STEEL GASKET WITH INSULATING COATING AND METHOD FOR PROVIDING SAID COATING

摘要

An electrically insulating gasket for use in insulating pipe line sections comprises a mild steel O-ring having an ethylene chlorotrifluoroethylene copolymer coating which is applied by a special method to ensure intimate contact between the coating and the whole of the metal surface, with the coating being keyed into microscopic irregularities of the surface. The method involves thorough cleaning of the steel O-ring to expose white metal, etching the ring, cleaning the etchant solution from the ring, heating the O-ring to a temperature from 525.degree.F to 545.degree.F, and electrostatically applying successive layers of the copolymer coating composition to provide a coating thickness of at least 10 mil.