| 摘要 |
A large-diameter hollow body, especially pipe such as waste or sewage pipe, consisting of a multiplicity of helical turns of an extruded thermoplastic synthetic-resin hollow strip heat-sealed together in laterally abutting relationship. The thermal butt welds are provided in planes transverse to the axis so that the inner surface has turns which are flush with one another. The turns themselves are hollow and of a generally rectangular profile with a substantially round (preferably circular) inner cross-section. |
