Ferpècle: successful anticorrosion treatment
The inner coating of the disposal well at Ferpècle had to be entirely replaced. The abrasion caused by the heavy presence of sediments in the water had affected the installation’s anticorrosion protection.
Water from the Ferpècle valley is pumped up to the eponymous plant. It is fed through the supply tunnels of the Grande Dixence complex into the lake at Dix. The Ferpècle disposal well is at the heart of this structure and plays a key role. It has to be able to resist the pressure of 212 metres of water.
Water causes abrasion
Because of its high sediment content the pumped water causes abrasion to the inner coating, meaning the anticorrosion protection had to be replaced over an area in excess of 2,600m2. The work took five months in the middle of winter at the bottom of Val d’Hérens. HYDRO carried out the quality control for the application of the new coating during the various stages of this major project. Once the steel had been prepared, checks were performed on the roughness and the degree of care applied. This ensured the new protection was firmly in place.
Detailed inspection
Other checks were carried out after the coating had been installed. The new surface was inspected to ensure there was no porosity or defects, and that thickness was sufficient over the entire well. The quality controls applied by HYDRO followed rigorous standards, specifically ISO 12944. Each stage underwent minute checks, from preparation to the final inspection.
The flexibility of the HYDRO teams meant it was possible to complete the project without any down time. They adapted to the pace of the company involved in replacing the anticorrosion protection. Quality controls significantly reduce the risk of defects appearing due to the coating being poorly applied.
The roughness checks were carried out using grit.
The reference surface ensures that the coating applied is of high quality.
The final result was impeccable, with perfect anticorrosion protection.
