Trelleborg Sealing Solutions has introduced a range of mechanical face seals in cast oron or bearing steel for rotating applications in extremely arduous environments. The products comprise two identical metal sealing rings mounted in two separate housings, face-to-face on a lapped seal face. The metal rings are centered within their housings by means of O-Rings or elastomers with a diamond-shaped cross section. One half of the mechanical face seal remains static in the housing, while the other half rotates with its counter face. Cast iron versions will operate at speeds of up to 3 m/s with oil lubrication, while bearing steel versions will cope with rotational speeds of up to 2.2 m/s.
The elasticity of the O-Rings or elastomer rings generate a uniform axial face loading for the metal rings as well as acting as static seals on the inner and outer diameter. They also prevent the metal seal ring on the static side of the metal face seal from turning within the housing and transmit the torque from the rotating half of the housing, through the faces, to the static half.
Temperature resistance is dependent upon the type of elastomer used within the seal. A choice of Acrylonitrile Butadiene Rubber (NBR), Hydrogenated Nitrile Butadiene Rubber (HNBR), Fluoroelastomer (FKM) or Silicone (VMQ), provides an operating range between -40°C to +200°C. These compounds also provide a high degree of chemical resistance.