These are specifically engineered for rotating applications in extremely arduous environments where they withstand severe wear and prevent ingress of harsh and abrasive external media. They are available with metal parts in cast iron or bearing steel, with the bearing steel option offering significant cost savings on medium to large seals within suitable applications.
The Mechanical Face Seal, also commonly referred to as Face Seal or Heavy Duty Seal, consists of 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 most commonly by O-Rings or otherwise by 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.
“Up to 7.2 ft/s the bearing steel option, due to lower process and material costs, can offer significant savings, especially for medium to large size Mechanical Face Seals,” says Colin Macqueen, Director, Technology for Trelleborg Sealing Solutions Americas. “In addition, there is more flexibility in design, allowing the seals to be custom-engineered for specific housings.”
The metal part of the Mechanical Face Seal is available in special heat treated high-alloy corrosion-resistant mold cast iron or a forged roller bearing steel. Selection of material depends on operating conditions. Cast iron will operate in speeds up to 10 ft/s / 3 m/s with oil lubrication, while for rotational speeds up to 7.2 ft/s / 2.2 m/s, bearing steel is adequate. The elasticity of the O-Rings or elastomer rings generates a uniform axial face loading for the metal rings, and these O-Rings act 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 depends on the type of elastomer used within the seal. A choice of Acrylonitrile Butadiene Rubber (NBR), Hydrogenated Nitrile Butadiene Rubber (HNBR), Fluoroelastomer (FKM) or silicone, provides an operating range between -40°F to +392°F / -40°C to +200°C. These compounds also give chemical compatibility to virtually all media encountered in applications where Mechanical Face Seals are used.
Mechanical Face Seals are ideal for sealing in heavy duty rotating applications such as rollers, front idlers and final drives of tracked vehicles, graders, shovels, ploughs and scrapers on tractors, off highway trucks, drilling machines, hydraulic excavators, conveyors, concrete mixers, asphalt plants, mining equipment, crushing equipment, mowers, hay balers and wind turbines. They are particularly suited for fitment on axles, gearboxes, mixers and stirrers.
About Trelleborg Sealing Solutions
Trelleborg Sealing Solutions is one of the world’s leading developers, manufacturers and suppliers of precision seals. They support their aerospace, industrial and automotive customers through over 25 production facilities and more than 40 marketing companies globally. Within their portfolio are some of the longest established sealing brands, including Busak+Shamban, Chase Walton, Dowty, Forsheda, GNL, Palmer Chenard, Shamban, Skega and Stefa along with a large number of proprietary products and materials such as Turcon®, Zurcon®, Orkot®, Isolast®, Stepseal® and Wills Rings®. www.tss.trelleborg.com