Security Evaluation To River Tranversing Oil Pipeline

The research to the security evaluation to oil pipeline in service rises from in 1970s overseas. It is firstly applied in security evaluation to the pipelines under pressure in nuclear power station in USA, while in China, it begins with the security evaluation to oil pipeline in middle 1990s in our country. After the local study to the tranversing pipeline in northeast and northwest China, various types of tranversing and invalidation of pipeline taken into sight, it is concluded that there are four tranversing mode and six invalidation mode of tranversing pipeline referring to related information domestic and overseas. By simulating the stress state of the pipeline under flood impact, the relationship of different place of pipe wall in annulus orientation when pipeline is bare and hang in the air and the corresponding stress, and stress curve of pipeline of various bare grade under flood of various velocity are depicted here, which are compared with the result from the computing software Fluent. The affected factors to the whisht intensity of pipeline is analysed in two aspects: defectiveness and non. In the non-defectiveness aspect, the tranversing pipeline is considered as thin-wall container, and the annulus stress emerged from inner pressure as main stress on base of stress influence colligated with temperature and inner pressure, then amends it with the axis orientation stress, with the 4th intensity theory, we can calculate the whisht intensity of river tranversing oil pipeline. In another aspect, the security of pipeline can be judged from the rupture safety factor of pipe material. Based on the whisht intensity analysis to the tranversing pipeline, affected factors to moving intensity is analysed and calculated in two aspects, including the flux load and vibration mainly emerged from landscape orientation flux load. In colligated view of the influence of the whisht and moving intensity, the tranversing pipeline is analysed. Vibration of the tranversing ends is estimated from the tranversing length being exceeded or not and whirl vibration emerging or not. The remaining life of river tranversing oil pipeline is calculated in two aspects: fatigue and erosion. The fatigue remaining life is calculated by extending of fatigue crack theory; on the other aspect, calculation of the erosion remaining life is introduced with the method of finity folded line, instead of curve.