Integrity increasing of damaged transporting pipelines using fiber reinforced polymer composite wrap systems

Abstract

The main objective of the ongoing research is data collection for integrity management tasks, helping the transporting pipeline operators in different decision situations. On the one hand, can be used the composite repairing and reinforcing systems for a long-term; or there are only appropriate for a short-term maintenance period. On the other hand, can be identified the reserves of the girth welds after a long-term operation; or the girth welds with different defects should be repaired and/or replaced. The paper introduces a full-scale pipeline investigation program. Fatigue and burst tests were executed on repaired pipeline sections containing artificial surface and through-wall defects, modelling gouges and leakages, respectively. Both separate and interacting flaws were investigated. Different composite reinforcing methods, in other words wrap systems, were applied, investigated and compared. Furthermore, long-term operated and cut gas transporting pipeline sections containing girth welds were investigated, too. The testing results and the damage histories were compared with each other; safety factor was defined and calculated for the assessment of the effectiveness of the reinforcing systems and the reliability of the girth welds.