Anticorrosion Performance Detection And Integrity Evaluation Of Municipal Gas Pipeline In A City Of Zhejiang Province

As a carrier for the natural gas transportation, connection between the upstream anddownstream resources with consumers, buried steel pipeline has become one of important cityinfrastructures. The pipeline external anticorrosive coating corrosion will happen for the longrunning under the complex environment, thus it will cause the pipeline corrosion, pipelineperforation, gas leak phenomenon, etc. It will usually bring about grave loss to the life andproperty of people and the construction of national economy. So buried steel gas pipelinecorrosion detection and integrity evaluation play an important role in the safe operation ofpipeline.There are dozens of technology and methods for pipeline corrosion detection at homeand abroad nowadays. They have their own advantages and disadvantages in actual detection.This paper has mainly summarized the methods and principles of different detectiontechnologies. And specify some of these technologies by using the detection results ofhigh-pressure pipeline and courtyard pipeline in a city of Zhejiang province.Buried steel pipeline corrosion detection mainly includes pipeline anticorrosive coatingdetection, soil corrosion detection, stray current detection and cathodic protection systemdetection. And pipeline anticorrosive coating inspection including damaged point andinsulating resistivity detection. Soil corrosion detection results show that the soil has certaincorrosive. Stray current testing results show that testing points in the pipeline have been acertain degree of dc stray current interference. There is one point pipe-to-soil potentialmaximum offset reached162mV, this pipeline should be take electric drainage measures.Anticorrosive coating insulation resistivity inspection results show that the pipelineanticorrosive layer insulation effect is well as a whole. Only in the presence of a nearbydamaged point on the coating of anticorrosion layer insulation effect is poor. Anticorrosioncoating damaged points detection shows that exist3damaged points in the city gas pipeline,courtyard pipelines exists2coating damage points. Cathodic protection potential tests showthat the pipe-to-soil potential of all test points conforms to requirements. We can complete thecomprehensive evaluation on the buried steel pipeline and put forward the effective controland management advices of the pipeline corrosion by the test results of the buried steel pipeline.