L485M输气管道水压试验泄漏原因分析

针对某L485M钢级输气管道在水压试验中发生泄漏的现象，对泄漏部位进行了外观检验、理化性能及腐蚀产物分析。结果显示，该管线泄漏点位于管道6点钟位置，管线内壁腐蚀严重，主要表现为全面腐蚀及较深的腐蚀坑；泄漏的主要原因是由于土壤及水等进入管道，钢管内壁受腐蚀减薄，钢管承载能力下降，当试验压力大于钢管承载能力时，钢管开裂泄漏。对于新建管线，建议及时进行管道内部清理，避免对钢管内壁造成腐蚀，对于不能及时投入使用的新建管线，应在内部清理、干燥后进行封堵，避免泥土及水分等进入管线内部而导致腐蚀。

Cause Analysis of L485M Gas Transmission Pipeline Leakage during the Hydrostatic Test

The causes of leakage in L485M steel gas transmission pipeline during hydrostatic test were investigated by appearance inspection and analysis of physical and chemical properties and corrosion products. The leakage point of the pipeline is located at the 6 o ’clock position of the pipeline. The corrosion of the inner wall of the pipeline is serious, mainly manifested as comprehensive corrosion and deep corrosion pit. The main reason for leakage in hydraulic test of the pipeline is that soil and water enter the pipeline, the inner wall of the steel pipe is corroded and thinned, and the bearing capacity of the steel pipe decreases. When the test pressure is greater than the bearing capacity of the steel pipe, the steel pipe cracks and leaks. For the new pipeline, it is recommended to clean the pipeline in time to avoid corrosion on the inner wall of the steel pipe. For the new pipeline that cannot be put into use in time, it should be cleaned and dried inside and blocked to prevent soil and moisture from entering the pipeline and causing corrosion.