TPi July 2019

Cast iron pipes Since 2007, the operators of the Willingen ski area in the Sauerland region of Germany, have placed their trust in the Duktus cast iron pipe system in a project for the expansion of the winter sports area. With the BLS ® connection and cement mortar coating (ZMU), the ductile iron pipes have been providing the necessary quality and reliability for more than a decade, ensuring the smooth running of the snowmaking equipment on all the ski slopes. In 2018, the operators again invested in the expansion of the ski area. The most modern chairlift system in Germany was constructed as part of the project, and the existing snowmaking system was enhanced with an additional snow line between the mountain and valley railway stations. The winter sports area’s planning team again chose the cast iron pipe system from Duktus. The narrow lines run through a sensitive vegetation area protected by FFH (Flora Fauna Habitat) directives. The line width for the pipes had to be kept to a minimum and the construction work could only be carried out in sections, with immediate surface restoration. Only neutral building materials were allowed. In order to meet the nature conservation requirements, Duktus worked closely with the team responsible for the Willingen ski area. The ductile cast iron pipes from Duktus in nominal diameters of DN 80 to DN 300 with zinc coating with a 5mm plastic- modified ZMU, and an inner lining based on aluminate cement (ZMA), fulfilled each requirement. Special designs of the pipe system and the bendability of the sleeves by up to 5° simplified the installation and laying of the pipes in curves under extreme conditions. The ductile pipes are designed to permanently withstand water pressures of up to 100 bars, and guarantee the high safety requirements for the technical snowmaking operation. The ZMA inner lining is positioned in the pipes using a rotary centrifuge process and is highly compressed, making it resistant to limescale deposits and lime-dissolving waters. The ZMU outer coating eliminates the need for additional protective and bedding materials such as sand, and prevents pH accumulation in the soil, ensuring compliance with all FFH requirements. In order to further optimise the assembly and installation on-site, the Duktus application engineers and the construction teams from the companies involved carried out comprehensive training for the BLS system prior to the start of construction. A total of 16 km of lines made of cast iron pipes from Duktus were laid in the ski sports area around the Köhlerhagen slope and the Ettelsberg slope. Even in times of low snowfall, Duktus cast iron pipes ensure the long-term supply of snowmaking equipment, and take into account environmental protection requirements. The customisable fitting programme allows the use of cast iron pipes even under extreme local conditions. Duktus (Wetzlar) GmbH & Co KG – Germany

info@duktus.com www.duktus.com Vonroll Infratec AG – Switzerland www.vonroll-infratec.com

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