Repair of small damages in steel pipes with composite patches

The temperature change, internal pressure and corrosion are main reason of cracksin pipes. Removal of damaged pipes with new ones gives rise to major disruptionduring operation. This causes loss of time and cost. This study aims to prevent crackpropagation and to obtain fast repair in damaged area, at the beginning of the dam-age. Repair of small cracks in steel pipes using composite patches has been studiedin this work. The aim of the study is to repair small cracks less than 8 mm length.For this purpose, holes with 8 mm diameters were drilled in 170 mm long pipes andcomposite patches with 2, 2.6 and 3.2 mm thickness and 35, 40 and 45 mm overlaplengths with 60, 90 and 120o overlap angles were attached with an adhesive of0.2 mm thickness. The repaired pipes were subjected to internal pressure until dam-age occurred. A finite element model was developed and the numerical results wereverified based on experiments. The repair of steel pipe with adhesive bonding wassuccessfully achieved under high pressure with composite patches.The results show that the increase in overlap angle results in an increased sur-face area, and consequently an increase in failure load. Furthermore, the failure loadincreased with an increase in patch thickness. Additionally, it is seen that the failureload does not change significantly with increasing patch thickness.