1. Grinding of the pipe mouth of seamless steel pipe: After cutting, the plastic layer of the pipe mouth should be polished with an angle grinder. The purpose is to avoid melting or burning of the plastic layer during flange welding and destroying the pipe. Use an angle grinder to polish the plast

6. GB9948-1988 (seamless steel pipe for petroleum cracking). Mainly used in boilers, heat exchangers and fluid pipelines of petroleum smelters. Its representative materials are 20, 12CrMo, 1Cr5Mo, 1Cr19Ni11Nb, etc.7. Steel pipes for geological drilling (YB235-70) are steel pipes used for core drilli