Abstract: The invention is a film-riding seal for a pump shaft that is resistant to the deposition of iron oxides such as hematite and goethite on the confronting, spaced apart, seal surfaces. The seal generally comprises a ceramic runner mounted on the pump shaft and an adjacent ceramic stationary sealing ring. The runner has a sealing surface and the stationary sealing ring has sealing surface confronting the runner sealing surface. The ceramic sealing surfaces include a catalyst selected from the group consisting of rhenium, ruthenium, rhodium, palladium, silver, osmium, iridium, platinum, gold and mixtures thereof.

Abstract: A pump has a shaft and a housing containing pressurized fluid and employs a rubbing-type sealing assembly for sealably and rotatably mounting the shaft within the housing. The sealing assembly includes an annular runner mounted around the shaft for rotation therewith and an annular seal ring mounted within the housing in non-rotational relationship thereto. The runner and seal ring have surfaces facing and in rubbing contact with one another. A coating of titanium nitride is incorporated on at least one of the surfaces. The coating of titanium nitride can be deposited as an outer hardface layer on the one surface, or, alternately, as an inner passivating barrier layer upon the one surface and then a coating of chromium carbide can be deposited as an outer hardface layer on the coating of titanium nitride.