Valve assembly

Abstract

A valve assembly is provided for controlling pressurized inputs from two separate fluid sources, and in particular to provide enhanced isolation between the sources and to buffer short-term fluctuations in fluid flow. A high pressure chamber is provided which is separated into two chamber portions by a fluid-impervious flexible membrane. A valve, such as a ball valve, having a movable member is positioned in an inlet port in each channel portion, fluid flowing, for a preferred enbodiment, from a fluid source under pressure through the inlet port of a chamber portion, an output port in the portion and a restrictor to a mixer. A pressure differential in the chamber portions deflects the diaphragm to bear against the movable member in the lower pressure chamber portion, closing the valve for this chamber portion before the pressure is sufficient to result in any backflow therethrough. The membrane also deflects when there are momentary breaks in the flow from one source to temporarily buffer flow from the other source, thus maintaining a substantially uniform mix ratio.

Dependencies are inferred from the claim text.