A leading energy company in the UK recently required refurbishment of two jetty intake screens. The screens had been in service for approximately 12 years and had suffered mechanical damage. The client had also welded on new lifting points which required protection and coating repair. They had previously needed to take out the screens and manually remove the marine growth. This restricted the water flow through the cooling water system, reducing the efficiency of the condenser. As a result, this had the potential to impact the power generated from the station.
Upon arrival to the workshop the screens were flash blasted to reveal the true extent of the damage and in turn the repair required.
Surface preparation then followed on the carbon steel substrate and on the new lifting lug area. Following cleaning to prepare the surface ahead of coating, Corroglass 600 Series was then used. A minimum DFT of 900 microns was achieved, with the appropriate thickness and spark tests completed, following adequate cure.
Biofoul was applied via airless spray, as a topcoat to achieve a minimum DFT of 300 microns. Biofoul was selected as it has excellent long term fouling resistance. It will also resist flow velocities of up to 25m/s. The coating contains metallic copper and no fillers which are classified as toxic, such as TBT and some copper salt materials.
It has been tested and found to be non-toxic in salt and fresh water and is certified as TBT free by Lloyds Register.