钢管的基本尺寸和公差 单位为毫米公称尺寸DN系列II系列外径D壁厚S外径D壁厚SPN25PN16PN25PN161012.70.100.80.080.60.0615.00.100.80.081516.00.101.00.100.80.0818.00.101.00.102020.00.111.00.1022.00.111.20.121.00.102525.40.1428.00.143232.00.171.20.1235.00.171.50.151.20.124040.00.2142.00.215050.80.2654.00.266576.10.381.50.2076.10.382.00.201.50.158088.90.442.00.2088.90.442.00.20100101.60.512.00.20108.00.54125133.00.993.00.302.50.30150159.01.19200219.01.643.50.303.00.30250273.02.054.00.30300325.02.44