BS ISO 21138-2. 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 2. Pipes and fittings with smooth external surface, Type A|Fittings (pipes), Sewage, Plastic pipes, Pipe systems, Piping systems, Polypropylene, Drainpipes, Polyethylene, Sewage engineering, Pipes, Performance, Unplasticized polyvinyl chloride, Sewerage, Drainage, Marking, Mechanical behaviour of materials, Manholes, Water supply and waste systems (building, Plastics, Underground, Pipework systems, Physical properties of materials, Sewers, Performance testing, Dimensions