For small size pipe fittings such as socket welding and threaded tees, tees, elbows, etc., their shapes are relatively complicated, and they should be manufactured by die forging.
The blanks used for die forging should be rolled profiles, such as bars, thick-walled tubes, or plates. When using steel ingots as raw materials, the steel ingots should be rolled into bars or forged and then used as blanks for die forging to eliminate defects such as segregation and looseness in the steel ingots.
The billet is heated and put into the die forging. The pressure makes the metal flow and fills the cavity. If the blank after dies forging has flash, it has to go through the step of flushing of the flash material to complete all the forging work.
Pipes with special shapes or those that are not suitable for die forging can be manufactured by the free forging process. For free forging, the general shape of the pipe fittings should be forged, such as the tee, the branch pipe parts should be forged.
Some tubular parts with a cylindrical shape can be directly formed by cutting rods or thick-walled tubes, such as double-socket tube hoops and unions. The fiber flow direction of the metal material should be roughly parallel to the axial direction of the pipe during processing. For tees, tees, elbows, and pipe fittings, it is not allowed to be directly formed by cutting bars.