Replaceable cartridge valve assembly

Claim 1

A replaceable valve assembly in the form of a cartridge adapted for insertion into a valve body of a sanitary fitting used for the control of water therethrough, said cartridge comprising: a cylindrical housing having an axial bore therethrough, said housing having open upper and lower ends, and a water discharge opening formed between the ends thereof; an elongated cylindrical stem rotatably mounted in said housing and having a diameter substantially equal to the internal diameter of said housing to provide a rotating sliding fit; first and second discs being in face-to-face movable contact with each other along a common plane, said first disc having at least one water passageway therethrough and adapted to be positioned at one end in fluid communication with an inlet opening in said open lower end of said elongated housing and at the other end adjacent said face of said second disc; said second disc having at least one water passageway therethrough and positioned so that relative movement between said discs will direct said at least one passageway therein between a blocked, shut-off position with the passageways being out of alignment and the partially, and completely overlapped positions where water can flow through said discs; said discs being mounted in the housing and one of said discs being connected to one end of said stem for rotation therewith; said water discharge opening of said housing having a cross-sectional area substantially equal to the cross-sectional area of said at least one passageway of said first and second discs to provide a water conduit for fluid communication between said water inlet opening and said water discharge openings in said housing; said stem and said housing cooperating to form an auxiliary valve means for throttling water flow downstream from said water discharge opening in said housing to said at least one passageway formed in said discs which together operate in a patterned, equal ratio relationship to control the volume of water flow through said valve housing simultaneously with the volume of water flow through said at least one disc passageway to provide a stepdown in pressure drop and thereby inhibit cavitation and/or other objectionable noises associated with the operation of said valve.