New smaller thermoplastic pipes are welded on the job site and inserted into the existing pipe through a construction pit. An annular gap that is usually filled-in is left between the old and the new pipe. This results in a reduced cross-section.
Fields of application:
- Depending on pipe material suitable for pressurized and non-pressurized pipelines
- Drinking and waste water, gas and industrial applications possible
- All pipe materials and dimensions suitable for pulling and insertion can be used
- The constuction pit must be dimensioned according to pipe size, the material used and installation depth.
- Circular profiles
- DN 80 – DN 1400 mm
Advantages:
- Short construction time
- Shafts without curved channels can be passed through
- Use of factory-manufactured pipes and components with defined material properties.
- The pipe is hydraulically very smooth and resistant against aggressive waste water and mechanical stresses
Disadvantages:
- Significant cross-section reduction
- Filling of the annular gap is usually required
- Earthworks for the construction pit
- High-quality welding of pipes needed
- Significant space requirements for the pipe-string lay-out during welding
- Not suitable for damage such as position deviation and pipe collapse
- High-quality re-connection of house connections via excavation method
