Seamless elbow: elbow pipe fittings for a turn at. All fittings in piping systems in use, the largest proportion, about 80%. Typically, the wall thickness of different materials or to select a different bend forming process. Currently, the factory used the hot forming process seamless elbow pushing, pressing, extrusion. a. Hot push push elbow forming hot forming process is the use of special elbow pushing machine, the mandrel and the heating device, so that the mold set in the blank under the impetus pushing machine forward movement, is heated in motion expanding and bending forming. Hot push elbow tube diameter deformation characteristics are determined in accordance with the law of constant volume before and after plastic deformation of metallic materials, used in the elbow tube diameter less than the diameter of the mandrel through controlled deformation of the blank, the inner arc of the compressed metal flow, to other parts of the compensation due to the enlarged diameter and thinned, thereby obtaining a uniform wall thickness of the elbow. Hot push elbow forming process has a beautiful appearance, uniform thickness and continuous operation, suitable for mass production characteristics, and thus become carbon steel, alloy steel, the main method of forming the elbow, and is also used in certain types of stainless steel elbow The forming. Forming process heating intermediate frequency or high frequency induction heating (heating coil for multiple laps or lap), flame heating furnace heating and reflection, depending on what kind of heating energy requirements and shaping the product of decisions b. Stamping stamping elbow was first used in mass forming process seamless elbow, at present, in the production of common specifications elbow has been replaced by extrapolation or other hot forming process, but in some specifications of the elbow due to the number of production less wall thickness is too thick or too thin. When the product is still in use with special requirements. Elbow bend press forming using the outer diameter and equal to the tube, using the direct compression in a mold press forming. Before stamping, tube placed on the lower die, the inner core and the end of the tube into the mold, the mold pressing downward movement started by the constraints and support role within the mold so that the outer mold forming elbow. Compared with hot push technology, visual quality is better than the former stamping; stamping elbow when forming outside the arc in tension, no other parts of the excess metal to compensate, so the thickness of the outer arc of about 10% to about thinning . However, as for single-piece production and low cost, it is used for stamping elbow craft small batch manufacturing thick elbow. Steel, alloy steel, stainless steel, copper, aluminum, plastic, argon Ge Lek, PVC, PPR, RFPP (reinforced polypropylene). 2. production methods can be divided into push the system, pressing, forging, casting and so on. 3. manufacturing standards can be divided into GB, electricity standard, ship standard, technology standard, water standard, American standard