seen for the renovation of markforlagda rorledningar

摘要

Method for restoring underground pipeline (11B) wherein short-pipes (17) are pressed one after the other intermittently into the pipeline end to end. An expansion piercer (18) or similar broaching tool is pushed through the pipeline at the leading end of the pipe string formed by the short-pipes and is brought to expand so as to split or, if splitting is not necessary, to widen the pipeline to substantially circular cross-sectional form.