Erosion of any sealing surface is most likely to occur when the choke is just cracking open & flow starts. In true sense to minimize the damages in the sealing area, the flow ports are not immediately exposed as the plug/sleeve moves from closed to open position. The flow dead band area allows mating surfaces of seat & plug to separate far enough so that instantaneous velocity damaged is minimized. We have the practice to manufacture trim parts that are operating at high velocity and high-pressure zone from erosion-resistant material like Tungsten Carbide or StelliteTM ST-6 or zirconia ceramics depend on the application.
JVS trim sand erosion test
A number of hole and holes sizeswere developed and designed by extensive testing on the number of variants of hole/cage geometry our in-house laboratory. Different combinations of geometry, diameter, and quantity of hole test models were tested to conclude best design approach. We developed 4 x 4 hole geometry, concentric cage multi-stage hole geometry vigorous development and sand circulation test.