BEARING PROTECTION
July 1st 2004

James Walker claims field trials of its new high efficiency Walkersele Ultraglide rotary lip seal on a hot steel mill show that it protects bearings for well over 18-months with no obvious signs of wear or damage.

The seals success is attributed to a hydrogenated nitrile (HNBR) elastomer developed specially for lip seals that run for long periods under hot abrasive conditions.

The new grade of material can work at temperatures in excess of 150C without hardening and cracking. It is also said to have three times the wear resistance of nitrile and twice that of fluoroelastomer (FKM) compounds often used for rotary sealing duties to 200C.

The company says that, with a low coefficient of dynamic friction at 0.25, less heat is generated at the sealing lip than with conventional nitriles and fluoroelastomers that have a coefficient around 0.40.

Other benefits claimed include a 40% better thermal conductivity that the other materials and a broad range of chemical tolerances and weatherability.

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