For this procedure standard PE-HD pipes are welded to a string, then deformed on site and pulled into the existing pipeline.
The cross-section is reduced for pipes deformed on site by means of a mechanical working process carried out by the customer. In the course of this welded standard PE pipes are pulled through a reduction tool and the cross-section is thus reduced by 25% - 30% to facilitate the introduction of the new pipe into the old one.
After insertion the pipe expands again and gets a close fit to the existing pipe. The cross-section is only slightly reduced compared with the old pipe (twice the wall thickness of the liner pipe).
The pipes are exclusively installed via correspondingly dimensioned trenches.
Fields of application:
- Suitable for pressure and open channel pipelines
- Drinking and waste water, gas and industrial applications are possible
- DN 100 - 1500 mm.
- Circular profile
- Material: PE-HD
- Lateral connection mostly in cut-and cover construction method or with specific welding suitable cap profiles for PE-HD liners for waste water applications
- Calibration of old pipes required
Advantages:
- Short construction time
- No remaining annular space; no filling required
- Insignificant cross-section reduction (twice the wall thickness of the liner pipe)
- The liner is hydraulically very smooth and resistant against aggressive waste water and mechanical stresses;
Disadvantages:
- Earthworks for trenches required
- High-quality welding of pipes necessary
- Significant space requirements for laying-out the pipe-string;
- Risk of incomplete recovery (folding) of the new pipe - particularly in the case of position deviation, drift and nominal dimensions tolerances in the old pipe;
- Not suitable for damage such as position deviation and pipe collapse
