Method for relining an underground gas line or the like without excavation

摘要

A method and apparatus for repairing or relining an underground pipeline without having to excavate the pipe is enabled by attaching an expandable sealing unit to the end of a predetermined length of flexible tubing and feeding it through the pipeline. The flexible tubing is fed through the existing pipeline from a point beyond where the existing pipeline exits the earth, usually within the basement of a building. Once positioned in the desired location, the expandable sealing unit is expanded to form a tight seal at the desired location within the pipe by means of heating the expandable sealing unit by a heating unit connected to the source of energy through electrical conductors which pass through the flexible tubing.