July 1, 2010

New Coating System Extends Life of Cooling Tower

By Sherwin-Williams, Cannon Sline Industrial, and OTB Technologies

American Electric Power’s (AEP’s) Cardinal Power Plant Unit 3 cooling tower in Brilliant, Ohio, was coated and lined in the spring of 2008 by a team of coatings professionals that included the plant’s project and coatings engineering staff, Sherwin-Williams (coatings supplier), Cannon Sline Industrial (contractor), and OTB Technologies (third-party inspector). The team completed the project in just 11 weeks through damp springtime conditions in the Ohio River Valley (Figure 1).

1. Cooling tower refurbishment. The AEP Cardinal Power Plant Unit 3’s 457-foot-tall concrete cooling tower was refurbished in the spring of 2008. The 11-week project began with the tower’s first pressure washing in 30 years, was followed by surface repairs, and was topped off with a fresh coat of primer and paint. Courtesy: Sherwin-Williams Co.

The team formulated a fast-track coatings system and application process to extend the service life of the tower while reducing cost-prohibitive downtime. The schedule also included time for pressure washing the 457-foot-tall tower’s concrete interior of more than 30 years’ worth of dirt and biological growth.

Key among the contractor’s challenges, according to Cannon Sline President Mark Chuplis, was the job’s overall rigging and staging. “Envision an hourglass,” he said. “You’re pushed into the side at the top and drift away from the substrate at the bottom. You can’t make a mistake at over 400 feet in the air; you don’t live to repeat it. Everything we did had a professional engineer’s stamp on it. And it’s not a job for the faint of heart. Our union-trained painters really helped make this job a reality.”

Another concern was the ability to spray coating material from the base of the tower to a vertical length of 500 feet. “No one had ever pushed this type of material that distance straight up in the air before,” Chuplis said. “We actually tested coatings through 500 feet of spray hose in the specification process to make sure it would work properly.”