| 摘要 |
This invention is intended for a combined drainage and rainwater pipe 1, which is characterised in that the pipe 1 is completely circular in cross-section and provided with a double wall with a corrugated outer layer 2 and a smooth inner layer 3, that the wall of the pipe 1 is completely closed on its bottom side, and on its upper side is provided with holes 4 situated at the bottoms of the corrugations and an installation line 5, which extends in the longitudinal direction of the pipe. <IMAGE>
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