New Elastomeric Axial and Radial Turbine Shaft Seals

For Immediate Release - December 7, 2007

Thordon Bearings Inc., a world leader in grease and oil-free bearing and sealing solutions, has announced the introduction of new design Thordon SXL elastomeric polymer segmented shaft seals for both vertical and horizontal turbine newbuilds and retrofits.  SXL axial and radial segmented turbine shaft seals are a direct replacement for carbon seals offering:

• Easy installation / reduced weight - will not break under impact
• Excellent abrasion resistance
• High impact / shock resistance
• Leakage rates similar to carbon seals
• Documented increased wear life (up to 25 years)

Sealing large hydro-turbine shafts from 400mm up to 2000+mm (16” up to 80”) diameter can be a maintenance challenge for power plant operators. Carbon seal rings are brittle and present significant handling and installation difficulties. In addition, their wear life can be significantly shortened if subjected to misalignment or abrasives in the water or operational transients.

Since its first turbine shaft seal installation in 1982 at the Manapouri Power Station in New Zealand - which is still in service - Thordon Bearings has compiled a history of segmented shaft seal installations. In 2003, Thordon embarked on a program to further optimize its segmented shaft seal design utilizing its proprietary SXL elastomeric material.  Thordon SXL is a very tough synthetic polymer alloy with performance characteristics superior to most other typical seal materials. SXL has high natural abrasion resistance and is well suited for such sealing applications. 

Thordon Bearings offers both a radial and axial seal design with unique design features for each sealing application.  Thordon SXL segmented shaft seals are currently designed to operate up to 0.7MPa (101 psi) typically using injection of clean water between the first and second ring of seals.