Abstract:The defect monitoring, leak identification and location of buried thermal pipeline are studied in this article. According to the similarity principle, the leakage test platform is established. The infrared thermal imager equipment is used to obversethe surface above the buried pipelineunder three differentworkingconditions. The variation characteristics oftemperaturedistributionof infrared thermal image, maximum differenceradiation temperatureand differenceofthesurfaceabovetheheatedpipeline areanalyzed.Results showthatthe infrared thermal image appears high temperature area, temperature gradient area and natural temperature region around the leakage when the pipeline leaks. The maximum temperature point in the high temperature zone usually corresponds to the location of the leakage point. The temperature gradient area represents the scope of the spill. In addition, the maximum radiation temperature raises fast when the pipeline leaks. The rate is 2 times and 4 times of damaged insulation layer and nondamaged pipeline, respectively. The temperature distribution histogram is changed from normal distribution to positive skew distribution. According to the pixels of the thermal image, the proposed method can calculate the actual area of the affected area of buried pipeline leakage. According to the coordinates of the maximum temperature point, the location of the leakage point can realize pipeline leakage impact assessment and accurate leak location.