ABSTRACT
ABSTRACT: For more than 20 years PA 12 is evaluated as a pipe material for gas distribution and for more than 10 years PA 12 pipes have been used for low pressure installations. In recent years PA 12 is being investigated for operation pressures above 10 bar. Since 2002 ISO/TC 138 is elaborating standards for PA 12 gas installation systems with operation pressures up to 20 bar. In 2007 the first three parts of the ISO 22621 were published. Evonik Degussa GmbH, Marl, Germany, as one of the four manufacturers of PA 12 and E.ON Ruhrgas are cooperating on a test installation of a 60 m pipe system (110 mm SDR-11) in the technical center of E.ON Ruhrgas in Dorsten, Germany. The system with various connections was installed in October 2005. After 2 years operating at a pressure of 24 bar first samples were taken and investigated. The authors will give a report of the test installation and the experiences after 2 years. The paper will include also an introduction of the installation technology “Horizontal Directional Drilling” (HDD). In combination with the exceptional resistance of Polyamide 12 pipes against point loading and slow crack growth HDD offers new possibilities.
