Ludwig Pfeiffer

Building site Dresden – Project district heating Mickten

In Dresden we are currently laying for DREWAG – Stadtwerke Dresden GmbH District heating pipes DN 250 for supplying the district of Mickten.

Special challenges are the laying under the traffic junction of Leipziger Strasse, as above ground there is still car, tram and pedestrian traffic and the tight schedule associated with this. Ludwig Pfeiffer is responsible for lifting and welding (4h! per day) the pipes. Via a construction pit, 10m long pipes are lifted in piece by piece and pulled into the steel protective pipe via a rail system.

After the non-destructive weld seam inspection and the successful pressure test by DREWAG, the district heating pipeline can be insulated. In the late afternoon, the next pipeline sections are then lifted into the excavation pit.

The reason for the construction site is to connect even more areas from the districts of Mickten and Kaditz to the district heating network of DREWAG. Our experienced and motivated colleagues on site kept to the tight schedule and did an excellent job. We thank them for their commitment and dedication.

In the next construction phase, Ludwig Pfeiffer pipelines will be laid and connected in the underground district heating structure. DREWAG is investing over EUR 3 million in the electricity and district heating line.

Click here for the article in the Sächsische Zeitung.

Heat exchanger for a residential park

For Berliner Wasserbetriebe, we are building a heat exchanger within a wastewater pressure line with a total length of 240 metres, pipe in pipe. The diameters of the two pipes differ by 10 cm. Warm wastewater will flow inside and water used for heating will flow in the space between. After completion, the pipe will be connected to a newly planned residential park with apartment buildings.

Pipe freezing

A sewage pressure pipe GGG DN 350 could not be taken out of service due to several broken gate valves. In order to avoid an emptying of the entire sewage pressure pipe network, it had been decided to freeze the pipe in place. After five hours of cooling with -196°C cold liquid gas, the entire pipeline cross section was cooled down to -30 to -50 °C and frozen. The hazard caused by the permanent outflow of nitrogen was monitored throughout the works by using gas detectors, so that there was always enough oxygen available at the workplaces. After about three hours of installation, the defrosting process could be started. After several hours, the pipe cross section was de-iced again, so that the pipeline could be put back into operation after just 24 hours.

Important grid node receives new transformer station

The Sandtorstraße transformer station in Magdeburg is one of two essential feed-in points for the power supply of the state capital of Saxony-Anhalt. The transformer station from the 80s is now giving way to a completely newly planned and designed substation. The scope of works of the Magdeburg subsidiary Schottstädt und Partner in the realisation of the modern plant includes the excavation works and the construction of the empty conduit routes for the 110 kV cable systems. These are being carried out both in open cut and with horizontal directional drilling.

After delivery of the new transformer station in the fourth quarter of 2020, the plant building is to be completed by the end of the year. In spring 2021, the new 110 kV transformer station with the first tied 110 kV cable system will be connected to the grid.

© Renderatelier Architekturvisualisierung, Dimitri Klein

Waterworks Naunhof

The waterworks Naunhof 1 is located in the heart of the Leipzig district and was the largest and most modern groundwater pumping plant in Europe when it was commissioned in 1887.

In 2019, we were commissioned by Kommunale Wasserwerke Leipzig GmbH to carry out the necessary modernisation work, the construction and expansion of 31 wells and the replacement of the two catchment pipes.

The wells supply the city of Naunhof and the region of Leipzig. The renewal of the production wells is a reaction to the increased population growth and the resulting increased drinking water supply. Kommunale Wasserwerke Leipzig GmbH, one of our main customers in the region, invested in total € 9 million for the upgrading of the water systems.

Click here for the article (in german) in the LVZ of 06 May 2020.