For almost three decades, composite repair technology has provided valuable alternatives to operating companies in maintaining the integrity of their high-pressure gas and liquid pipeline systems. Early adopters of the technology helped to push the usage of these beneficial materials to where they are today. As with all technology, increased usage drives increased scope of usage, and there have been extensive and comprehensive, full-scale testing programs dedicated to pushing the boundaries and opening new defect repair options. These have been funded jointly by industry and manufacturers and have yielded successful results further showcasing the full range of benefits that composite materials can provide. Benefitting from this history and background allows for a better repair option based on experience and lessons learned. Development of new technologies, methods, and materials has been ongoing, and results show improvements may be made by using lessons learned in conjunction with technologies now available.
The contents of this paper focus and provide details on the development of specialized composite technologies for reinforcing anomalies such as corrosion and dents subjected to aggressive operating conditions. Additionally, small-scale, coupon-level testing results are used to characterize the effects of constitutive component changes in order to take the next steps prior to full-scaling, including burst and cyclic pressure testing. Information is included on the initial design process used by engineers to optimize reinforcements using constitutive properties and insights from previous testing and research programs to guide the advancements in understanding of the materials. Detailed test results are included, with information on how both coupon-level and full-scale test results can be used to assist operators in repairing and maintaining their pipeline systems using optimized composite reinforcing technologies.
Previous testing programs on a composite repair material were completed to show the optimization process to produce the best repair system by altering and optimizing the individual components of the system. This was undertaken based on multiple industry testing programs and material knowledge gained over the course of the past 20 years, along with newer technologies and material improvements. Initial coupon-level, development testing was conducted to determine the appropriate design options for review to determine most effective fiber architecture, and upon analysis of the results, a final product specification was chosen for further full-scale testing in addition to full qualification testing from ASME PCC-2 Article 4.1 and ISO 24817 standards.