The Grande Dixence pumped-storage power plant encompasses 20% of the storage capacity in Switzerland. For the renovation of the pressure pipework, pipe segments with a diameter of three meters were manufactured in situ and let into the existing armouring. The whole was welded together over a length of around four kilometres. To protect against corrosion inside the pipeline Zinc Clad® R was applied as a base coat and Dura-Plate® SW 500 (new product: Dura-Plate® SW-501) as a topcoat over the entire surface of 40,000 m². Controlled heating of the coating material optimised the quality and performance of the corrosion protection.