Socket welding flange refers to a flange that is inserted into the flange ring ladder at the end of the pipe and welded on the outside of the pipe. There are two types: with neck and without neck. The flange with neck tube has good rigidity, small welding deformation, and good sealing performance, and can be used in situations with pressure ranging from 1.0 to 10.0 MPa. Type B flanges for containers are also socket welding flanges, used in situations where sealing requirements are high. During design, socket welding flanges can be verified as integral flanges.