Composite materials continue to gain wider acceptance in the pipeline industry for repairing a range of pipeline anomalies. This is due in part to the contribution of comprehensive research programs including projects such as this.
This is the second project sponsored by PRCI focused on evaluating composite materials to repair damaged pipelines. The first is an ongoing long term study of the performance of composite repair systems for corrosion damage. The purpose of this project is to determine if composite materials can effectively repair dents in high pressure pipelines subjected to cyclic pressure service.
The results of this research, recently published in a report available to industry, indicate that when properly designed and installed, composite repair systems are able to restore integrity to mechanically-damaged pipes to a state that makes them fit for continued use at their normal design conditions. As discussed in the report, when composite materials are used for repairs, whether the repair involves corrosion, dents, or other anomalies, any integrity assessment should include an estimate of the future operating conditions to ensure that the design is adequate for the intended service.
The main deliverables from this study are design guidelines, developed from full-scale experimental data, for repairing pipelines using composite materials. The central feature and benefit will be the design fatigue curves generated from this experimental data. These guidelines will assist pipeline companies in determining the increase in service life of the pipelines repaired using composite materials and the level of performance that can be expected, subject to the internal pressure during installation. This study in particular considered 12.75-inch X 0.188-inch, Grade X42, ERW material; however, the same trends should be expected in larger D/t ratios, other pipe fabrication processes, and different material grades.
PRCI Members can download the final report here. The report is available for purchase here.