Abstract: As time goes on, the pipeline coating will get to age in varing degrees, which leads to the perforation and leakage of pipeline. In this case, rehabilitation of pipeline and replacement of corroded pipe section have to be made. During the replacement, pipeline is insulated, then purged. Only after finishing these can the hot work (welding) begin. The paper overviews the insulation, purging, and steps of hot work for long distance pipeline and pumping station pipeline.