DIN 16875
DIN 16875 Pipes and fittings of unplasticized poly(vinyl chloride) (PVC-U) for ducting - Dimensions and technical delivery conditions
standard by Deutsches Institut Fur Normung E.V. (German National Standard), 03/01/2013
standard by Deutsches Institut Fur Normung E.V. (German National Standard), 03/01/2013