High temperature valve stem packing with coiled graphite seal rings

Abstract

A high temperature valve stem packing incorporates a plurality of graphite seal rings composed of spirally coiled graphite tape and metal packing adapter rings being interposed between respective ones of the graphite seal rings. The metal packing adapter rings are of such configuration as to cause structural deformation of the end surface portions of the graphite rings to thereby induce the graphite seal rings to maintain the sealing capability thereof in response to wear during use and in response to fluid pressure applied thereto. In one form of the invention, the packing adapter rings are of solid construction and in another embodiment, the adapter rings are composed of pairs of interfitting rings which cooperate to define packing rings that are capable of yielding in spring-like manner as mechanical force or pressure induced force is transmitted to the packing assembly.

Dependencies are inferred from the claim text.