ABNT NBR ISO 21138-3-2021Plastics 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:Pipes and fittings with non

ABNT NBR ISO 21138-3-2021Plastics 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:Pipes and fittings with non-smooth external surface, Type B