Francis Turbine Cover Repair: A Case Study

6th December 2024

The cover plate of a turbine at a European hydroelectric power station required a Francis turbine cover repair due to extensive erosion along its internal edge from continuous high speed water flow. This wear compromised turbine efficiency and increased the risk of unplanned maintenance, threatening the overall performance of the equipment. A durable repair solution was essential to restore the component’s integrity and ensure uninterrupted power generation while minimising future maintenance downtime.

Resimac’s Francis Turbine Cover Repair Solution

Abrasive blast cleaned the surface to SA2.5, achieving a consistent 75-micron profile.
Rebuilt eroded edges with 204 Heavy Duty Ceramic Paste for a stable foundation.
Resurfaced with two coats of 202 Ceramic Repair Fluid for smooth, protective coverage.

Application Details

The damaged turbine cover plate underwent abrasive blasting to ISO 8501-4 SA2.5 standards, achieving a 75-micron angular profile to ensure optimal adhesion of the repair materials. This thorough surface preparation removed all traces of erosion and contaminants, providing a clean substrate for the rebuilding process. The severely eroded edges were carefully reconstructed using Resimac 204 Heavy Duty Ceramic Paste, restoring the original shape and structural integrity of the cover plate.

Once the foundation was re-established, two coats of Resimac 202 Ceramic Repair Fluid were applied over the repaired areas. Each coat was applied to a precise thickness to create a smooth, low friction surface capable of withstanding high speed water flow.

Products Used

Results and Benefits

The protective coating system restored the Francis turbine cover’s structural integrity and ensured it could withstand the high pressure environment of hydroelectric operations. The repair not only prevented further material loss from erosion but also improved resistance to cavitation, a common issue in high speed water applications. By enhancing the cover’s durability, the solution supported consistent power output and reduced the risk of emergency shutdowns. Furthermore, the application process ensured precise adhesion and uniform coverage, reinforcing the component’s long term reliability.