Wheel Refurbishing Workshop: New Technologies and Expanded Performance
Our Wheel Refurbishing Workshop (RR) is dedicated to the repair of pump and turbine wheels abraded by water-borne sediments. The development of new technologies now allows us to optimise repair works on wheels while also considerably improving their final quality.
Wheel refurbishing involves welded material deposition to compensate for worn metal. This is followed by surface grinding to obtain an optimal hydraulic profile.
A major repair of a Pelton turbine can take up to one year of work, involving mainly manual tasks. Compensation of the losses of material due to wear requires the welded deposition of nearly 900 kg of steel over more than 600 hours of work.
To restore the original shape of the turbine buckets, the miller must then dedicate more than 1000 hours of “artistic” work to ensure that, once again, the water hitting the Pelton turbine achieves the best possible performance. In the meantime, the wheel also undergoes stress relief annealing. In our machining centre, it is checked and, if necessary, the coupling plate is adjusted to ensure correct mounting on the turbine shaft.
The development of new technologies now allows us to optimise repair works on wheels while also considerably improving their final quality. 3D scanning and milling of complex geometrical shapes on our CNC machines ensure that an optimal hydraulic profile is obtained.
The improvement of wheel abrasion achieved by laying a tungsten carbide coating together with the increasingly competitive price of new equipment encourage us to seek less expensive repair solutions. Over the years, work in the Wheel Refurbishing Workshop has diversified and, thanks to the skills of our workers, we have been able to expand the range of our services.
- Stainless steel piping projects have been implemented for pumping stations, for example at La Veudale, Nant de Drance or Indivis for the Municipality of Hérémence.
- The repair of the various valve gate bodies and components through the application of stainless steel, steel or cupronickel refill allows the complete refurbishment of hydraulic parts in our Workshops.
- The production of special mechanically welded parts also provides our assembly team with the handling tools necessary for their work.
- In the context of hydroelectric plant operation, our workers are called on to intervene on the various sites for repairs of non-transportable items, such as penstocks, head gates or distributors.