hydros® - Trenchless replacement

Trenchless replacement and new installation of mains pipelines

For the renewal of distribution pipelines in urban areas, our hydros® technology offers distinct advantages. It is very economical, especially in confined spaces or with a high density of installed pipelines. A drastic reduction of earthworks, removal of old piping, and vibration-free works in the same channel are further 'green' features.

Customized, proven and efficient technical equipment is ready for use in the following applications:

hydros®PLUS: pipe replacement
The original is known as a press-pull process for exchanging pressurized pipes made of brittle materials.

hydros®STEEL: pipe renovation
Especially for the renewal of pipelines made of ductile materials. A special cutting expansion head is used with the hydros®PLUS extraction device.

hydros®STAR: installation of new pipes
An additional pilot drilling machine and if necessary a flush head can be used in this process for installing new pipes or replacing them with with larger dimensions.

Of course our trenchless technologies comply with all of the DVGW regulations for mains supply pipelines.

  • PLUS PLUS AZ
  • STEEL
  • STAR

hydros®PLUS: exchanging mains pipelines

A trenchless process for replacing drinking water and gas mains pipelines up to a diameter of DN 400 (400 mm) and with individual extraction sections of up to 150m in length. These individual extraction sections are subdivided into partial extraction sections of up to 50m by the necessary intermediate pits for mains connections, hydrants etc.

By using PE coiled goods, over 100m of pipeline a day can be laid. Contrary to other well known methods, the complete removal of the old pipe from the ground and the vibration-free method protect the roots of the vegetation from damage. This environmentally friendly feature has been awarded an innovation prize for environmental technology by the state of Berlin.
Furthermore, the trenchless exchange of asbestos cement pipes has been tested by the employers' liability insurance association for health and safety at work (Berufsgenossenschaftlichen Institut Arbeitssicherheit, BIA) and registered in the BGI 664 with identification number BT 13. Due to the extremely low noise emissions (<55 dB(A)) the environmental authorities of Berlin have granted a general 24 hour special permit for this method.

hydros®STEEL: rehabilitation of mains pipelines, not only of steel

A trenchless process for renewing drinking water and gas mains pipe lines with a diameter of up to DN 300 and sections up to 200m long. The hydros®STEEL method is based on the tried and tested hydros®PLUS method and is used for renewing steel pipes as well as ductile cast iron and plastic pipelines, preferably with PE pipes.

In this process the old pipe is separated with the cutting head and expanded. In the same process the new length of pipe is pulled in, preferably with a protective coating. The split old pipe stays in the earth as a protective cap for the new one.
The original diameter stays the same or can be expanded by one dimension. In certain cases it can be expanded by two dimensions, using a special technique.
Operating safety is guaranteed, as this method does not allow any closed cavities between the old and new pipe. When connecting residential and other pipelines to the mains, the protective cap can be removed quickly and safely using a special method.

hydros®STAR: laying new mains pipelines

The further development of hydros®PLUS technology is used for the trenchless installation of new pressurized pipelines with an exterior diameter of up to 600mm and section lengths of up to 100m. First a laser guided pilot bore is used to lay the new route precisely. Then the pipe is pulled in, either by soil displacement or controlled hydraulic ground excavation, depending on the dimension.

The combination of ordinary pilot boring technology and the hydros®PLUS method guarantees an economical and safe installation technique. Depending on the soil, the soil displacement method is used for pipelines up to DN 200.

For larger dimensions our hydraulic flush head is used to drive in the new pipeline route. Unlike other well-known pipe laying methods, this prevents erosion. As only water is used as a flushing material, this simplifies the process considerably as opposed to clay-based flushing liquids.
The use of the flush head with the hydros®STAR process means that pipes with large diameter differences can also be exchanged, for example replacing DN 100 with DN 400.

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