热镀锌钢管标准

热镀锌钢管标准：DN250 б=7.0mm DN200 б=6.0mm DN150 б=4.5mm DN125 б=4.0mm DN100 б=4.0mm DN80 б=4.0mm DN65 б=4.0mm DN50 б=3.8mm DN40 б=3.5mm DN32 б=3.5mm DN25 б=3.2mm DN20 б=2.8mm DN15 б=2.8mm