含腐蚀缺陷海底管道安全评价方法比较

Safety Evaluation Methods Comparison of Submarine Pipelines with Corrosion Defects

海底管道在服役运行过程中,由于输送介质中含有的腐蚀性物质以及周围海水、海泥等环境介质的作用,很可能会发生管内和管外腐蚀,海管壁厚会均匀减薄或形成腐蚀坑、洞等局部腐蚀缺陷。海管强度会因腐蚀缺陷而降低,操作不当时还会引发海管破损和泄漏。安全评价又称适用性评价,是对含缺陷结构是否适合于继续服役使用而进行的定量工程评价。研究比较了海底管道腐蚀缺陷安全评价常用标准和方法的特点、异同及适用条件,并以某海底管道内表面局部腐蚀缺陷为案例,给出了依据ASME B31G-2012《Manual for Determining the Remaining Strength of Corroded Pipelines》和API 579-2016《Fitness-for-Service》进行腐蚀缺陷安全评价的详细步骤和方法。

During the service of the submarine pipeline, it is likely to cause corrosion inside and outside the pipe due to the corrosive substances contained in the conveying medium and the environmental media such as seawater and sea mud, the wall thickness of the sea pipe will be evenly thinned or local corrosion defects such as corrosion pits and holes will be formed. The strength of the sea pipe will be reduced due to corrosion defects, and the sea pipe will be damaged and leaked due to improper operation. Safety evaluation, also known as fitness for service, is a quantitative engineering evaluation method that used to judge whether a defective structure is suitable for continued service. The characteristics, similarities, differences and applied conditions of the commonly used safety evaluation standards for submarine pipelines with corrosion defects were studied. A submarine pipeline with inner corrosion defect was taken as an example to conduct safety evaluation based on ASME B31 G-2012 Manual for Determining the Remaining Strength of Corroded Pipelines and API 579-2016 Fitness-for-Service standards.