24-inch Penstock at Muddy Run Hydroelectric Station renewed using Carbon Fiber System

The Muddy Run hydroelectric station in Drumore, PA has provided power to the regional transmission system since 1966. Generating 1,070 megawatts of clean electricity, this eight-unit hydro plant is imperative in providing power to its surrounding areas.

Eight 24-inch carbon steel penstock drain lines were identified with sections that had internal deterioration due to corrosion. This was in large part due to the lack of an internal coating. Because the drain lines are surrounded by concrete, external repair or replacement was not possible. As an alternative, STRUCTURAL TECHNOLOGIES recommended internal rehabilitation using the V-Wrap™ Carbon Fiber System to the corroded segments, each approximately 16 linear feet in length. Repairs needed to take place during a Spring or Fall outage, typically lasting 10 days.

With STRUCTURAL’s pipe expertise, and STRUCTURAL TECHNOLOGIES’ state-of-the-art CFRP system, the team was chosen for the repair.

An Investigate-Design-Build (IDB) approach was used. This was a unique project as this was the smallest diameter pipe to undergo an internal rehabilitation using the V-Wrap™ Carbon Fiber System. In addition, there were accessibility constraints. The penstock was in the basement of the hydroelectric facility, 65-feet below sea level. Ground level elevation was 22 feet. An elevator was used to access the repair location.

The project was an overall success; completed safely, with no OSHA recordables, within the allotted schedule and budget. This led to STRUCTURAL securing additional work at Muddy Run, which included repairs of the five remaining 24-inch carbon steel drain lines, and another similar project at a sister station.