Abstract
In 2015, composite repair materials were used for the first time in an extensive pipeline crack repair testing program. Since that time, multiple test programs have continued to show the functionality of using a carbon fiber, epoxy composite repair system to significantly slow or deter crack growth in axially oriented cracks or crack-like features. To further build onto this successful testing, CSNRI, in conjunction with Williams Pipelines and ADV Integrity, has received pipe spools with SCC that were removed from service for testing purposes. These samples are repaired with the Atlas repair system, cycled, and then pressurized to burst while continuous strain gauge measurements are made on the SCC colonies.
This paper will first provide a brief overview on the theory of how composite materials can be used to provide a permanent repair for standard pipeline SCC defects. The test results will then be discussed with a focus on strain-based results compared between three samples: A baseline sample with no repair, a repair performed at no pressure, and a repair performed at a pressure equivalent to 50% SMYS. All test samples have SCC ranging from 40-60% through-wall. The test results clearly show a reduction in peak-to-peak strain when repaired. The sample installed with pressure additionally shows the impact of installing at pressure, namely that the peak-to-peak strain values are similar when compared with the repair installed at 0 pressure.
