Puerto Rico, Aguirre's Power Plant

Custom-Made Carbon FRP Pipe Reduces Manhole Repair Time

Aguirre Electrical Plant, Puerto Rico

The Problem:

The cooling system in Puerto Rico’s Aguirre Electrical Power Plant consists of a large network of pressurized pipes with 29 manholes.  The top 4’ of each of these manholes were corroded and required strengthening for both internal pressure and overburden pressure from nearby traffic.  The plant wished to minimize the installation time and improve the quality of the FRP repair.

The Solution:

StifPipe® (patent-pending) was selected for this project. Each section of StifPipe® was custom made to be 4’ long with an outside diameter of 34.5”.  The wall of the StifPipe® consisted of a ¼” thick 3D fabric with two layers of carbon fabric on the inside and two layers of glass fabric saturated with epoxy on the outside.  This resulted in pipe that can withstand over 150 psi internal pressure Each StifPipe® segment weighed only 105 pounds.   In the field the StifPipe® segments were easily inserted in the manhole by hand and the small ¾” annular space was filled with grout.
The overall rigidity of the StifPipe® was designed to resist the external pressure independent of the host pipe.

Tucson, AZ

The Results:

The fabrication of StifPipe® in advance of the shutdown required for installation resulted in significantly shorter downtime and higher quality when compared to wet layup FRP.  Only three hours were required to repair each manhole. 

More information is available at http://pipemedic.com/stifpipe.php or by
calling (520)791-7000.

Notice the minimal annular space
achieved by custom order of StifPipe®