High Temperature Performance of Bonded Composite Repairs for Pressure Vessels

Bonded composite repairs are commonly used as both a temporary and permanent repair method to restore damaged pressure vessels and pipelines. This repair approach is used in a wide variety of industries, including the oil and gas industry. Design and qualification of repair method have been standardized by the ASME post-construction codes. Significant literature has been generated to understand the behavior of these repairs under a variety of loading conditions, both static and dynamic. However, this repair type has typically only been investigated at or near room temperature. As the application possibilities for these repairs expand, higher service temperatures have become a focus for both repair manufacturers and operators. High temperatures (> 250°F) have a number of impacts on polymer composites, including reducing the elastic modulus of the repair material, which tends to reduce the repair strength. Therefore, it is critical to understand the effect of temperature on both the individual composite components, as well as the overall composite repair system. The research presented here studies the influence of temperature on bonded composite repair systems at service pressure (3000 psi) and high temperature conditions. This high temperature is generated using a heating element inside the repaired vessel while contained inside an insulated oven. Strain measurements of the repair are also investigated during a quasi-static testing.