In the municipality of Attiswill in Bern, three apartment buildings were linked together in a heating network. The members of the community supply the raw material for the central heating system themselves – wood from the nearby community forest.
As the topping-out ceremony for the building was imminent, the CALPEX pipe had to be laid at temperatures around freezing point. Additional measures, such as pre-heating the CALPEX pipe, helped with ensuring that the pipe could be installed without any problems. Now that the CALPEX pipe has been laid successfully, Rolf Steffen, team leader at Alpiq AG, is very much satisfied. “The project showed how cooperation between the installer, Meier Tobler and Brugg Rohrsystem AG worked from the planning phase right through to the execution phase. That’s exactly how I picture team work.”
Near the Hungarian border, in the city of Košice (eastern Slovakia) – which, with a population of 240,000, is the second-largest city in the country after Bratislava – the primary school has been connected to the district heating system. The project was realised by our distribution partner, engineer Stanislav Hanula (SERIO s.r.o), and his experienced employees, who safely laid the rings weighing over 600 kg in next to no time and immediately covered them with sand in accordance with local ordinances.
Our new, compact, mobile CALPEX processing device was developed in order to reduce the overall manpower for future projects. The device makes laying the large CALPEX dimensions considerably easier and requires just four people to lay the pipework.
The Abbey District in the Klosterviertel of St. Gallen (Switzerland) is a UNESCO World Heritage site and is home to important artistic treasures, as well as numerous cantonal and church institutions. Up to 100,000 visitors come to experience the 1200-year-old history of the Abbey District each year, primarily the baroque cathedral and abbey library with its manuscripts, some of which are more than 1000 years old. Existing PREMANT heating pipes were modernised with flexible solutions from BRUGG in a project with two construction phases.
From the heating system, two lines were built, which run transversely through the popular courtyard of the abbey. A 23 m line made up of two CASAFLEX 60/142 (DN 50) pipes supplies the bishop’s wing with heat. A 29 m line with two DHC 127/220 (DN 100) pipes brings heat into the cathedral and three CASAFLEX 60/142 (DN 50) pipes are used as return pipes to provide a comfortable level of warmth in the abbey school building, tower and deanery wing. The restricted access to the courtyard due to a small archway posed a particular challenge with this project. As a result, the pipes had to be unrolled in front of the building and pulled into the courtyard.
The pipeline was installed in August 2017. Brugg trained CVADRO’s own technicians before the pipes were laid. The entire system is to be put into operation in autumn as planned so that tourists can also visit in the winter. The flexible solutions from BRUGG really won the builder over thanks to the short laying times (just three days in total) and simple installation despite the restricted space in the courtyard.
The district heating network at the Veneto Institute of Oncology (IOV) in the historic centre of Padua was renovated. The renovation measures affected the entire heating and cooling system of the institute and the adjoining building, which was formerly the Ospedale Busonera but is now the IOV. This part of the building was connected to the heating system in the eastern part of the hospital premises and a new cooling system was also installed in this area. This was connected using underground pipes, which were laid without trenches.
To ensure that the existing listed historic foundation and infrastructure lines did not get damaged, a decision was made to lay the pipes without trenches.
The laundry facility was connected to the underground pipes, which were laid without trenches, from the heating plant in the eastern part. Under the hospital, the pipes were led back towards the surface, where the pipe for the systems (all underground pipes and the duct for medical gas pipes) was connected to another pipe. It is still underground and accessible for testing. The eastern branch reaches the oncology building, where the existing heating plant on the roof was upgraded. The western branch is connected to a new heating sub-system, which was built in existing rooms. 300 m of CASAFLEX pipes with a diameter of DN 80 were used.
As Brugg Pipe Systems Piacenza planned and coordinated the process of laying the pipes without trenches so successfully, the various supply lines could be laid underground without damaging the foundations of the listed historic walls of the city of Padua.
At the beginning of November 2019, FLEXWELL district heating cables were laid in Berlin-Buch, which was unusual for us.
Only a few, long-standing employees remembered a building project more than 20 years ago in Potsdam, where FLEXWELL district heating cable 147/220 had already been laid using the cable ploughing method.
This type of installation is particularly suitable for longer distances between residential areas, it is particularly fast and environmentally friendly.
Understandably, this requires unpaved areas that are hardly to be found in the urban environment.
