| 摘要 |
The present invention relates to pre-insulated pipes for e.g. district heating, district cooling etc., said pipe comprising a medium conveying pipe, an insulating material surrounding at least a part of the length of the medium conveying pipe and a jacket pipe at least partly surrounding the insulating material. The novel aspects include that the pipe comprises a layer of polymeric material at least partly surrounding the insulating material, the layer of polymeric material comprising at least one layer of a material or combination of materials being permeable to water or water vapour, and having significantly better properties than PE for resistance against diffusion of oxygen and carbon dioxide, where said material or combination of materials includes at least one of the materials PVDC, PA and EVOH. By the invention it is obtained that any water vapour is allowed to escape from the insulation material, but also that carbon dioxide is kept within the insulation material and thereby avoiding an amount of ambient oxygen to build up in the insulating material. |
