Valve construction for sand and slurry service

摘要

A gate valve is provided having a recess formed in the upstream portion of the gate and in intersecting relation with the gate port. The gate recess cooperates with a registering recess formed in the downstream portion of the upstream seat to develop a large flow passage as compared to a small flow passage defined by the interrelationship of the gate port with the downstream seat. Fluid laden with erosive material will flow through the larger dimension gate/seat opening between the gate and upstream seat at low velocity, as compared to high velocity flow through the opening defined between the gate and the downstream seat. This low velocity flow, impinging upon the downstream seat, results in minimized erosion of the downstream seat during opening and closing movement of the valve.