Internal Installation Pressure Effects on Composite Repairs

摘要

Most composite repair installations take place with some amount of pressure in the pipe. The traditional design standards, ASME PCC-2 Article 4.1 and ISO 24817, each provide a design equation that includes consideration of installation pressure but the equations up to this point have been theoretical only and never tested. It is important to note that in the equations, an increasing installation pressure acts to reduce the required composite repair thickness. This experimental test program studied the effects of internal pipe pressure during installation on composite reinforcement systems to verify if the performance of the repair was maintained when applied to simulated corrosion defects. The full-scale testing analyzed the effects on the burst pressure and the cyclic pressure fatigue life of a pipe with a simulated 50% wall loss corrosion defect. The installation pressures considered were varied from 0 up to 50% yield pressure. The installation pressure had no noticeable effects on the burst pressure or the cyclic pressure fatigue life of the pipe; however, the defect region always remained in elastic region during installation. These results indicate that future design work should conservatively assume the installation pressure is 0.