A recent statement published by Belzona discussed above ground industrial storage tanks and their contents, which as all in the industry know, represent extremely valuable assets that need to be protected.
It said secondary containment or bunding is “both costly and potentially dangerous” and offered a case study as an example of how it could help companies avoid such a circumstance.
“A storage tank farm based in Italy was used as a collection site for exhausted oil from machinery. After an intervention from the environmental monitoring public authority, pollution problems were detected within the site. Due to the gradual deterioration of the storage tanks from environmental damage and internal corrosion, the tanks and surrounding containment areas didn’t meet environmental standards. Therefore, the site required a complete refurbishment.
Belzona’s Italian Distributor, BS SRL, were able to offer a complete turnkey solution to restore the deteriorating tank farm. Through a constant local presence, BS SRL were able to provide a reliable, long-term and high-quality technical proposal.”
It said the internals of the tank needed a suitable coating that could provide protection against the oils. Due to a mixture of water and hydrocarbons, the bottom of the tank started to corrode where the water sits. This is because, it said, the density of the water is greater than the hydrocarbons and as the steel is unprotected, the tank corroded at the bottom.
The storage tank was drained, and power washed to get rid of any loose contaminates and debris. Once dry, the tank was grit blasted to SA 2.5 before 2 coats of Belzona 5811 were applied to the floor and roughly 1 meter up the internal walls.
For the external surfaces of the storage tank, the surface was once again grit blasted to SA 2.5 before firstly applying 2 coats of Belzona 6111 (Liquid Anode). This zinc-rich epoxy system acts as a long-term steel protection system for surfaces subject to environmental corrosion. Belzona 6111 was then followed by 2 coats of Belzona 5111 (Ceramic Cladding) for its good UV resistance. The system also provides an aesthetically pleasing finish whilst also providing long-term protection to the storage tank.
The base of the storage tanks needed to be repaired and protected due to wear. Over time, moisture accumulated at the chime angle of the tank, leading to corrosion. Tank base corrosion can also be caused by the expansion and contraction of the tank or failure of mastic type sealants.
It said conventional sealing methods, such as mastic tapes, are subject to shrinkage and UV attack and do not allow moisture to escape. A solution therefore needs to be put in place to allow trapped moisture to permeate out, allow flexibility for expansion loading, and offer a long-term, durable solution.
Primarily, the tank base had to be rebuilt to the original surface due to a loss of material over time. Belzona said that if left without treatment, “the structural integrity of the tank base would have been at risk.”
For more information visit www.belzona.com