| 摘要 |
<p>Pipelines for district heating systems consist of a metal pipe carrying the heating medium and an outer plastic tube, with the space between filled with plastic foam. To produce a through joint or a branch joint, the foam is partly removed and the metal pipe ends are welded together. A sleeve is applied to the inside of the outer covers and an other sleeve to their outside. Both have holes so that plastic foam can be injected to fill up the hollow space. After the hole in the inner sleeve has been closed, the space between the two sleeves is filled by a sealing cpd. Tube is pref. of plastics, esp. of polyethylene or PVC. Joint is an effective seal against water ingress.</p> |
