Development and application of self-driven inner detector for D 1 422 mm pipelines before commissioning

To solve the problems of insufficient power, high speed impact, high energy consumption, etc. of the detectors applied to large-diameter pipelines before the conventional cup-type pipelines are put into production, the self-driven inner detector suitable for large-diameter pipelines was developed. As the detector is capable of travelling autonomously inside the pipeline, detecting the geometric deformation of the pipeline and shooting the internal video of the pipeline, it can be used for pipeline inspection before commissioning or during the shutdown maintenance period. The overall structure and body design of the detector were introduced, the influence of travelling attitude on driving force was analyzed, the design and function of the detection unit were systematically expounded, and the motion characteristics and detection performance of the detector were verified through field application tests. After being applied to the pipelines under construction in China-Russia Eastern Gas Pipeline Project, the application results show that the endurance mileage of the detector reaches more than 50 km, and the synchronous visual inspection on geometric deformations of the pipeline, internal surface defects of the pipe wall, foreign matters such as water film inside the pipeline is realized, thus demonstrating its excellent usability and advancement in practice.