NBN ENV 1401-3:2001

This Prestandard, together with prEN1046:2000 and EN1610:1997, provides a material-specific set of guidelines for the installation of piping systems made of unplasticized poly(vinyl chloride) (PVC-U) in the field of non-pressure underground drainage and sewerage - outside the building structure (application area code "U"); - both buried in ground within the building structure (application area code "D") and outside the building. This is reflected in the marking of products by "U" and "UD".