Bassewitz, Janson, Liebel
Hot Water # 2006 Washington DC
From Jan 6th 2001 until March 31st 2005 a research project, funded by the German Ministry for Economy and Research had been carried out in order to investigate technical details not yet researched. The results of the project have shown that polymer flexible pipes for district heating are fit for purpose.
The research project focused on district heating pipes with PE-X and PE-RT service pipes, semi-rigid PU foam and a PE casing.
Whilst for district heating pipes with steel service pipe, rigid PU foams and HD-PE jacket pipes all relevant material properties have been proven to be fit for purpose, this had not been done for the flexible pipe systems in question.
The questions to be answered have been :
- Are the PE-X and PE-RT service pipes able to withstand the temperature and pressure conditions of typical district heating systems, including the effect of oxygen in the water?
(The current standards applicable for PE-X pipes and their applications do not cover these conditions)
- Which heat aging properties does the semi rigid foam have, and how does the coefficient of heat transport change with time?
- Are the semi rigid PU foams able to withstand the thermal and mechanical actions during the lifetime, without loosing the bonding between the pipe components?
The participants of the reearch project had been: GEF Ingenieur AG (Project leader), REHAU, Borealis, Elastogran, Huntsman, Stadtwerke Lemgo, Uponor, Wärmeversorgung Südbayern, Becker Plastics, BP Solvay, DREWAG, GeorgFischer, Logstor, FernwärmeForschungsInstitut, IMA Dresden, Ingenieurtechnik Hessel.