KS M ISO 21138-3-2008 非承重地下排水和污水处理用塑料管道系统.未增塑聚氯乙烯(PVC-U)、聚丙烯(PP)和聚乙烯(PE)结构壁管道系统.第3部分:B型带有非平滑外表面的管道和配件
Plastics piping systems for non-pressure underground drainage and sewerage-Structured-wall piping systems of unplasticized poly(vinyl chloride)(PVC-U), polypropylene(PP) and polyethlyene(PE)-Part 3 : Pipes and fittings with non-smooth external surface, Ty