The Low Head Piping in a power plant consisted of 550 feet of 30 inch and 42 inch pipe. The system supplies brackish cooling water from the Chesapeake Bay to vital components within the power plant. The system is comprised of carbon steel pipe lined with plastisol (plasticized PVC) intended to prevent internal corrosion. Over time, the liner became disbonded from the substrate causing accelerated internal corrosion and subsequently resulted in numerous through wall leaks . Both the inlet and discharge pipes were affected. These leaks and significant areas of corrosion resulted in the poor system reliability and negatively impacted plant performance.
The plant needed to permanently restore pressure boundary and structural integrity within a normal 22 day maintenance outage. Direct replacement of the piping was not a practical option due to time and budget constraints.
The customer selected the C-Wrap carbon fiber and epoxy repair system for its structural capabilities, coupled with economic pricing and favorable schedule. The project required the removal of marine growth and the remaining plastisol lining. Selected pipe spools were removed and other openings were provided to allow access into the piping. The substrate was prepared by grit blasting and the entire piping system was repaired by applying an epoxy primer, a layer of carbon fiber and a top coat. The system was returned to service within the 22 day outage period on budget.