SEALING SYSTEM

摘要

A graphite packing ring for use in a gland seal is formed by applying a layer of secondary material (30a, 30b) such as PTFE or PEEK having good friction reducing and/or sealing properties to a major surface (21) of a graphite tape prior to wrapping the tape around a former and compressing in a mould to form the packing ring of a desired configuration. Minimal quantities of secondary material (30a, 30b) are required but are exposed at the key areas on the surface of the packing ring, improving heat tolerance whilst reducing manufacturing costs.