It is reported from the Xionggu Technical Service Department that the installation and welding task of the Langfang Off-load Branch Pipeline of the Mengxi Project, assisted by the Xionggu automatic welding equipment, was successfully completed. The pipe jacking project crossing the South to North Water Diversion Project+Longjiang Canal is a bottleneck project that restricts the progress of the entire line. The starting shaft is located in Beizhuangtou Village, Bazhou City, Hebei Province, with an inner diameter of 10 meters and a depth of 28.78 meters. The crossing grade of this project is large. The inner diameter of the pipe jacking tunnel is 1.6 meters, and the horizontal length is 258 meters. It mainly includes five main tasks: water stop curtain, open caisson, geological improvement of the horizontal tunnel, mud water balance pipe jacking, and pipeline installation.

The project is contracted by under Huayou Construction Company. Due to the impact of the shaft size, the Mengxi Project Department strictly schedules the construction period in accordance with the node goals, accurately refines the production tasks, clarifies the construction plan to each specific day, firmly determines the construction period, pays close attention to safety and quality control, optimizes resource allocation, increases resource investment, and fully promotes the overall construction progress. The project manager leads the management personnel of the project department to stayed in the construction site, pay close attention to each process, and solve the problems found on the site to ensure the smooth progress of the construction. The welding complex shall operate in 24-hour shifts, strengthen on-site management, and coordinate with the testing company to arrange special personnel to be responsible for weld inspection.

Due to the fact that the shaft is about 25 meters deep and the length of welding cables and control lines is not enough, the automatic welding equipment for the Bear Valley pipeline has to be moved down the shaft to generate electricity above the shaft through a 40 meter power supply line. Steel plates were laid under the shaft, and the base metal was demagnetized in advance in consideration of the impact of magnetic fields on the electric arc. Due to the careful consideration and arrangement of the construction environment and welding process parameters by the project team in advance, the double inspection qualified rate of 31 crossings was ensured to be 100%.