Durban-based rotating-coupling alignment specialist Alignment With Laser (AWL) is supplying State-owned power utility Eskom with two sets of 1 100-mm-diameter Thordon SXL segmented shaft seals, worth $30 000, for use on a trial basis on one of its four hydro turbines at the Dakensberg pumped-storage scheme.
The company was awarded the South African agency for Canada-based nonmetallic journal bearing manufacturer Thordon Bearings last year.
AWL manager David Kirk says the tough and abrasion-resistant design of the polymer Thordon SXL segmented shaft seals reduces water leakage and enables operation in dirty and abrasive environments.
The seals are also easy to install and can withstand high shock loads and edge loading, while eliminating almost any potential for catastrophic failure that can occur with carbon graphite-based seals.
“Whenever a shaft rotates, a bearing arrangement is required for smooth, effective operation, enabling it to reach the highest possible service life and reliability,” he points out.
Thordon bearings are self- lubricating and never have to be lubricated with grease or other lubricants, says Kirk.
He notes that the company hopes to use the Eskom trial as a springboard to supplying Thordon products to the rest of Africa.
AWL is also supplying Thordon’s SXL polymer staves to a 1.2 MW hydroturbine project in Liberia, while also working with other power companies in Kenya, Zambia and Zim- babwe.
The company is focused on supplying the Thordon bearings and accessories range to the hydropower market and has noted a steady increase in demand in the bearings market, as is reflected in its sales figures for the bearings range.
AWL has experienced some resistance to the sale of Thordon bearings in South Africa, owing to the existing idea that a bush and bearing are sacrificial components that can be replaced only if needed.
“We want local companies to invest in a better product with a longer life span,” says Kirk.
AWL aims to strengthen Thordon Bearings’ brand in Southern Africa, not only in terms of its products, but also in terms of its service and after-sales offerings.