钢管公称直径与外径的对应关系 DN的含义:代表管材的公称直径 字符Ф:代表管材的外径表示 DN15-ф22mm,DN20-ф27mm DN25-ф34mm,DN32-ф42mm DN40-ф48mm,DN50-ф60mm DN65-ф76(73)mm,DN80-ф89mm DN100-ф114mm,DN125-ф140mm DN150-ф168mm,DN200-ф219mm DN250-ф273mm,DN300-ф324mm DN350-ф360mm,DN400-ф406mm DN450-ф457mm,DN500-ф508mm DN600-ф610mm, DN15-ф18mm,DN20-ф25mm DN25-ф32mm,DN32-ф38mm DN40-ф45mm,DN50-ф57mm DN65-ф73mm,DN80-ф89mm DN100-ф108mm,DN125