Method and apparatus for installing a new pipeline within an existing pipeline

摘要

A thermoplastic pipe 10 in a flattened configuration is formed either by manufacturing it in this reduced shape or by heating a round thermoplastic pipe enought to make it pliable and then reducing its cross sectional dimension (Fig 2 not shown). It is inserted in this reduced dimension and in a pliable state into a pipe 14 to be rebuilt. It is then expanded and when set serves as a rigid or semi-rigid pipe within a pipe. The thermoplastic pipe 10 is heated e.g. by a heater 18 during ist installation. The thermoplastic pipe eg of P.V.C. upon being reduced in dimension may be wound on a roll and unwound from such roll during installation. A heated pig or pulled plug x 50 (Fig 6) may urge the liner outwardly. Alternatively, hot pressure fluid fed between a pair of plugs 30, 32 provided with expandable gaskets 34 (Fig 5) may be used. IMAGE