JS FITTINGS

Q
How do the ASME B 16.9 60 inch pipe elbows be made?
A
How do the ASME B 16.9  60 inch pipe elbows be made?
Methods of produce steel pipe elbows

Steel pipe elbow is a kind of pipe fittings used for pipe turning, there are 90 degree elbows, 45 degree elbows and so on. It can be produced according to the engineering needs. Because of the different materials and different pressures, the manufacture process of pipe elbow is also different. So far, steel pipe elbow manufacturers commonly use 4 methods to produce seamless pipe elbows: hot-pushing, stamping,  extrusion and butt Welding.

Hot- pushed Pipe Elbows
The hot-pushing is a process used to produce seamless pipe elbows, using a elbow-push machine, a core mold and a heating device, the blank sheathed in the mold is pushed to run forward under the elbow-push machine. It’s a process of heating, expanding, diameter, and bending. The deformation characteristics of the hot-pushing elbows are determined according to the law of the metal material remains unchanged before and after plastic deformation. The diameter of the pipe blank is determined when the pipe is adopted. The diameter of the pipe is smaller than the elbow, to thinning out the rest of the body by expanding the diameter. Then the thickness of pipe elbow is uniform. The pipe elbows made by pushing machine have beautiful appearance and uniform wall thickness. The pushing machine is suitable for mass producing. So the main production process of general Carbon steel elbows and alloy steel elbows is hot-pushing which also used in certain specifications of stainless steel elbows forming.
Stamped Pipe Elbows

The stamping pipe elbow manufacturing process is the earliest application of the mass production of seamless elbow molding process which have been replaced by hot-pushing in common use. However, when the pipe elbow quality is small, some specifications and wall thickness is too thin or too thick , and with other special request, the factory will choose the stamping process. In the forming process, the diameter of blank pipe should be same with the finished pipe elbow, and be stamped into the forming of pipe elbows. Stamping process is divided into cold stamping and hot stamping, we select the manufacturing process according to the material. The stamping process is not as good as hot-pushing, especially the quality and appearance. In the forming process, the elbow outer-arc is in tension. There is no extra material to compensate the outer-arc, so the wall thickness at the outer-arc is about 10% thinner than before. However, due to the characteristics of unit production and low cost, the stamping process is suitable for small batch production of high-pressure thick-wall elbows.

Previous:Differences between seamless elbows and welded elbows

Next:Differences between steel pipe bends and pipe elbows