Seamless elbow is a kind of pipe used to rotate pipes. Of all the fittings used in the pipeline system, the proportion is the largest, about 80%. Usually, different forming processes are selected for elbows with different wall thickness. At present. The common forming processes of seamless elbows in manufacturing factories include hot pushing, stamping, extrusion and so on.


The raw material of seamless elbow fittings is round tube billet. The tube embryo is cut by cutting machine to grow about 1 meter billet, which is sent to furnace to be heated by conveyor belt. The billet is fed into the furnace and heated to about 1200 degrees Celsius. Fuel is hydrogen or acetylene. Furnace temperature control is a key problem. After the round billet is released, it is subjected to through-hole punching machine. A more common punch is a tapered roller punch. The perforator has high production efficiency, good product quality, large perforation diameter and can pierce various pipe fittings. After piercing, the round billet is rolled or extruded continuously by three rolls. After extrusion, the pipe should be sizing. The shaping machine is rotated to the steel core at high speed through a conical bit to form a pipe.


Forming method of seamless elbow
1. Forging method: stamping one end or part of the pipe with a die forging machine to reduce the outer diameter. The common forging machine has rotary, connecting rod and roll shapes.
2. Rolling method: generally not using the mandrel, suitable for the inner edge of thick-walled pipe. The core is placed in the tube and the peripheral is pressed by the roll for rounding.
3. Stamping method: The pipe end is extended to the required size and shape, and the conical core is on the press.
4. Bending forming method: There are three commonly used methods, one is called stretching method, the other is called pressing method. The third method is roller method. There are 3-4 rollers, two fixed rollers, one adjusting roller, adjusting the use of fixed rolling clearance. The finished pipe is bent.
5. Inflatable method: one is to place rubber in the tube, compress the upper part with punch to make the tube bulge; the other is to form hydraulic bulge, fill the middle of the tube with liquid, and the liquid pressure will bulge the tube into most required shapes and bellows production in this way.