While the ploughing method is quite common for laying cables of all kinds, cable protection pipes, drinking water, wastewater and gas lines, it is rarely used in the area of district heating.
The building project
Our customer, Vattenfall Wärme Berlin AG, had to establish a 400 m long connection to the existing district heating network in order to connect the residential area called "Allees des Chateaux". The quarter is located in the local recreation area of Barnim which borders Berlin to the north-east.
After consultation with the Berlin Forests Authority and the Environmental Office in Pankow, the route was selected to run under the Buch Forest.
The decision was made in favour of FLEXWELL district heating cables and the environmentally friendly ploughing method.
FLEXWELL was chosen because the pipe is available in a complete length of 410 m and neither socket connections nor expansion absorption measures would be necessary along the route. In addition to the short laying time, other factors in favour of the ploughing method were the lack of topsoil removal and only little soil compaction.
In order to protect the standing trees, the lines were to be laid underneath a forest path which is already intended for reconsolidation.
Carrying out the work
On 4 November, 2 drums each holding 410 m of FLEXWELL district heating cable FHK 147/220, DN 125 were delivered to Berlin-Buch by flatbed truck. The drums were unloaded by crane and then lifted into our drum trailer. Then the pipe was then pulled off along the future route and laid out.
The plough arrived on 6 November and started work early on 7 November. Ploughing in of the FLEXWELL district heating cables totalling 820 m in length was completed without any problems within only one day.
Photos X21.de – Reiner Freese
The existing district heating pipe needed to be extended to connect a DB building. enercity Netz GmbH used this opportunity to prepare for the network extension and to increase the dimensions for this area at the same time.
Bischofsholer Damm is one of the key access roads from the south and east of the greater Hanover area. As well as being busy with commuters during the morning and evening rush hours, it sees a high traffic volume over the entire day. As a result, the disruption caused by laying the district heating pipes needed to be kept as low as possible, both in terms of space and time. This was absolutely crucial when it came to choosing the FLEXWELL district heating cable, according to Hans Marten, surface coordinator for pipe projects at enercity Netz GmbH. Thanks to the flexibility and self-compensating properties of the pipe, the trench width and therefore the civil engineering work required could be kept considerably lower than if conventional plastic casing pipes were used. Access holes for making welds or post-insulation of sleeves are not required.
The FLEXWELL district heating cable is produced to be virtually continuous and is delivered in lengths that meet the needs of the site. U-bends for absorbing the longitudinal expansion induced thermally are not required in the line. The FLEXWELL district heating cable compensates for this expansion within the system. Another advantage of the pipe – in addition to the streamlined trench design – is the laying speed. Several hundred metres can be laid in one piece within a day without any problems. In this case, the pipes were laid in three construction stages in lengths of 2 x 69 m, 2 x 136 m and 2 x 41 m. The sections were each laid within just one or two days. Then all that needed to be done was to establish the connections at the respective pipe ends.
In winter 2017, BTB (Blockheizkraftwerks-Träger und Betreibergesellschaft Berlin GmbH) planned a district heating line to open up a new residential construction project referred to as Bohnsdorf. BTB is one of the largest district heating operators in the Berlin area. The company has been around for 25 years and boasts a district heating network with a line length of approx. 160 km. The main area supplied is the Treptow-Köpenick district in the south-eastern part of Berlin. The supply is generated and distributed by a power station network made up of the Adlershof and Schöneweide sites. In the aforementioned neighbourhood, a line length of 2.2 km to the feed in the Bohnsdorf area needed to be implemented (see general plan diagram).
One major challenge for the builders was crossing the A117 autobahn with its slip road and exit. As BTB already had experience of using FLEXWELL district heating cables (DHC) with the directional drilling method, this technology was the preferred solution and after professional planning work, this remained the case. BTB opted for five direction drilling sections in total. For this, directional drilling lengths of 150 m–190 m were implemented with delivery lengths of 165 m–235 m. Despite the unfavourable ground conditions, all sections were inserted on time. Around 1900 m of DHC 200/310 were installed overall for this building project.
