An experimental investigation of the effect of defect shape and orientation on the burst pressure of pressurised pipes

Al-Owaisi, Sultan; Becker, Adib A.; Sun, Wei; Al-Shabibi, Abdullah; Al-Moharbi, Majid; Pervez, Tasneem; Al-Salmi, Hussain

Abstract

The burst pressure of commonly used ductile steel pipes in oil and gas industries, i.e. X52 and X60, is measured under internal pressure loading. The pipes were machined with circular and boxed defects at different orientations to simulate actual metal loss defects. Defect shapes and orientations were investigated in detail to study how they affect the failure behaviour of interacting defects. The experimental burst pressure results were compared with those obtained using existing analytical methods from Design Codes. Comparison of the results showed conservatism in the existing analytical methods which may potentially lead to unnecessary plant shutdowns and pipe repairs. The outcome of the experimental tests revealed that the shapes of the defects have very small influence on the defect interaction behaviour. The burst tests interestingly showed that the defect orientation has an important effect on defect interaction. Defects oriented in the hoop and diagonal directions showed no defect interaction even when spaced by a distance of one wall thickness, while defects oriented in the longitudinal directions showed that defects interact even when the spacing is up to six wall thickness but the interaction fades away for defects spaced at longer distances.

Citation

Al-Owaisi, S., Becker, A. A., Sun, W., Al-Shabibi, A., Al-Moharbi, M., Pervez, T., & Al-Salmi, H. (2018). An experimental investigation of the effect of defect shape and orientation on the burst pressure of pressurised pipes. Engineering Failure Analysis, 93, 200-213. https://doi.org/10.1016/j.engfailanal.2018.06.011

• Journal Article Type: Article
• Acceptance Date: Jun 15, 2018
• Online Publication Date: Jun 30, 2018
• Publication Date: Nov 30, 2018
• Deposit Date: Jul 4, 2018
• Publicly Available Date: Jul 1, 2019
• Journal: Engineering Failure Analysis
• Print ISSN: 1350-6307
• Electronic ISSN: 1350-6307
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 93
• Pages: 200-213
• DOI: https://doi.org/10.1016/j.engfailanal.2018.06.011
• Keywords: Defect assessment; Pipe damage; Burst pressure; Ductile carbon steel pipe; Finite element analysis
• Public URL: https://nottingham-repository.worktribe.com/output/943758
• Publisher URL: https://www.sciencedirect.com/science/article/pii/S1350630718300645
• Contract Date: Jul 4, 2018