ISO 21138-2:2007, together with ISO 21138-1, specifies the definitions and requirements for pipes with a smooth external surface (Type A), fittings and systems based on unplasticized poly(vinyl chloride) (PVC-U), polypropylene (PP) and polyethylene (PE) structured-wall piping in the field of non-pressure systems for underground drainage and sewerage.

ISO 21138-2:2007 specifically refers to PVC, PP and PE materials

ISO 21138-2:2007 specifies test methods and test parameters.

ISO 21138-2:2007 covers a range of pipe and fitting sizes, materials, pipe constructions, and nominal ring stiffnesses, and gives recommendations concerning colours.

In conjunction with ISO 21138-1, it is applicable to PVC-U, PP and PE structured-wall pipes and fittings, to their joints and to joints with components of other plastics and non-plastics materials intended to be used for buried piping systems for the transport of drainage and sewage.

ISO 21138-2:2007 is applicable to PVC-U, PP and PE structured-wall pipes and fittings with or without an integral socket with elastomeric ring seal joints as well as welded and fused joints.