Root cause analysis (RCA) of fractured ASTM A53 carbon steel pipe at oil & gas company

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• 作者：M.A. Khattak^a ; ^{mrkohatian@gmail.com} ; N. Zareen^b ; Anique Mukhtar^c ; S. Kazi^d ; Amena Jalil^e ; Zaheer Ahmed^e ; Miraj Muhammad Jan^e ; ^f
• 关键词：RCA (root cause analysis) ; Pipeline ; Excessive grinding ; Raw gas pipe ; NDT (non-destructive techniques)
• 刊名：Case Studies in Engineering Failure Analysis
• 出版年：2016
• 出版时间：October 2016
• 年：2016
• 卷：7
• 期：Complete
• 页码：1-8
• 全文大小：2761 K
• 卷排序：7

文摘

Incident involving failures of 2-in. schedule 80 carbon steel (CS) pipe, connected to pressure safety valve (PSV) and carrying raw gas has caused serious supply disruption. Root cause analysis (RCA) was performed to identify the most probable cause of the pipe failure. In reference to the existing evidence deduced from the tests and substantial existing data the study revealed that the root cause of the pipe failures is attributed to the initial leak of the raw gas pipe. From the basic pipe material properties and behaviour, it is suspected that the failure was initiated by a crack, most probably longitudinal in nature. The crack or horizontal slit allowed high pressure gas to jet through, with the jet momentum getting stronger as the effective diameter of the slit increased. Over time the crack enlarges and breaks off into large chunk, resulting in the gaping hole as evident in the photo record. In view of crack initiation and propagation, it is concluded that the root cause for the failure of the pipe section is due to excessive thinning as a result of thickness reduction by intentional grinding. Further damage to the surface of already excessively reduced thickness occurred due to nominal pipe vibration during service.