Designing mechanical seals for sealing refrigerants and other low viscosity liquids has been a difficult problem for seal manufacturers for many years. However, mechanical seals with antimony impregnated, carbon-graphite primary rings and solid silicon carbide counter face rings could solve this problem. Low viscosity liquids such as Freon refrigerants, liquid oxygen, liquid carbon dioxide, propane, ethylene, and acetone are now being successfully sealed using mechanical seals with Metcar Grade M-444, antimony impregnated, carbon-graphite primary seal rings.

Low viscosity liquids are difficult for mechanical seals because the hydrodynamic film that they create between the two rubbing seal faces is extremely thin. In order for this extremely thin hydrodynamic film to lubricate the two sealing faces, the seal faces must stay highly polished and they must run in very close proximity to each other. The M-444 antimony impregnated, carbon-graphite material and the solid silicon carbide and antimony impregnated carbon- graphite can enables these two materials to run in the required close proximity. Ordinary mechanical seals with resin-impregnated, carbon-graphite primary rings do not have the self-polishing characteristic or the dimensional stability that is required for sealing these low viscosity liquids.

Information on mechanical seal primary ring materials for other difficult sealing applications are available from Metcar’s Application Engineering Department.

About Metallized Carbon Corporation

Since its inception in 1945, Metallized Carbon Corporation has been manufacturing high-quality, dependable bearing solutions for severe operating environments. With over 50 years of Application Engineering experience, Metallized Carbon offers the field expertise and data necessary to provide The Solid Choice for Lubrication® in a wide variety of industries, supplying completely machined components as well as materials for customer machining. Metallized Carbon is ISO certified and produces the Metcar brand of solid, oil-free, self-lubricating materials.

For additional information about the company and its services, please visit Metcar online at www.metcar.com