... 2006,ISO4422-1996 standard,GB StandardAdvantage:A. PVC-U is a rigid unplasticized material with good surface rigidity and tensile ... chemical resistance including acids, alkalis, salts resistance, suitable for sewerage and industrial effluent disposalD.Low coefficient of friction fo ... adopted, easy to handle and install.Photos White rigid pvc water perforated plastic U-PVC hdpe perforated drainage pipe