05/03/2024

Horizontal directional drilling under the Reuss and A14 - PREMANT pipe laying for the Ennetsee heating network

Near the Swiss municipality of Inwil, we laid our corrosion-resistant PREMANT pipes under the river and the highway in order to provide residents with an optimal supply of thermal energy in the future and to drive forward the extensive expansion of the Ennetsee heating network.

The construction project went through several stages. Together with the civil engineering department and the pipe installer, we expanded the 2.5-kilometre section. The energy for the heat supply comes from the Perlen waste incineration plant. The special feature of the construction site was that there was a section where the PREMANT pipes had to be laid under the A14 highway and the Reuss. The horizontal directional drilling method with a total length of 900 m was used to ensure that the highway and the river were not damaged.

In this flush drilling process, two of our DN 250 pipe rods with a length of 16 meters were always transported to a ramp and then gradually pulled into the empty pipes of the starting pit. The biggest challenge on the construction site was not only the time-consuming pulling of the supply and return pipes into the empty pipes, but also the welding and fitting of the sleeves. After the 16-meter pole had almost disappeared into the ground, the next pole was loaded onto the ramp at the same time. Connecting the two poles together was a challenging job that took over 20 days, especially as only four sleeves with welded seams could be created in one day. However, despite the challenges on site, our fitters successfully completed the job.

The rigid PREMANT long-distance pipe is robust and corrosion-resistant. Thanks to its design and material properties, this pipe system is ideal for transporting heating water over straight distances. The integrated monitoring wires round off the product and provide additional safety.

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