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.

Our approach

We start by 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. We rebuild the pitted and thinned areas cold with Belzona 1000 Series composites, bringing the steel back to profile with no hot work on a tank that holds crude. Then we apply a Belzona 5000 Series barrier coating over the roof and shell to separate the steel from the weather and stop further atmospheric loss. We work the surfaces in stages so water cannot get back under the coating before it cures.

1. Assess and mapWe inspect the roof and shell to locate pitting and metal loss and confirm the areas that need rebuilding before coating.
2. Blast to clean steelWe abrasive blast 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 areasWe rebuild pitted and thinned steel cold with 1000 Series composites, with no hot work on a tank in crude service.
4. Apply barrier coatingWe apply a 5000 Series barrier coating over the roof and shell as one continuous film that separates the steel from the weather.
5. Cure and return to serviceWe confirm the coating is cured and continuous, then hand the tank back to the owner ready for service.