Research on the reliability methods of corroded pipeline
SHUAI Yi1, SHUAI Jian1, LIU Chaoyang2
1 College of Mechanical and Transportation Engineering, China University of Petroleum-Beijing, Beijing 102249, China 2 Petrochina pipeline R&D center, Langfang 065000, China
There are many reliability evaluation methods for the corroded pipelines. But there is no unified standard and the versatility is poor. In order to solve the problem, this paper studied a prediction formula mentioned in one literature. The error analysis shows that it has higher precision than the models of ASME B31G-2009, DNV RP-F101, PCORRC, CSA Z662-07, RAM PIPE REQUAL and NETTO ET AL. Based on the structural reliability theory, a limit-state function is de?ned. Then the probabilistic damage model is formulated and numerically calculated by using Monte Carlo Simulation (MCS). The failure probability of a corroded pipeline was calculated, and compared with the candidate standards. The results show that the failure probability calculated by this model is similar to that calculated by the allowable stress methods of PCORRC, ASME B31G-2009 and DNV RP-F101. This indicated that the new prediction formula can provide a choice for the reliability analysis of corroded pipelines. Through the parameter sensitivity analysis, it is found that an increase in the variation coefficient of random variables as wall thickness, diameter, internal pressure and radial corrosion rate may lead to an increase or a decrease in the failure probability. It is pointed out that the radial corrosion rate and internal pressure are the two key factors affecting the reliability of corroded pipelines.
Key words：
corroded pipeline in-line inspection failure probability limit state sensitivity
