The 15th Wiesbadener Kunststoffrohrtage (Wiesbaden Plastic Pipe Days), held in April 2011, served as an international forum for polymer-based pipe systems. A notable presentation by Dr. J. Hessel focused on the long-term behavior of welded joints in large polyethylene pipes, addressing the testing challenges associated with the development of large pipes and their butt-welding connection techniques.