Safe, clean drinking water is essential for the health of individuals and communities. The American Rescue Plan is investing $55 billion in clean drinking water and water infrastructure across America. According to the EPA, there are over 148,000 public water systems in the United States that provide drinking water to 90 percent of Americans. Drinking water distribution systems link treatment plants or water sources to customers through a network of pipes, water tanks and storage facilities, valves, and pumps. Asset preservation is a top priority for municipalities and other water system owners, and now is the perfect time to assess whether corrosion in water tanks is impacting water quality.
What Causes Corrosion and Pitting in Water Tanks?
Water tanks are usually made of steel or steel and reinforced concrete (composite tanks). Corrosion in water tanks is the result of the natural reaction of steel with oxygen and water, and can be accelerated by factors such as water temperatures, acidity (low pH) and high mineral concentrations. Corrosion can impact water quality, cause leaks and premature failures, damage structural integrity, and interrupt service during failures and repairs.
Pitting is a localized form of corrosion and metal deterioration, with damage ranging from deep crevices to shallow dents. A common cause of pitting is chloride ions founds in salts and bleach that damage steel. Excessive pitting in water tanks can increase maintenance costs and lead to service interruptions.
Applying Industrial Coatings
Water storage tanks are subject to corrosion on both external and internal surfaces. To protect against corrosion, industrial coatings or volatile corrosion inhibitors (VCIs) can be applied. The type of protective coating selected is based on whether the surface holds potable water and environmental factors, including salt air, temperature, acidic and alkaline environments, chemicals, and toxins.
Surface preparation starts with solvent cleaning. A primer is then used on all bare surfaces, followed by application of an epoxy industrial coating. Designs on the exterior of water tanks range from the name of the town to colorful paintings that set the tone for the community.
Epoxy coatings are formulated for interior water tanks that meet American Water Works Association (AWWA) and National Science Foundation (NSF) requirements for potable water. These coatings form a physical barrier between the cathode (water) and the anode (steel wall), which prevents electrons from moving out of the steel wall.
Hiring Qualified Contractors
Because water tanks are often located high above the ground, certified contractors with safety training are necessary. Certified Coating Application Specialists have the training and experience to safely and effectively do the job. FSN can furnish QP1 and QP2 certified industrial coating contractors, employing CAS certified workers that know how to prevent corrosion in water tanks.
Call us for all of your industrial coatings needs. Contact us today at (410) 564-5876 or [email protected] to discuss your projects.