Diverter valve

摘要

A diverter valve for use in a pneumatic conveying system includes a valve plate and a seal plate which have juxtaposed surfaces and are supported for relative movement therebetween so as to enable alignment of an input convey line port in the valve plate between alternate discharge convey line ports in the seal plate. Annular seals are supported in seal grooves circumferentially of the ports in the seal plate and are adapted for fluid pressure biasing into sealing engagement with the opposed valve plate by means of a fluid pressure control circuit. The seals are adapted to be subject to vacuum by the pressure control circuit so as to retract the seals from sealing relation with the valve plate during shifting movement of the valve plate. The seal plate and fluid pressure control circuit are further adapted to effect fluid pressure flow across the sealing surfaces of the seals during retraction thereof so as to clean the seals while in their retracted positions. The sealing arrangement substantially reduces seal wear and thereby prolongs the life of the seals, while also reducing the force required to move the valve plate to divert material flow.