Analysis on Rupture Failure of Field Coating for Welded Joint in Dongying-Linyi Parallel Oil Pipeline

Taking the pipe rupture accident of inlet pipeline at Qiaozhuang Pumping Station in Dongying-Linyi Parallel Oil Pipeline as an example, an analysis on the characteristics of field coating material for welded joint around rupture area and corrosion factors is carried out from the rupture form of pipe, investigation on the effectiveness of impressed current in cathodic protection system, testing to soil resistivity, depth of pipeline and property of coating materials. It is concluded that insufficient depth of pipe and poor adhesive material resulted in pipe corrosion under the effect of temperature difference, pipe rupture happened when instantaneous surge pressure produced. Relevant protection measures against the issues and recommended requirements are presented.