Gate valve

In a gate valve assembly, two hollow housing members having coaxial cylindrical passages rigidly secured together end to end with axial spacer means between them defining a relatively narrow transverse gate receiving and guiding space disposed normal to said passages, sleeve units comprising annular bodies of greater axial length than said space lining each of said passages and having at one end annular resilient end lips that in the valve open position extend through said space into sealing engagement with each other, a reinforcing ring enclosed within each of said sleeves radially outwardly of its associated lip on the sleeve end, each of said lips projecting axially beyond its associated ring, a gate member having an imperforate portion slidable in said space between a valve closed position wherein it blocks flow through said valve and a valve open position wherein it permits unobstructed flow through said valve, said lips being sufficiently resilient to permit sliding movement of the gate member between said positions and being compressed in resilient sealing engagement with the sides of said gate member in the valve closed position, each of said sleeve bodies having its radially outer periphery formed to intersect with its gate engaging end in a rounded continuous surface, each of said reinforcing rings being positioned approximately equidistant from the radially outwardly surface and the axially inwardly surface of the respective sleeve body and wherein the size of each of said reinforcing rings in cross section is such that the axial length of each of said rings is about 1/4 to 1/3 the axial length of the respective sleeves body, and with the radial dimension or thickness of each of said rings being about 1/5 to 1/4 the radial thickness of the respective sleeve body from the inside diameter to the outside diameter of said sleeve body, whereby the inner faces of said sleeve bodies axially inwardly of the respective reinforcing rings are forcibly moved away from each other as the gate moves to a closed position, thereby increasing the axial compression in said sleeve bodies.

A sleeve subassembly for a gate valve passage comprising an annular sleeve body of resilient material having an annular passage engaging outer periphery and an end that is to be adjacent the gate provided with a reinforcing ring in the form of a shaped annulus of thin wear resistant material consisting mainly of a peripheral band section enclosed within the sleeve body adjacent the outer periphery of the sleeve body, and an integral annular seal lip on said body end disposed radially inwardly of and projecting axially inwardly beyond said ring, the radially outer periphery of said sleeve body being formed to intersect with said body end in a rounded continuous surface, wherein said reinforcing ring is positioned approximately equidistant from the radially outwardly surface and the axially inwardly surface of the sleeve body and wherein the size of said reinforcing ring in cross section is such that the axial length of said ring is about 1/4 to 1/3 the axial length of the sleeve body, and with the radial dimension or thickness of said ring being about 1/5 to 1/4 the radial thickness of the sleeve body from the inside diameter to the outside diameter of said sleeve body, whereby the inner face of said sleeve body axially inwardly of the reinforcing ring is forcibly moved axially outwardly as the gate moves to a closed position, thereby increasing the axial compression in said sleeve body.