Gas mains require careful handling.
Gas is a fossil fuel and an important natural resource for heating both residential and commercial spaces. However, because gas is flammable, explosive, colourless and usually odourless, it is essential that it is handled with care. At Kraft&Wärme, our specialists are rigorously trained to do exactly that and possess extensive expertise in laying gas mains.
We can use both open-trench and trenchless techniques to do so. We will always find the right solution for your project based on the pipe material, whether it is PE or steel.
Open-trench pipeline installation.
Laying pipes in open trenches is, of course, the conventional method and has been among our specialities for decades. The team at Kraft&Wärme is fully trained in how to lay pipes of all dimensions and materials. We also perform repairs on any existing piping, of course.
Trenchless pipeline installation.
In addition to the open-trench method, we also possess profound expertise in the field of trenchless pipeline installation. Depending on the specific requirements of each project, we choose one of the following techniques:
Pipe bursting method/Pull-in-place method.
The static pipe bursting method is a modern, cost-effective method that makes it possible to increase pipe dimensions compared to existing pipework. We can replace or restore underground pipes made from metallic or fracturable materials such as PE, steel, grey cast iron, PVC and fibre cement without any vibrations.
In this method, the traction rod is inserted into the existing pipe. The traction rod is fitted with a suitable cutting head for the existing pipe material at one end and a hydraulic towing unit at the other.
The traction rod thereby slices the old pipe and, as it progresses, a cone expands the pipe cross-section. Slicing and expanding at the same time makes it possible to move a new pipe into place and increase the dimension of the pipeline compared to the existing piping.
Lining method with annular space.
A cost-effective and, above all, straightforward alternative to pipe bursting is the lining method, which makes it possible to replace existing pipelines using either short-pipe or long-pipe sections.
The first stage in this case is to clean, calibrate and conduct an inspection of the pipeline with a camera. The next stage involves using a pull rope or traction rod to pull the new, smaller-diameter product pipe into the old pipe. This creates an annular space between the old and new piping, which can then be plugged if necessary.
The pull-in forces acting on the piping are documented with complete precision at all times to ensure that the permitted pull-in forces of the new piping material are not exceeded.
- Short-pipe lining: We use this method when the installation cavity is longer than the factory length of the piping to be installed. Pipe connections are then realised in the construction pit.
- Long-pipe lining: This involves welding pipe sections into a string outside the construction pipe before subsequently pulling it into the cavity.
Renewing pipes with Starline 200/2000.
At Kraft&Wärme, our team relies on the specially developed Starline 200/2000 system for projects to renew existing gas mains. The first stage involves sand blasting the pipes’ interiors to clean them. In the second stage, a fabric hose impregnated with two-component epoxy resin and a gas-tight internal coating is inserted using the inversion technique. We then initialise the curing process of the epoxy resin by circulating hot water in the system.
This makes it possible, depending on the system dimensions, to renew up to five 90°-bends per house connection, completely wrinkle-free. The fabric hose stuck to the pipe interior also forms a high-quality, dense lining that is only 1-2mm thick. The statics of the existing pipework is capable of absorbing the earth pressure.