Corrosion in pipeline walls will can lead to severe loss of material to a point which will cause complete loss of pipeline integrity. Contemporary approach of corrosion prevention is to use internal lining system to isolate the corrosive medium from the host pipe's inner surface. The objectives of the current study is to assess the burst pressure of standalone pipelines with internal corrosion defects (Part 1), whereas the sequel paper (Part 2) addresses the potential increase in burst internally corroded pipelines rehabilitated with a novel multi-layer Kevlar-reinforced semi-flexible polymer composite liner.
In this part of the study, the mechanical response of carbon steel API X42, X52 and X70 pipe grades are empirically estimated and implemented in a finite element model. The geometry of internal corrosion defect is defined through its depth, width and length and a parametric study is undertaken to investigate the influence of the corrosion defect parameters to the overall burst pressure of the pipe. Based on the results from the parametric study, the Buckingham p-theorem is used to derive an analytical closed-form expression to predict the burst pressure of internally corroded pipes, which is found to agree markedly well with experimental results. The work in the current study (Part 1) is developed solely for standalone internally corroded pipes and will hence provide a fundamental basis for the sequel study (Part 2), with the objective to develop a similar expression for the burst pressure of pipes rehabilitated with the liner.