DIN CEN/TS 13598-3

Plastics piping systems for non-pressure underground drainage and sewerage – Unplasticized poly(vinyl chloride) (PVC-U), polypropylene (PP) and polyethylene (PE) – Part 3: Guidance for assessment of conformity; German version CEN/TS 13598-3:2012
standard by Deutsches Institut Fur Normung E.V. (German National Standard), 07/01/2012