Effects of mechanical loads on ageing of prefabricated district heating pipes

The focus has been on pre-insulated steel district heating pipes, with particular emphasis on how mechanical loads accelerate degradation. The study analysed deterioration in the field, especially where the insulation separates from the media pipe, which can lead to fatigue and leakage. Experiences from other failure mechanisms have also been compiled. In parallel, new methods have been developed for assessing lifespan and status, through laboratory testing, to enable smart maintenance and selective replacement of worn-out components. The aim was a more reliable calculation model for remaining service life based on actual field conditions.