Industrial tank liners are largely designed to protect water tanks, troughs, clarifiers and filter beds from corrosion against chemicals such as ammonium, sulfuric acid, and other contaminants. The coating is sprayed inside and outside a tank, and they cure fast at low temperatures to provide corrosion resistance and toughness to the substrates material; the material could be concrete, glass, plastic or steel. Water tanks specifically used to store water for human consumption require protective coatings and linings, according to NFS standards on drinking water systems.
When it comes to corrosion resistant tank lining solutions, there are several options to consider including coal tar epoxies, polyurea and polyurethane protective coatings. These have been approved and designed for water systems and wastewater plants.
Types of Tank Liners for Water Systems
The type of tank liner you’ll choose depends on the specific application. So how do you know which is the right option for your project?
1. Two-Component Epoxies
Two-component epoxies are formulated tank coatings consisting of resin and hardeners, ideally suited for both steel and concrete water tanks. Though mix ratio will differ, the two components, resin and hardener, will essentially feature high solids content that cures fast and has superior adhesion qualities to withstand chemical attack and corrosion.
The curing process can be accelerated by applying heat since the reaction is exothermic, however, a thin film coating will take considerably longer to cure than a large mass coating. When applying two-component epoxies it’s important to prepare the substrate material surface, to remove any dirt and contaminants which can greatly affect the quality of the coating.
2. Coal Tar Epoxies Tank Liners
Coal tar epoxies are black polymer coatings featuring various epoxy resins and refined coal that offer protection against both mild and extremely corrosive chemicals. They form high solids coatings which highly adheres to concrete to form strong and durable liners that protect against moisture penetration and chemical abrasion. Coal tar epoxies are also easy to apply with brush, spray, or roller and cure well under room temperature.
Properties and Benefits of Corrosion Resistant Tank Lining Coal Tar Epoxies
- Easy to apply with a brush, spray or roller.
- Highly adheres to oily surfaces
- Offer excellent moisture protection for coatings
- Superior thermal shock and corrosion resistance
- Protect tanks against soil stress
- Ensure good gloss and matte finish
3. Polyurea and Polyurethane Coatings
Polyurea and polyurethane are excellent corrosion resistant tank lining systems. They cure fast at any temperature though the application process is different from coal tar and two-components as it requires specialized equipment. These coatings are environmentally friendly and form a strong and durable bond when applied on bare concrete or steel tank. Polyurea and polyurethane coatings offer more advantages than paint and other conventional coatings. Examples include:
- Easy to apply with brush, spray and roller
- Offer maximum substrate adhesion
- Approved for potable water application
- No primer needed when applied to steel tank
- Consist of high solids
- Offer corrosion and UV resistance
Choosing the right coating system for your water storage tanks is essential in preventing leaks and contaminants to ensure quality and safe water your consumption.