对焊钢管 meaning in Chinese

buff-welded steel pipe

Steel butt - welding pipe fittings ; elbows and bends with reduced pressure factor
对焊钢管配件.第1部分:压力减缩系数弯头和弯管
Steel butt - welding pipe fittings ; reducers for use at full service pressure
对焊钢管配件.第2部分:满工作压力条件下使用的减压器
Steel butt - welding pipe fittings ; eccentric reducers with reduced pressure factor
对焊钢管配件.第1部分:压力减缩系数的偏心减压器