Since 1991 more than 600 km of pressure pipelines with diameters between DN (nominal diameter) 100 and DN 600 have been successfully relined for local gas suppliers using the starline®2000 technology that has been designed and patented by Group of Karl Weiss.
The technology has been approved by DVGW up to an operating pressure of 4 bar and fulfills all requirements of DIN 30658 part 1 (Means for the belated sealing of underground gas pipelines).
The integration of the DVGW (German Association of Gas and Water Engineers) worksheet G 478 (Rehabilitation of gas pipelines by fabric hose relining – requirements, quality assurance and inspection) guarantees the expert workmanship of every rehabilitation. Additionally, our own quality assurance procedure has been created in the course of the processes.
The starline® fabric hose technology is therefore one of the rehabilitation procedures with the highest quality level available worldwide.
The pipelines are generally cleaned by sand-blasting. Cleaning the inside wall of the pipeline thoroughly is an essential prerequisite for a high-quality rehabilitation. For contamination that cannot be removed by sand-blasting Group of Karl Weiss has developed an ultra-high water cleaning procedure. In this procedure, an extremely high pressurized water jet cuts the impurities off the pipeline wall without damaging the wall in the process.
For the rehabilitation of drinking water services this fabric hose procedure has been further developed to starline®1000 technology. The starline®1000 technology fulfills all inspections that are required in Germany with regard to drinking water hygiene:
- Guidelines for the health implications of plastics and other non-metal materials within the limits of the food and commodities law with regard to drinking water (abbreviated: KTW guidelines),
- Requirements of the DVGW worksheet W 270 “The breeding of microorganisms on materials used for drinking water appliances”.
Crucial advantages of a rehabilitation using the starline® technology are speed, profitability, reliability, and ecofriendliness.
Due to the use of mobile rehabilitation units, rehabilitation works can also be carried out in inner city areas where there is little space to maneuver and where rehabilitation vehicles do not have direct access.
After the rehabilitation itself has been completed, which takes only about one hour for a section with a length of 200 m, the rehabilitation unit can be disconnected from the rehabilitation section and can therefore be used for several rehabilitations in one day.
Subsequent curing of the adhesive system can take place at ambient or elevated temperatures:
- The cold curing adhesive system (ambient temperature) hardens during the night. As a result, the rehabilitated pipeline can be put back into operation after approx. 1 to 1 ½ working days.
- When using the warm curing system, the pipeline is heated up by adding hot water and hardens within a few hours. The relined pipeline can then be put back into operation after approx. 12 to 15 hours. This is of particular interest for drinking water services because there is no need for expensive compensation supplies.
After the adhesive is hardened, the existing tees and services are opened trenchlessly by a TV-assisted robot system developed by us. The necessary construction works are therefore reduced to small excavations at launch and target pits along the mains. They are positioned at distances of 150 to 250 m according to the diameter.
Due to a continuous development and new design of the starline® technology the existing procedures are continuously optimized and adjusted to the requirements of the market. New hose procedures for all mediums and pressure rates are also being developed. Due to constantly increasing costs and the increasing number of environmental regulations imposed by the authorities, the fabric hose technology will be used more and more in inner city areas compared with the conventional open construction.