The procedure has a DIBt approval with the approval no. Z-42.3-453. By means of this sectional renovation method, also referred to a short liner, a fibreglass fabric mesh soaked with reaction resin, which is reeled onto the renovation packer sized to the corresponding nominal width, is pushed to the damaged renovation area by means of an air-driven push rod or pulled by means of a rope.
The determination of the exact position of the damaged area takes place by means of a previous inspection performed by a TV camera. Then the renovation packer (rubber bubble) is provided step-by-step with compressed air. Due to the expansion of the packer body, the impregnated fibreglass fabric mesh is non-positively pressed to the interior wall of the pipe, whereby the excess reaction resin penetrates the damaged areas, thus hardening into a permanently self-supporting static system.
As the damaged area is covered over the full surface by the hardened fibreglass fabric mesh, the “Pipe in pipe system” does not present a hindrance for the flow and withstands the hydraulic requirement. The curing of the fibreglass fabric mesh soaked in reaction resin takes place by cold setting in accordance with the processing instructions. It must be observed that the hardening time required depends on the respective sewer atmosphere.
After the curing process, the compress air is released from the renovation packer and extracted from the pipeline. The renovated area must then be subjected to a final inspection by a mobile TV camera – this procedure is to be documented. The leak tightness test takes place acc. to DIN EN 1610.