BS ISO 21138-3. 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. Pipes and fittings with non-smooth external surface, Type B|Pipe fittings, Plastic pipes, Pipe systems, Piping systems, Manholes, Sewers, Pipes, Mechanical behaviour of materials, Performance testing, Sewage engineering, Water supply and waste systems (building, Physical properties of materials, Pipework systems, Dimensions, Plastics, Performance, Sewerage, Polyethylene, Polypropylene, Underground, Unplasticized polyvinyl chloride, Drainage, Drainpipes, Marking