Vianden Hydropower Station: turbine 10 pressure shaft

The challenge

The steel pressure shaft feeding turbine 10, roughly 19,000 m² of vertical, inclined and horizontal penstock, needed lasting corrosion protection in permanent contact with water, with as little plant downtime as possible.

The outcome

After blast cleaning, the shaft was lined with two coats of Numastec AQUATA®, a solvent-free two-component epoxy, to a total dry film thickness of 800 µm. It was applied by heated airless spray, with film thickness checked and the first coat pore-tested before the second.

Specification

• Blast cleaning to Sa 2½
• Two coats of AQUATA®, 800 µm total dry film thickness
• Heated two-component airless spray
• Film thickness control after each coat
• High-voltage pore (holiday) test on the first coat