This document specifies the requirements for solid wall pipes with smooth internal and external surfaces, extruded from the same formulation throughout the wall, fittings and the system of unplasticized poly(vinyl chloride) (PVC-U) piping systems intended for soil and waste discharge applications (low and high temperature): — inside buildings (application area code “B”); — for both inside buildings and buried in ground within the building structure (application area code “BD”).