Plastic pipe systems for district heating

Plastic medium pipes have in some countries been used for many years in floor heating applications and in smaller local networks. In Denmark, these pipes are also quite common for smaller pipelines in district heating networks. In spite of years of experience, there still exist doubts about the possibilities of using plastic pipes in district heating applications, mostly because of the limitations in pressure and temperatures which must be observed when using plastic medium pipes. The use of plastic medium pipes is also limited to relatively small dimensions, which makes it necessary to mix steel pipes and plastic medium pipes in many applications, a combination for which experience so far was not systematically documented.