How to identify seamless pipe and welded pipe?

1. GB/T 8162-2008 (theoretical weight of seamless steel pipe galvanized steel pipe for structure). It is mainly used for general structure and mechanical structure. Its representative materials (brand): carbon steel, 20, 45 steel; alloy steel Q345, 20c galvanized steel pipe price r, 40Cr, 20CrMo, 30-35CrMo, 42CrMo, etc.

2. Steel pipe GB/T 8163-2008 (seamless steel pipe for fluid transportation). It is mainly used for conveying fluid pipeline on engineering and large equipment. The material (brand) of ceramic composite steel pipe is 20, Q345, etc.

3. GB/T 3087-2008 (seamless steel tube for medium pressure boiler with low seamless steel tube). It is mainly used for conveying low and medium pressure fluid in industrial boilers and domestic boilers. The representative material is 10 and 20 steel.

4. GB/T 5310-2008 (seamless steel tube for high pressure boiler). It is mainly used for high temperature and high pressure transmission fluid header and pipeline on the boiler of the power station and Tianjin seamless steel tube nuclear power station. The representative materials are 20g, 12Cr1MoVG, 15CrMoG steel tube scaffold, etc.