① Die forging
For socket welding and threaded tees, crosses, elbows and other small-sized pipe fittings, the shape is relatively complicated, and the die forging process should be used.
The billet used for die forging should be rolled profiles, such as bars, thick-walled pipes or plates. When steel ingots are used as raw materials, the steel ingots should be rolled into bars in advance or used as die forging billets after forging to eliminate defects such as segregation and porosity in the steel ingots.
After being heated, the blank is put into the die for forging (depending on the situation, it may be forged after the initial forging), the pressure makes the metal flow and fills the cavity; Steps to remove the remaining material from the flash, thereby completing all the forging work.
② Free forging
For special-shaped pipe fittings or pipe fittings that are not suitable for die forging, they can be manufactured by free forging process. Free forging should forge the general shape of the pipe fitting; such as a tee, the branch pipe should be forged.
③ Cutting
For some cylindrical pipe fittings, rods or thick-walled pipes can be directly cut into shapes, such as double socket pipe collars, unions, etc. The fiber flow direction of the metal material during processing should be roughly parallel to the axial direction of the pipe. For tees, crosses, elbows and pipe fittings, bar materials shall not be directly cut and formed.
