Butt Welded Pipe Fittings Cross(GB12459)

　　The pipe wall thickness grade is indicated by the pipe number, the common pipe number is Sch40 and Sch80. When selecting the welded pipe fittings, the pipe should be the same as the pipe number of the pipe to which it is connected, that is, the strength of pipe and pipe, Thick), except that the wall thickness of the end of the pipe is the same as the wall thickness of the pipe. China's National Standard for Steel Butt Welded Pipe Fittings Cross(GB12459) and China Petroleum & Chemical Corporation Standard (SH3408) are basically the same as ASME B16.9, B16.28, JIS, JPI-7S and JPI-7S-1.