Integrity assessment of the pipelines containing an isolated corrosion pit

摘要

Corrosion pits often appear in steel pipelines under saline or marine immersion conditions and lead to potential risk. In this paper, a double circular arc (DCA) model is firstly established to simulate the pipelines containing an isolated corrosion pit. Then, a burst pressure predictive equation of the pipelines with an isolated pit is provided. Next, the finite element method (FEM) is adopted to verify the accuracy of predictive equation. In the end, comparisons and discussions between the predictive equation and FEM are conducted. The results indicated that undetectable corrosion pits can largely decrease the ultimate carrying capability of pipelines. Furthermore, the DCA model is feasible to simulate the burst behavior of pipelines with an isolated corrosion pit. In addition, compared to FEM, the errors of burst pressure equation are less than 10% for the pipes with an isolated corrosion pit. Finally, accurately predicting the burst pressure and timely repair or replacement of the pipelines with pits can avoid drastic consequences. We provide a novel idea to predict the burst pressure of pipelines with group pits. It is rewarding to study the burst behavior of pitting pipelines and assess the integrity of pipelines.