MUD FEED AND DISCHARGE PIPE CONNECTING METHOD

摘要

PURPOSE: To remove a mud feed pipe and a mud discharge pipe from a pipe joint part at the time of connecting a propulsion pipe so as to positively weld and joint even the propulsion pipe with small bore. CONSTITUTION: A mud feed pipe 4 and a mud discharge pipe disposed in a propulsion pipe are connected to each other by an expansion joint 11a expanded by one propulsion pipe part. At the time of propelling the pipe, the expansion joint 11a is elongated to dispose the mud feed pipe 4 and mud discharge pipe in the whole pipe to be propelled. At the time of connecting a new pipe 8a to the propelled existing pipe 8, a mud feed pipe and a mud discharge pipe disposed in the new pipe 8a are connected to the mud feed pipe 4 and mud discharge pipe disposed in the existing pipe 8a. The expansion joint 11a is then contracted, and the centering of the existing pipe 8 and new pipe 8a is performed to weld the existing pipe 8 and new pipe 8a to each other.