METHOD FOR TRENCHLESS REPLACEMENT OF PIPELINES AT LOW TEMPERATURES Russian patent published in 2024 - IPC F16L1/28 

FIELD: construction.

SUBSTANCE: invention relates to construction industry and can be used for trenchless replacement of old underground pipelines for various purposes, including at low temperatures. Method involves placing a new plastic pipeline in guide clamps (centralisers), welding of new plastic pipeline, elimination of old pipeline, pulling of new plastic pipeline into installation well through flexible corrugated heat-insulating sleeve. Between the heat-insulating sleeve and the new plastic pipeline hot air is supplied to heat the new plastic pipeline to the temperature not higher than the temperature of the beginning of plastic deformation of its material. Prior to welding of new plastic pipeline, heat-shrinkable tape is tightly glued to its welded ends. Then a tool is installed between the ends to heat the ends to normal ambient temperature. Thereafter, the tool is removed, butt ends are jointed together, and ultrasonic welding of the new plastic pipeline is performed by means of a waveguide. Waveguide is moved along the butt joint along a circular path manually or with the help of a mechanized device. In the presence of sediments, welding of a new plastic pipeline is carried out in a tent.

EFFECT: method makes it possible to increase reliability of trenchless replacement of pipelines at low temperature of ambient air and presence of precipitation.

1 cl, 4 dwg