Challenges included the reloading processes and delivering the drums with a diameter of up to 5.10 m in advance at the motorway interchange (see photo). Short-term problems during the implementation of the building project were resolved in a targeted manner and confidently during the weekly meeting with the builder, the civil engineer, the directional drilling company, the pipe builder and BRUGG Rohrsysteme GmbH. The successful management of the project was a real team effort, from material provision, production, technical planning, (Wolfgang Nehrkorn) and order processing (Carola Rust) right through to installation (Uwe Wilhelms and Mario LeClaire). A big thank you to all involved!
District heating at the Baltic Sea beach
The striking white buildings along the Baltic Sea beach are what give Heiligendamm its nickname of the “white town by the sea”. The “string of pearls” of white buildings has been supplied by a newly laid district heating line since 2017. Both old and new district heating lines run here, for which a total of €1.1 million was invested. The PSP DN 200 pipe was connected to the existing DN 250 plastic casing pipe close to the tracks of the Molli narrow-gauge railway. German Pipe PREMANT pipes and moulded parts were delivered and laid to cover a length of around 250 m.
As usual, there were some other supply lines to cross. In terms of statics, the pipe was measured for 16 bar. It was relatively easy to position the calculated U and Z expanders along Kühlungsborner Straße. Constructed from 1 x 2 m elbows, no installation sleeves were required. PREMANT and FLEXWELL
This situation changed between the spa building and the Grand Hotel. The areas between adjacent buildings and paths were narrow and a different method was required. The water, which is up to 110°C, flows here at a depth of up to 4 m. With the BRUGG district heating cable DHC, this section could be finished using directional drilling and without having to dig up paths, parking areas and lawns. The transition from PREMANT to FLEXWELL is key here. As a result of the 16 bar internal pressure, the expansion force at the ends is approx. 45 kN. To absorb this stress, the subsequent PREMANT pipes and moulded parts were statically measured.
Some of the force is absorbed by the surface friction, which amounts to approx. 4 kN/m. The majority of the counterforce, however, is achieved by means of the side compression of the PSP elbows against the ground. The steel casing of the FLEXWELL district heating cable is also helpful as it applies or transfers some of the counterforce. The third and fourth construction stage ran from the Villa Perle, which was completely reconstructed in 2013, to behind the Hotel Residenz. Another 600 m of FLEXWELL 200/310 pipes were buried, interrupted only by connection points and intersections. Pipes were shut off to establish the connection with the existing PSP pipe. To allow subsequent reconnection, there are six ball valves over an area of just 20 m². The “FWN-Aufrüstung Heiligendamm – 1. bis 4. BA” project (Heiligendamm district heating upgrade – construction stage 1 to 4) shows how an optimum line can be created thanks to the clever planning solution of combining rigid and flexible pipe systems. German Pipe compiled the static calculations. Flow temperature: 110°C
Nominal pressure: PN 16
BRUGG Tubes SAS (France) was able to add another particularly prestigious project to its portfolio. This was a joint project with Bouygues SA and involved the famous Longchamp horse racecourse in Paris (Hippodrome de Longchamp). The renowned racecourse was built in 1857 on the walls of the Abbey of Longchamp, which was destroyed during the French Revolution, and was inaugurated by Napoleon III. The racecourse hosts the annual Grand Prix de Paris.
Bouygues is the fifth-largest construction company in Europe and has its headquarters in Paris. The project involved a two-year framework contract. It involves a district heating network, as well as a cooling network, both 1500 m long. BRUGG Tubes SAS calculated the statics, while laying company STM carried out the welding work. At this site, the customer imposed special delivery requirements on us.
To ensure that the pipes could be unloaded comfortably and due to safety regulations on the building site (pipe storage on-site, see photo 1), a timber had to be inserted between each row of pipes, which is also used for storage. The trucks had to be opened from the top to guarantee speedy unloading. BRUGG Tubes SAS and the installer were able to meet these requirements. The trenches were extremely generous, which worked in their favour as they were able to carry out the work on the sleeves and the welding work quickly and without complications.
A steam pipe was installed between the incinerator and the paper factory. An 836 m intermediate piece could not be laid above ground for visual reasons and the overground pipe used could not be laid in the ground. A solution was required. Requirement: 220°C operating temperature DN 500, output 45 tons/hour
A steel casing pipe was laid. A FLEXWELL DN 100 made of 1.4404 steel was used for the condensate return. For the most part, 12 m parts were used for the 836 m stretch. Special parts were required for changes in direction. The flexible DN 100 condensate pipe was able to be laid in one piece between the shafts.