Pushing elbows are push-forming elbows. The most important kind of elbow forming production process when elbows are push-forming The speed is fast, and the quality of the elbow is good. The forming process of the elbow is the most important forming process of the elbow. The basic process of forming technology of large push elbow elbow is: firstly weld a polygonal ring shell with polygonal cross section or polygonal fan shell with closed ends, when the inside is filled with pressure medium, apply internal pressure, Under the action of internal  pressure, the cross section gradually changes from a polygon to a circle, and finally becomes a circular annular shell. This is the process of forming large push elbow elbows.