Standard specification for single - or double - welded austenitic stainless steel pipe 单或双焊接奥氏体不锈钢管标准规范
2.
4 double - welded groove joints shall have their root passes back gouged to sound metal on the reverse side before proceeding with welding on that side 双面焊接的坡口焊道，应在焊接前将该面底部焊道逆向刨削，直到其对面露出完好的金属。
