softer than the valve seat engagement means so that the seat is coined by the valve seat engagement means when first used so as to insure tight tolerances for sealing the valve passageway during the shut off mode. Finally, in accordance with yet another aspect of the invention, the valve assembly is constructed with no separate parts within the flow path so as to maintain a clean passageway.

Growing community of inventors

North Grafton, MA, United States of America

Steven M King