Axial flow throttling valve

Claim 1

A valve for controlling the flow of fluid therethrough comprising a body having a fluid passage therethrough and a control chamber therein, unitary cage means through which fluid may flow, mounted in said body, said cage means having a wall with first and second portions separated by a baffle, each of said portions having a plurality of openings therein for enabling fluid flow from an inlet through openings in said wall to the exterior of said cage means and from the exterior of said cage means through other openings in said wall to said outlet, said first portion extending from the inlet of said body to said baffle and having a generally cylindrical shape, and said second portion extending from said baffle to the outlet of said body and having a generally frustoconical shape, resilient boot means mounted over said cage means, said resilient boot means having a configuration substantially the same as the outer configuration of said cage means and being normally in contact with the periphery of said cage means for sealing said openings, said resilient boot means having in-turned flanges on either end, allowing insertion of said cage means into said boot means through the larger end, and providing clamping of said boot between said cage means and the end walls of said control chamber, said control chamber being an enlarged bore from one end concentric with said fluid passage, and a cover over said one end, said boot means and said cage means being seated at the other end in said enlarged bore in said body and seated at said one end in a counterbore in said cover.