Problem

At a chemical plant, the primary storage tank filled with acid wastewater needed an inner protective coating, as the chemicals were deteriorating large sections of the tank. The concrete tank was previously protected by PVC lining which only provided a minimal level of protection, not suitable to meet customer expectations, due to continuous need for repairs, and ongoing maintenance. The customer needed a more robust protection and higher performing coating system that would repair, seal and protect against further and more damaging acid attack.

Solution

Devcon Epoxy Concrete Sealer and Devcon Epoxy Coat 7000 AR for refurbishing, reconstructing and protecting delivered the needed resistance to their acidic chemical attacks.

• The concrete surface was prepared using NACE standards and the Devcon Epoxy Concrete Sealer applied as a self-leveling primer with conventional roller brushes. There was excellent adhesion to the concrete creating both a bonding bridge as well as a secondary barrier against harsh chemicals.
• For their ultimate protection, after curing the Devcon Concrete Sealer to the appropriate recoat time, the Devcon Epoxy Coat 7000 AR was applied with a “back roll” for a smooth and continuous coating. The final coating was carefully applied over joints or seams to prevent leaks and delamination.
• 1 coat of Devcon Epoxy Concrete Sealer (250 microns) and 2 coats of Devcon 7000AR (200 microns each) were used. The tank was back in service within 1 week, significantly faster than the former solution.

Project Outcome

Long-Term Protection & Faster Application

The superior protection from the two seamless Devcon coatings now allow the tank to withstand solutions containing 98% sulfuric acid, 50% phosphoric acid, and 36% hydrochloric acid among others. Compared to the previous PVC lining, the Devcon epoxy protection provided a faster application, a continuous joint free coating with strong adhesion and sealing. The Devcon epoxy solution reduced tank downtime and maintenance efforts. After 2-3 years in operation, there are no signs of damage or other latent problems.