油气管道漏磁内检测器的变径结构设计

Variable-diameter structure design of MFL inline detector for oil and gas pipelines

为满足管径610~762 mm长输变径油气管道的内检测需求,研制了一款适用于此口径油气管道的漏磁管道内检测器。新设计密封节采用折叠型皮碗,磁路及探头采用浮动式结构,探头双排交错布置,提高了检测器的变形能力,优化了整体机械结构。通过磁化能力测试、直管牵引试验及气密性试验对检测器的性能进行测试,试验结果表明:磁路可满足检测10~20 mm壁厚管道的磁化需求;折叠型皮碗密封性能良好,可为检测器提供所需的驱动力;磁路及探头浮动效果良好,在不同管径中可保持对管壁的贴合,满足检测要求。此检测器结构实现了管道漏磁内检测的变径功能,对促进变径油气管道智能内检测器的国产化有着积极作用。

In order to meet the requirements of long-distance oil and gas pipelines with variable diameters of 610-762 mm for inline detection, a Magnetic Flux Leakage(MFL) inline detector applicable to such oil and gas pipelines was developed.In the new design, a folded cup was used for the sealing section, the floating structure was applied for the magnetic circuit and probes, and probes were arranged in two rows in a staggered way. Thus, the deformability of the detector was improved and the overall mechanical structure was optimized. In addition, the performance of the detector was tested through the magnetization capability test, straight pipe traction test and air tightness test. According to the test results, the magnetic circuit can meet the magnetization requirements of pipeline detection in a wall thickness of 10-20 mm, and the folded cup,with good sealing performance, can provide the detector with the required driving force. Besides, the floating effect of the magnetic circuit and probes is good for pipelines with different diameters, so that the detector could fit well with the pipeline wall to meet the detection requirements. In general, this structure of detector realizes the function of diameter variation during MFL inline detection, and plays a positive role in promoting the localization of intelligent inline detectors for oil and gas pipelines with variable diameters.