Thordon Bearings has successfully tackled a persistent water leakage problem at Manitoba’s Limestone Generating Station with its innovative SXL shaft seals. The upgrade, implemented in early 2021, has reduced leakage by 70% and eliminated costly maintenance downtime for the facility.

The 1300MW power station, located 750km north of Winnipeg, relies on 10 propeller-type turbines powered by the Nelson River. Since its commissioning in 1992, the plant faced annual replacements of carbon graphite shaft seals, each requiring a week-long shutdown and causing significant financial strain.

In 2021, Thordon replaced the carbon graphite seals on one of the 133 MW turbines with SXL shaft seal segments. The results were immediate: leakage dropped dramatically, restoring operational efficiency. Thordon’s SXL seals are expected to last over 10 years – five times longer than the previous seals.

New three-ring radial seal

The new three-ring radial seal design uses just 18 segments, half the number in the original configuration. Its innovative layout directs high-pressure water flow between the rings, acting as both a coolant and a barrier against abrasives. Thordon also provided a water conditioning system to ensure a steady supply of clean water to the seals.

“Prior to our involvement, other companies had looked at the situation and just done more of the same,” said Greg Auger, Commercial Director at Millstream Engineering, Thordon’s distributor for hydropower clients in Ontario and Western Canada. “Without the superior performance offered by SXL, the problem would have remained unsolved.”

Thordon’s SXL technology has a proven track record in hydropower applications. “With our in-house engineering, we have ensured optimized designs that maximize the performance of our proprietary SXL material,” explained Ryan Edmonds, Thordon’s Business Development Manager for Hydro & Industrial.

The SXL seals can handle pressures over 0.7 MPa (100 psi) and are compatible with shafts up to 3900mm in diameter. Their modular design allows for easy installation and maintenance without removing major components—a key advantage for reducing downtime.

“Thordon’s design capabilities and 40-plus years of hydro-turbine experience ensure that a fully engineered solution is always provided,” Edmonds added. “Our seals offer superior wear resistance, long life, and lower maintenance costs, resulting in significantly reduced lifecycle expenses.”