27 November 2018

Odeonsplatz square is located on the edge of Munich’s old town, in the center of the pedestrianized shopping zone; it is a popular location for events, a well-known meeting point, and a tourist attraction, and not an ideal location for a construction site.
But when works on the square became inevitable – to supply the stores around Odeonsplatz with district heating – the Munich authorities made the smart decision to opt for FLEXWELL district heating cables. Due to the conditions on site, a solution with any other pipeline – if feasible – would have been complex and long-winded to install.

From a technical perspective, the route was fixed from the start of the project. In some places, the cables would need to be laid at a depth of just 60 cm. In other areas, the trench was just 45 cm wide, creating a challenging installation scenario with pipes varying in diameter between 22 and 17 cm. The construction site workers also had to avoid the suburban train and pedestrian tunnels and many other pipes, lines and cables.

Thanks to their steel-shell structure, FLEXWELL district heating cables can be laid at depths of less than 60 cm. FLEXWELL district heating cables are self-compensating, which means that the system automatically compensates for changes to length resulting from thermal requirements.
Unlike with rigid pipelines, there is no need to install expansion bends or buffers. The helically corrugated surface allows FLEXWELL pipes to independently vent themselves. The ventilation fittings required for other pipe systems, due to the differences in height across the pipeline length, are not needed. The flexibility of the pipe enabled the installers to simply avoid any obstacles in the ground – by routing the pipe around, under or above them – without needing to install any other molded parts.

And last but not least: FLEXWELL is delivered and laid in one piece, cut to the exact length required on the construction site. There is no need to weld pipes together or isolate joints underground – which would not have been possible anyway due to the space constraints in this project.

The decision to use FLEXWELL district heating cables was a major factor in the success of the project: Ultimately, the Munich authorities were able to expand the city’s district heating network by around 200 m and refill the trenches dug in Odeonsplatz in the space of a week.

Summary: Laying of 2 x 96 m FHK 127/220 and 2 x 21 m FHK 98/171 within the space of five days under Odeonsplatz in Munich. The network of other pipes, lines and cables and below-ground structures meant frequent changes of direction and installation
height. The project was made all the more challenging by the tight schedule. The conditions served to highlight all the advantages of the FLEXWELL district heating cable.