| 摘要 |
PURPOSE:To weld satisfactorily pipes having different circumferential lengths in the stage of welding circumferentially the pipes having a dislocation between the inside surfaces by subjecting the inside surfaces of the pipe ends to build-up welding to a specific thickness then working the build-up weld zones to the true circle having the same inside diameter. CONSTITUTION:The inside end surface of the pipe A having a short inside diameter dAs and long inside diameter dAl is subjected to build-up welding to >=(dAl-dBs)/2 thickness and the inside end surface of the pipe B having a short inside diameter dBs and long inside diameter dBl (dAs>=dBs) is subjected to the build-up welding of >=(dBl-dBs)/2 thickness in the stage of welding circumferentially the pipe A and the pipe B. Only the build-up weld metals of both pipes A, B are then machined over the entire circumference to the true circle and the inside diameter thereof is made within the same diameter below dBs. The pipes A, B subjected to such pipe end working treatment are butted to each other and circumferentially welded, by which the dislocation between the inside surfaces is eliminated at all. |
