DIN 4741-5
DIN 4741-5
Ventilation plant; polypropylene (PP) pipes, type 1; non-reinforced ducts; minimum wall thicknessstandard by Deutsches Institut Fur Normung E.V. (German National Standard), 09/01/1988
standard by Deutsches Institut Fur Normung E.V. (German National Standard), 09/01/1988