ABSTRACT
Rubbing elements in face and circumferential seals represent the most important single use for carbon in mechanical devices. In any mechanical seal, the critical area is the rubbing interface between the carbon seal nose and its mating metal or ceramic wear plate. Within the first few hours of seal operation, a transfer film should form on the mating metal or ceramic wear plate. In an operating seal there must be a dynamic balance between the rate of formation of transfer film and the rate at which it is abraded away. Chrome plate has a dense adherent oxide film which quickly builds a thick carbon transfer film. The chemical properties of the fluid being sealed play a major role in carbon grade selection. A careful designer for seal components considers the performance required, the cost of assembly, and the cost of manufacture of both the carbon and the associated components.
