Product category:
Seals, gaskets, bushes, etc
News Release from: James Walker and Co | Subject: Walkersele Ultraglide rotary lip seal
Edited by the Manufacturingtalk Editorial
Team on 11 June 2004
Long-life seal reduces hot mill bearings
wear
Field trials of high-efficiency 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.
Field trials of James Walker's 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 Traditional nitrile rubber (NBR) seals usually survive only three months on the intermediate stand at this Corus plant in the UK
This article was originally published on Manufacturingtalk on 12 Aug 2003 at 8.00am (UK)
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Ultraglide's success is based on a hydrogenated nitrile (HNBR) elastomer that was specially developed by James Walker Technology Centre 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, instead of 100degC maximum for traditional nitrile.
It also has three times the wear resistance of nitrile and twice that of fluoroelastomer (FKM) compounds often used for rotary sealing duties up to 200C.
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James Walker head of technology David Edwin-Scott, said: "A 241.3mm ID Walkersele Ultraglide was installed on the rolling mill to retain lubricant within a bearing and exclude water, steam, scale and rolling fluid".
"After 18 months working at speeds of 70-120rev/min, the roll chocks were removed and the seals inspected in situ".
"The Ultraglide was found to be in 'as new' condition, so the chocks were refitted without removing the seals and the trial continued".
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.
Also, Ultraglide has 40% better thermal conductivity than the other materials, so heat is dispersed more efficiently and the all-important lip retains its flexibility for high efficiency sealing.
Chemical compatibility is a further strong point for Ultraglide.
It combines the excellent resistance to oils and fuels of conventional nitrile materials, with a broader range of chemical tolerances and weatherability.
Commented Edwin-Scott: "It can take three hours to replace a worn lip seal on this type of heavy rotary plant".
"Therefore a six-fold increase in maintenance-free life can save a lot of highly costly downtime, especially when many bearings need protection".
The Walkersele Ultraglide under trial is a D6 type with its lip energised by a fully moulded-in spring.
This makes the seal easier to fit as well as ensuring that the spring is located properly for efficient sealing and cannot be dislodged.
The spring is also protected from chemical and abrasive media. Request a free brochure from James Walker and Co ...
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