The Son La Hydropower project, located on the Ðà River in It Ong, Muong La District, Son La Province, is the largest hydropower dam in Southeast Asia. With dimensions including a length of 961.6m (3300ft), a crest height of 228m (748ft), a bottom width of 105m (304ft), and a crest width of 10m (33ft), the dam boasts a total installed capacity of 2400MW and an average annual electricity output exceeding 10 billion kWh through its six Francis-type turbines.
Delta Marine & Industries, Thordon's authorized distributor in Vietnam, collaborated with end user Vietnam Electricity (EVN) to find suitable replacements for the original metal polymer lined bearings. The retrofit included ThorPlas-Blue wicket gate and linkage bearings with washers, Thordon SXL operating ring wear pads, Thordon Thor-Flex wicket gate seals, and SXL upper and lower gate seals.
Johnny Dao, Managing Director of Delta Marine & Industries, highlighted that Thordon's hydro turbine bearings and seals are designed to effectively replace worn components in challenging environments like those at Son La. “Thordon’s grease-free bearing products for hydropower installation combine a very low coefficient of friction with low wear in abrasive water environment and high resistance to shock loading and vibration. They offer high pressure performance and resilience, as well as extremely long wear life,” he said.
Axel Swanson, Thordon Bearings' Business Development Manager - Hydro, Pump & Industrial, emphasized the importance of finding a sustainable solution due to the premature failure of the original parts at Son La. “It was important to them that our products could perform well in the unique challenges of the application, as the high shock load of the existing wicket gates’ operating ring that had destroyed the existing wear pads. The original seals had also hardened after a few years, leading to cracks and leaks,” he explained.
Thordon's solution involved using Thor-Flex and Thordon SXL for gate seals, SXL for operating ring wear pads, Thorseals as replacements for rubber seals, and ThorPlas-Blue for intermediate bearings.
The successful operation of the new bearings and pads at the Son La Hydropower plant over the past four years has demonstrated their reliability and durability. Delta Marine & Industries is now planning to expand the use of Thordon products to the remaining turbines at the dam.
