Primary Settlement Tank

Requirement

Client: Welsh Water Authority.
To overcome the corrosive effects of moisture, chemical contamination and raw sewage, the client had specified a full range of Corroless systems at its Pont Eyre Water Treatment Works. Concrete primary settlement tanks, based upon a radial design, were suffering from severe corrosion, abrasion and delamination. The sludge sticking to the sides of the tanks was slowing down the operation of the scraper blades and using additional power. The client required the concrete to be protected and a hard, smooth abrasion resistant surface created, to prevent sludge build-up on the tank surface and scraper blades.

Preparation

The tanks were high-pressure water jetted to remove laitance and loose material. The damaged surface and blowholes were repaired where necessary prior the application of two coats of Corroless EPF. The scraper bridge was prepared using hand tools.

Coatings

The bottom of the scraper bridge was treated with 2 coats of Corroless EPF. The top of the scraper bridge was treated with a coat of Corroless EPF and two coats of Corroless RF65.

Comments: 
The required protection was achieved with a working life of up to 10 years. A reduction in energy costs to run the plant was also achieved.