Testing of Composite Repairs according to ISO & ASME standard and beyond
Proceedings Publication Date
Maintaining pipelines is a priority for every operator to ensure safety, efficiency and sustainability. Composite wrap repairs are an alternative repair method which is less expensive and less time-consuming, but which enables an extension in lifetime of up to 20 years. It is particularly suitable for live repairs to avoid unplanned shutdowns. Although it has been used in the field for more than two decades and is described in the standards ISO 24817 and ASME PCC-2, the technology is still not always applied, or even considered as a solution in situations where it would be of advantage. Based on its expertise in adhesive technology, Henkel Loctite has developed a composite repair system which meets the standards ISO 24817 and ASME PCC-2. Furthermore, in order to increase the level of confidence, the Composite repair system for pipes underwent several years of certification processes defined and fully audited by independent inspection authorities, namely DNV GL, Lloyd´s Register and TUEV Rheinland. Henkel operates with its standard repair system up to 80°C and with a newly developed high temperature system up to 130°C. Both these systems have been approved and certified according to the standards. In addition to the testing program required by ISO and ASME, a range of further experimental investigations, exceeding the requirements of the repair standards, has been carried out to show the performance and robustness achievable by composite repairs. Important topics covered include tests on cyclic dynamic pressure loads, the fatigue strength of the composite, and permeation resistance vs. gaseous hydrocarbons. Furthermore, a FEM model has been developed that enables the design of repair cases which are not usually described in detail by the repair standards, like the repair of dents. The combination of these methods clarifies further details and improves our understanding of composite repair reliability.