High strength ball valve seat assembly

摘要

A ball valve for low and high pressure applications including a metallic seat member that toroidally deflects into sealing engagement with a ball member outer surface upon valve assembly. The seat member includes an outer circumferential rim portion and a radially inward extending frusto-conical portion. The rim portion is radially interposed between an annular, resilient flange member and an annular support member. The rim portion and resilient flange member define a behind-the-seat seal while the frusto-conical portion and support member abuttingly engage during extreme pressure conditions for added structural support. The radially innermost edge of the frusto-conical portion has an arcuate conformation to inhibit scoring of the ball member surface.