非合金钢和合金钢对焊管件

[中文适用范围]： 第二版取消并取代了第一版（1975 年）。 规定了弯管/2D型（90和180）和3D（45、90和180）/同心和偏心异径管、三通、盖帽和端头的非合金、低合金和合金钢的尺寸、公差和常用牌号符合管道工程的质量要求。 [外文原描述]： This second edition cancels and replaces the first edition (1975). Specifies the dimensions, tolerances and generally used grades of non-alloy, low alloy and alloy steels for bends /type 2D (90 and 180 ) and 3D (45 , 90 and 180 )/, concentric and eccentric reducers, tees, caps and ends with quality requirements as used for piping work.