Crude Storage Tank Roof Corrosion Coating

The challenge

A crude storage tank roof and shell lose wall to atmospheric corrosion. Rain, dew, and standing water sit on the roof plates and run down the shell, and the steel rusts and thins from the outside in. As the metal is lost, pitting opens up and the protective surface breaks down, so the corrosion runs faster the longer it is left. Eventually the thinning threatens the integrity of the roof and the upper shell, and the owner faces plate replacement and a tank pulled from service.

The Belzona approach

Work starts with blasting the roof and shell back to clean, profiled steel so the corrosion product is gone and the repair has a sound surface to bond to. Belzona 1000 Series composites rebuild the pitted and thinned areas cold, bringing the steel back to profile with no hot work on a tank that holds crude. Then a Belzona 5000 Series barrier coating goes over the roof and shell to separate the steel from the weather and stop further atmospheric loss. The surfaces are worked in stages so water cannot get back under the coating before it cures.

1. Assess and mapThe roof and shell are inspected to locate pitting and metal loss and confirm the areas that need rebuilding before coating.
2. Blast to clean steelAbrasive blasting takes the roof and shell to a clean, profiled surface so the corrosion product is removed and the repair bonds to bare steel.
3. Rebuild thinned areasPitted and thinned steel is rebuilt cold with 1000 Series composites, with no hot work on a tank in crude service.
4. Apply barrier coatingA 5000 Series barrier coating goes over the roof and shell as one continuous film that separates the steel from the weather.
5. Cure and return to serviceThe coating is confirmed cured and continuous, then the tank goes back to the owner ready for service.