CASE STUDY | WIND POWER & ENERGY
Hydropower Unit Overhaul
A customer initially contacted us to request a quote for replacing large diameter rotary shaft seals, specifically sizes 260x300x20 and 300x340x20.
Assessment
Further conversations revealed a problem related to rising water levels and the resulting increase in water pressure. This presented some challenges, as the current rubber rotary shaft seals were only designed for a pressure of 0.5 bar and were installed back to back. With this new information, in collaboration with the customer, we decided to replace the seal.
Solution
We switched to a double-acting solid PTFE rotary lip seal (RB31). This seal is designed to handle significantly higher pressures, up to a maximum of 5 bar.
The advantages of the RB31 include its ability to handle higher speeds, pressures, and temperatures, and the requirement of just one seal due to its dual sealing lips. This eliminates the need for back-to-back seals, saving space and reducing the number of seals needed. One lip of the seal retains the grease in the bearings and prevents it from leaking into the river, while the other lip prevents river water from leaking into the bearings.
This was then immersion tested at our test facility in a saline solution to prove its suitability in the high salt content.
Result
We designed and manufactured the parts within just one week, compared to the usual 6-week lead time for standard rotary shaft seals. The seals were manufactured, supplied, and fitted within just one week, enabling the hydropower station to resume operation and continue producing green electricity.
We also provided the seals on an installation mandrel and other assisting rings to assist with the assembly process.
