焊缝编号应根据管线介质流向进行编号，原则上应先主管后支管。

Welding seam should be numbered according to pipeline medium set, in principle, main pipe prior to branch pipe.

youdao

焊缝编号应根据管线介质流向进行编号，原则上应先主管后支管。

Welding seam should be numbered according to pipeline medium set, in principle, main pipe prior to branch pipe.

youdao