GRIFO CON REGISTRO GIRATORIO ESFERICO

摘要

A ball valve has a movable upstream valve seat with a metal lip engageable with the valve ball under pressure generated by a bellows section or metal membrane connected between the movable valve seat and the housing. The force of fluid pressure against this moveable valve seat is relieved by operation of a bypass valve connecting opposite sides of this seat. The ball can also have a deformable metal lip.