Corrosion prevention: Glass/vinyl ester liner protects power plant pit

When PT Paiton Energy in Paiton, East Java, Indonesia, wanted to expand its existing 1,230-MW coal-fired power plant, it needed a new concrete aeration pit to hold seawater that is circulated through the plant’s cooling system. The water also is used to scrub sulfates from stack emissions. Temperatures as high as 122°F/50°C increase the aggressive nature of the acidic liquid environment. Working with general contractor TOA Corp. (Tokyo, Japan) on the expansion project, PT Paiton asked Nuplex Composites, part of Nuplex Industries Ltd. (Auckland, New Zealand), to engineer a solution for a long-lasting and robust aeration pit.

Jason Triggs, technical sales consultant for Nuplex Composites, reports that trademarked Vipel F010 vinyl ester from AOC Resins (Collierville, Tenn.) was selected to seal and protect the poured concrete walls of the pit. Nuplex Composites manufactures and supplies the Vipel resin via a technology licensing agreement with AOC.

“We worked closely with the civil contractors to demonstrate that the AOC technology would meet the demanding criteria for the application,” says Triggs. “Vipel F010 resin is based on a versatile bisphenol-A epoxy chemistry that allows for a range of formulations. Nuplex Composites was able to tailor the resin to balance process, cost and performance requirements.”

Technicians with composites contractor PT Samudera Indoraya Perkasa (Surabaya, Indonesia) first prepared the concrete surface then manually applied a laminate of Vipel F010 resin-impregnated fiberglass chopped strand mat supplied by Nuplex Composites. In the final step, a topcoat of Vipel F010 resin with synthetic surfacing veil established a resin-intensive layer with superior corrosion resistance to protect the poured concrete that makes up the two aeration pit sections, beams and floor. The entire 40,709 ft² (3,782m²) surface received the corrosion-resistant protection.

Triggs says AOC’s technical service team helped Nuplex Composites support the project from quotation to application. The resin was promoted to process well at the plant’s high ambient temperature and humidity, yet have a long pot life during installation. The formulation’s thixotropy permitted vertical application to 16.4-ft/5m high walls without runs or sag. When complete, the power plant expansion will add 815 MW of capacity to the facility.