The Category and Forming Process of Stamping Elbow

The Category and Forming Process of Stamping Elbow

The class of stamping elbows
Stamping elbow classify into cold stamping and hot stamping, we often choose cold or stamping based on the materials' properties and equipment capacity. The forming process of Cold extruding elbow--using dedicated elbow forming machine, put the billet into the external mold, after the top and bottom moulds combine, the billet formed with the push of pushrod. The pipe elbow which is made by inner and outer moulds cold extruding manufacturing technic is in a good shape, has an uniform wall thickness and a small size difference, so we usually use this kind of manufacturing technology for stainless steel elbow especially the stainless steel elbow with a thin wall thickness. The technique requires high accuracy for the inner and outer moulds and less deviation for the wall thickness of the billet.

The forming process of elbows
Stamping elbows are the earliest forming technology that are used in the batch manufacturing of seamless elbows, which is replaced by hot push or other forming technics. But in the manufacturing of elbows with other irregular sizes will still use the stamping method because of small quantity, very thick or thin wall thicknesses. The forming of stamping elbows uses the billet which has the same outer diameter as the elbows, and then use the press machine to press the mold. Before stamping, the billet should be put on the bottom mold, put the inner core and end mold into the billet, then the upper mould will move downward to press, elbows are formed by the constraint of outer mold and the support of inner mold.
Compared to the stamping process, the appearance of hot push technology is not as good as the stamping way. When the elbow is formed, the outer arc in a tensile state, there is no any extra metals from other parts to fill it up, so the wall thickness of the outer arc will reduce by 10%. The technology of stamping are always used in small batch elbows with thick wall thicknesses because of its features of single production and low cost.
 

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