Studies Of Magnetic Flux Leakage Testing Technology Of Corrosion For In-servise Industrial Pipeline

Industrial piping is widely used in industrial and mining industry, institutions, changes inits production of complex production environment, working conditions are more stringent andits a kind of pressure pipes which is distinguish from long-distance pipeline and utilitypipes.With the increasing number of China’s petrochemical enterprises, industrial pipelinesincreasingly widespread use, Its range of applications including the fields of petrochemical,natural gas, municipal, metallurgy, nonferrous metals, power, machinery, aerospace, lightindustry etc, the distribution range also includes various areas of the city and county.Industrialpiping and ordinary long-distance pipeline and utility pipes comparison, it’s kind of upprocess, manufacturing production environment status change is extremely complex,conveyed many media types and working conditions are more stringent.So the problems ofindustrial pipelines’ management and safe operation is particularly important.Magnetic fluxleakage detection technology is a method used in industrial and pipeline inspection.This paperintroduces the principle of industrial pipeline magnetic flux leakage external detection, andthe status of the theory,standards, instrument development at home and abroad about theindustrial pipeline magnetic flux leakage testing,to study the factors that affect the magneticflux leakage testing,and the correspondence between MFL signal and pipeline defects.Thistopic source for national nonprofit industry research and special project funding “Magneticflux leakage testing of key technologies and the equipment and standards development”,themain work and achievements have completed are the following:1.The development of pipeline external magnetic flux leakage detection equipmentResearch and development and manufacturing equipment For industrial pipe on lineexternal magnetic flux leakage detection,including the instruments’ reconfigurable mechanicalstructure reconfigurable unit, a drive unit, signal processing and control softwareprogramming.And scanning for the detection of different types of test pieces, and with thedevelopment of mature foreign technology and testing equipment for testing the effect ofcomparison.2.The experimental design and productionFor on-line detection with different characteristics and produce different types of defects,to study the magnetic flux leakage detection signal characteristics, research adapt fast online calibration method to detect and adapt to the precise calibration method using magnetic fluxleakage testing of pressure equipment.3.Research pipeline magnetic flux leakage testing instrument calibration methods athome and abroadComparative advantages and disadvantages of magnetic flux leakage detector Pipescanmagnetic flux leakage detector and domestic research and development, by detectingspecimen of standard pipe and actual testing on-site,detailed comparison in terms ofinstrument calibration and calibration methods, detection methods.4.Factors affecting the magnetic flux leakage testingUsing the method of control variables, the factors that may affect the test results: pipediameter and wall thickness, shape, and position of the defect factors studied.5.Correspondence between the defect signal and flawed researchComparative characteristics of preformed defect signal of various shapes in the pipelinethrough different diameter and wall thickness of the pipe scanning and detection.Using finiteelement analysis software to detect magnetic flux leakage signals may be generated by a widerange of comparison and analysis, and various factors (such as diameter, wall thickness, etc.)of magnetic flux leakage testing results were compared and analyzed in detail, and then theresults of these two tests conducted comprehensive comparison verify the reliability of thetest.6.Study of site testing and test resultsUsing domestic and foreign MFL pipeline inspection system for all types of site (eg,process piping, fire protection piping) by actual scanning operation,and focus on thedefective pipe section to multi-directional scanning and ultrasound reinspection, analysisscanning results validate the instrument detection performance and the reliability of the testresults.