Plastics piping systems for non-pressure underground drainage and sewerage. Unplasticized poly(vinyl chloride) (PVC-U). Specifications for pipes, fittings and the system|Softening point, Size, Dimensions, Drainage, Colour, Sealing rings, Deformation, Chemical-resistance tests, Stiffness, Leak tests, Pipe couplings, Recycling, Performance, Pressure testing, Unplasticized polyvinyl chloride, Marking, Thermal resistance, Shape, Water supply and waste systems (buildings), Testing conditions, Plastic pipelines, Plastics, Diameter, Designations, Underground, Sewers, Pipe fittings, Drainpipes, Impact strength, Spigot-and-socket joints, Dimensional tolerances, Length, Pipes, Thickness, Polyvinyl chloride