Plastics piping systems for non-pressure underground drainage and sewerage - Structured-wall piping systems of unplasticized poly(vinyl chloride) (PVC-U), polypropylene (PP) and polyethylene (PE) - Part 3: Specifications for pipes and fittings with smooth internal and profiled external surface and t
无压地下排水和排污用塑料管道系统.未增塑聚氯乙烯(PVC-U)、聚丙烯(PP)和聚乙烯(PE)的结构化壁管系统.第3部分:具有光滑内表面和异型外表面的管道和配件规范