镀锌焊接钢管，国标GB／T3091—2001。公称直径DN 外径Dw镀锌焊接钢管，国标GB／T3091—2001。外径Dw壁厚（普通)壁厚（加厚）壁厚（普通)壁厚（加厚）公称直径DN 1520253240506580100125150单位mm。21.326.833.542.3486075.588.51141401652.752.753.253.253.53.53.75444.54.53.253.5444.254.54.54.7555.55.51520253240506580100125150单位mm。21.326.833.542.3486075.588.51141401652.752.753.253.253.53.53.75444.54.53.253.5444.254.54.54.7555.55.5热轧扁钢标准. GB 704-88热轧扁钢标准. GB 704-88
