304 Stainless Steel 90 Degree Elbow Industrial Grade Stamping Welding Pressing Pickling Large Diameter Elbow Pipe

304 Stainless Steel Elbow Stair Handrail Elbow 90 Degrees Welded Industrial Elbow Sanitary Elbow Fittings

Seamless elbow: Elbow is a pipe fitting used at bends in pipes. In the pipeline system used in all pipe fittings, accounted for the largest proportion of about 80%. Usually, different forming processes are selected for elbows of different materials or wall thickness. Manufacturers commonly used seamless elbow forming process has hot push, stamping, extrusion and so on.
Push hot forming
Hot push elbow forming process is the use of special elbow push machine, core die and heating device, so that the billet set on the mold in the push of the machine to move forward, in the movement of heating, expanding and bending forming process. Hot push bend deformation characteristics are based on volume before and after plastic deformation rule of metal materials determine the pipe diameter, pipe diameter bend diameter, through the core module and control the deformation of the process, make the inner arc compressed metal flow, the compensation to other parts of the thinned by hole diameter, wall thickness uniform Angle is obtained.
Hot push elbow forming process has the characteristics of beautiful appearance, uniform wall thickness and continuous operation, suitable for mass production, so it has become the main forming method of carbon steel, alloy steel elbow, and also used in the forming of some specifications of stainless steel elbow.
The heating method of forming process has medium frequency or high frequency induction heating (heating ring can be multiple or single ring), flame heating and reflector heating, which heating method depends on the requirements of forming products and energy conditions.
stamping
Stamping elbow is the earliest forming technology used in mass production of seamless elbow. It has been replaced by hot push method or other forming technology in the production of common specifications of elbow. However, in some specifications of elbow, the production quantity is small, the wall thickness is too thick or too thin.
The product is still in use when it has special requirements. Elbow stamping is formed by using the tube blank equal to the outer diameter of the elbow, which is directly pressed by the press in the mold.
Before stamping, the tube blank is placed on the lower die, and the inner core and end die are loaded into the tube blank. The upper die moves down and begins to press, and the elbow is formed by the constraint of the outer die and the support of the inner die.
Compared with the hot push process, the appearance quality of stamping is inferior to the former. When the stamping elbow is formed, the outer arc is in a stretch state, and there is no excess metal compensation in other parts, so the wall thickness at the outer arc is reduced about 10%. However, due to the characteristics of being suitable for single piece production and low cost, stamping elbow technology is mostly used in the manufacture of small batch and thick wall elbow.
Stamping elbow is divided into cold stamping and hot stamping, usually according to the material properties and equipment capacity of the choice of cold stamping or hot stamping.
The forming process of cold extrusion elbow is to use a special elbow forming machine, put the tube blank into the outer mold, after the upper and lower mold, under the push rod, the tube blank along the inner mold and the outer mold reserved clearance movement and complete the forming process.
Using internal and external die cold extrusion process manufacturing elbow beautiful appearance, uniform wall thickness, small size deviation, so for stainless steel elbow, especially thin-walled stainless steel elbow forming more use this process manufacturing. The internal and external mold used in this process requires high precision; The requirement of wall thickness deviation is also very strict.
Medium plate welded
Use the middle plate to make one half of the elbow section with a press and then weld the two sections together. This process is generally used to make elbow more than DN700.
Other forming methods
In addition to the three commonly used forming processes, seamless elbow forming also uses the tube blank extrusion to the outer die, and then through the tube blank ball shaping forming process. However, this process is relatively complex, difficult to operate, and the forming quality is not as good as the foregoing process, so it is seldom used