人妻系列av久久五月天

焊管、镀锌管理论重量表(按GB/T3091-2001标准执行)外径mm壁厚mm最小壁厚mm焊管(6m尺)镀锌管(6m尺)公称内径mm重kg根重kgDN151/2 21.32.82.32.462.462.3621.3621.33.74.621.662.3621.3621.362.33.33.82.22.1821.42.1821.321.3621.3621.42.42.42.1821.42.32.1821.621.621.3621.33.33.82.32.1821.321.221821.421.621.621.3621.621.3621.621.3332.