Cold, colder, Oulu: At -15 degrees Celsius in November the team from Brandenburger Liner GmbH & Co. KG in Landau and Putkistosaneeraus Eerola Oy in Finland installed two 16 tonne liners in a sewer beneath the Finnish city. This was quite a feat under these chilly conditions not only for the workers, but the technology too defied the cold.
Translated, Oulu means "flowing water". Recently the Putkistosaneeraus Eerola team ensured that water can flow again without difficulty through the sewer in the northernmost city in the EU. At a crisp -15 degrees, two liners with DN 1000 and 14.7 millimetre wall thickness respectively had to be installed along a length of 166 meters.
The refrigerated lorry became a heated lorry
Using water drainage, the Brandenburger Liner and Eerola employees diverted the wastewater into a second collection drain. Then the liner was drawn out of the refrigerated lorry into the shaft. For transportation to Scandinavia the liner, which must be stored at between 5 and 30 degrees Celsius, was transported by lorry on its journey from Landau to the construction site at a cool 17 degrees. This makes it easy to install and sufficiently erect so that it does not collapse when the light chain is being installed. Once in Oulu the refrigerated lorry became a heated lorry, protecting the liner from the cold. There was after all a full 32 degree temperature difference between the interior of the lorry and the outside.
Particularly high stress requirements
The cold was not the only major challenge on this construction site. A total of 4 liners were installed – with a total weight of over 50 tonnes. The heavy weight of the individual pipe liners results from the particularly high stress requirements in Finland and the extremely large wall thicknesses required as a result.
Therefore Eerola counts on the pipe liners from Brandenburger and their patented wrapping technology. Due to the pre-impregnation of the individual glass layers in the first production step, each linear meter is thoroughly saturated with resin. This guarantees that the liner is completely impregnated across its entire length.
Pleased with the new system
In April of this year, Brandenburger Liner inaugurated its fourth customised winding system in the new production hall, where the company can manufacture pipe liners with a diameter of up to DN 1600. To date it has already produced more than 20 kilometres of pipe liner in the very large dimensions alone. "We are very happy with the new system and the quantity manufactured to date has exceeded even our own expectations", says managing director Michael Schloder.