PIPELINE CUTTING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a pipeline cutting method eliminating the possibility of ignition and damage of a new pipeline and reducing the working man-hours. SOLUTION: This method for cutting an established pipe 1 and forming an opening for exposing the established pipeline 2 when providing a branch takeoff connection in a part of the pipeline 2 newly laid in the established pipe 1, a cutting device 3 having a shear blade 3C positioned in the existing pipe 1 and cutting the circumferential wall by a shearing force in holding the circumferential wall while moving circumferentially with the newly laid pipeline 2 outer circumferential face set to a guide face is arranged in a part of the existing pipe 1 corresponding to the branch takeoff connection. This method is characterized that the circumferential wall is cut by moving the cutting device 3 along the circumferential direction of the existing pipeline 1 while discharging cut pieces T in the cut position outward of the established pipeline 1.