Title: Fiber-Reinforced Polymer Pipe Lining

Author(s): M. Ehsani and C. Pena

Publication: Concrete International

Volume: 31

Issue: 12

Appears on pages(s): 50-53

Keywords: cast-in-place, grinding, penstock, pressure test

DOI:

Date: 12/1/2009

Abstract:
The low-pressure penstock at the El Encanto Hydroelectric Power Plant, located 75 miles (120 km) northwest of San José, Costa Rica was repaired using a fiber-reinforced polymer lining. The project required the installation of about 150,000 ft2 (14,000 m2) of FRP lining in a single phase. Prior to application of the fabric, an epoxy paste was applied to the top half of the penstock and a seal coat of epoxy resin was applied to the bottom half of the penstock. After they were saturated with resin, 50 in. (1270 mm) wide bands of fabric were rolled onto the prepared surface. The edges of the fabric bands were lapped in the circumferential and longitudinal directions to achieve full continuity of the FRP, and the edges of the laps were feathered with epoxy paste or resin. The final step involved installation of an epoxy top coat as a cover for all the installed FRP. The project successfully passed a pressure test and was entered into service.