1. District heating pipes. Bonded twin pipe systems for directly buried hot water networks. Factory made twin pipe assembly of steel service pipes, polyurethane thermal insulation and one casing of polyethylene Part 1, (5th November 2019) Authors: British Standards Institution, Record Type: Book Extent: 1 online resource (18 pages) View Content: Available online (eLD content is only available in our Reading Rooms) ↗