Seamless elbows: Elbows are pipe fittings used at pipe bends. They account for the largest proportion of all pipe fittings used in piping systems, approximately 80%. Different forming processes are typically selected for elbows made of different materials or with different wall thicknesses. Commonly used seamless elbow forming processes by manufacturers include hot pushing, stamping, and extrusion.
The hot pushing elbow forming process uses a specialized elbow pushing machine, mandrel, and heating device. The blank, placed on the mandrel, is pushed forward by the pushing machine, where it is heated, expanded in diameter, and bent into shape. The deformation characteristics of hot pushing elbows are determined based on the principle that the volume of the blank remains unchanged before and after plastic deformation of the metal material. The diameter of the blank used is smaller than the elbow diameter. The deformation process of the blank is controlled by the mandrel, allowing the compressed metal at the inner arc to flow and compensate for the thinning of other parts due to diameter expansion, thus obtaining an elbow with uniform wall thickness.
Hot-push elbow forming process has the characteristics of beautiful appearance, uniform wall thickness and continuous operation, which is suitable for mass production. Therefore, it has become the main forming method for carbon steel and alloy steel elbows, and is also used in the forming of certain specifications of stainless steel elbows.
