The seamless elbow, as the name suggests, corresponds to the straight line bend, which is a pipe that is used to bend the pipe, and it is also called seamless steel pipe bend. The seamless elbow fitting is divided into two kinds: hot rolling (extrusion) seamless elbow and cold drawing (rolling). Cold drawing tube is divided into two types: round tube and heteroid pipe.
A seamless elbow is a kind of pipe that is used for pipe turning。 The proportion of all pipe fittings used in piping system is large, about 80%。 In general, different forming processes are selected for the elbow of different materials。 At present。 The seamless elbow forming process used by the manufacturer is hot, pressing, extrusion, etc。
The raw material of the seamless elbow pipe is a round tube billet, which needs to be cut and processed by the cutting machine for about a meter of billet, and is sent to the furnace for heating. The billets are heated in a furnace and the temperature is about 1,200 degrees Celsius. Fuel is hydrogen or acetylene. Temperature control in the furnace is a key problem. After the round tube billet is out, it will be worn by the pressure perforator. Generally more common piercer is conical roller piercer, which has high production efficiency, good quality and perforation diameter, which can wear many kinds of fittings. After perforation, the round tube billet has been rolled, rolled or squeezed by three rolls. After extruding, take out the diameter of the pipe. The sizing machine is used to form the pipe fitting through the high speed of the taper drill.
Seamless elbow process:
1, cold drawing (rolling) seamless elbow pipe fittings, pipe billet and heating to punch to heading, annealing, pickling and oil (copper) and multichannel time cold drawing (cold rolled) to the tube billet - heat treatment - straightening, hydrostatic test (NDT) - > tag to put in storage.
2, hot-rolled seamless elbow pipe fittings (extrusion) : the circular tube billet - heat - punch - three-roll skew rolling, rolling, or pressing - to take off the tube and sizing (or reducing) - cooling - straightening to hydrostatic test or inspection - > tag, put in storage
Advantages of seamless elbow:
1. The chemical components of the product are unchanged, grain is refined and the metallographic organization meets the requirements. Geometry size and roundness error, Angle error and the amount of thinning can implement strict control, the internal and external surface is smooth, bright and clean, beautiful, no oxidation and decarburization, wrinkling, double skin, such as crack defects. Good mechanical performance, ensure safe use.
2. It is possible to realize the joint of push and arbitrary number, which can not be achieved by other elbow making techniques.
3. Seamless elbow technology is produced under the conditions of high technical process equipment and mechanized automation. Therefore, product quality stability, high production efficiency and low labor intensity.