APPARECCHIATURA PER ALLINEARE E RITRARRE ANELLI DI TENUTA PER VALVOLE DEL TIPO A MASCHIO

摘要

A valve plug assembly for use in a steam throttle valve includes a valve body and a removable guide ring attached to one end of the valve body. An outer edge portion is removed from the guide ring at the interface with the valve body so that a circumferential groove is defined about the valve plug when the guide ring is assembled to the valve body. A slot is formed in one wall of the groove, preferably in the guide ring, and a wear ring inserted in the slot. The wear ring extends above the wall surface and terminates in an angled bearing surface. A pressure seal ring is formed with a mating bearing surface and is placed in the groove prior to assembly of the valve plug. The angular taper on the mating bearing surfaces causes some retraction of the pressure seal ring in response to sudden valve plug movement in the closed direction.