NEW PIPE LINE CONSTRUCTION TECHNIQUE IN EXISTING PIPE LINE

摘要

PROBLEM TO BE SOLVED: To weld seam part while restoring a shape of a metallic pipe from convolved-shape to circular shape manufactured initially and to reduce the trouble and time for jointing with welding by inserting continuously into an existing pipe line which opens in a work pit a convolved-shape metallic pipe of its outside diameter reduced and forcedly passing through the pipe a pipe enlarging apparatus mounted with an automatic welding machine. ;SOLUTION: A steel pipe 5 is inserted from a work pit 2 into an existing pipe line 6 which opens in the pit 2, for example, by a drawing-in of a pull rope 8 resulting from actuation of winch 7 in the condition of convolved-shape, that is, of the outside diameter reduced. To restore a shape of a convolved-shape pipe 5' and weld a seam part, a pipe enlarging apparatus 10 mounted with an automatic welding machine 9 is passing forcedly through the steel pipe 5', for example, by the drawing-in operation of the pull rope 8 resulting from actuation of winch 7. The automatic welding machine 9 welds both edge parts. Thereby, a new pipe line which consists of the steel pipe 5 can be constructed in an existing pipe line.;COPYRIGHT: (C)1997,JPO