The carbon steel elbow is bent and shaped by a hot push elbow machine in the factory.
The main process of the hot push elbow machine is equipped with an intermediate frequency heating coil,
a propulsion device, a chuck, a cooling device, a rocker arm, a gearbox, and a control panel and transformers etc.
Its working principle is to use the intermediate frequency heating coil to heat the steel pipe,
and at the same time push the propulsion device forward, the rocker arm pulls the steel pipe to rotate,
and the cooling device uses water cooling or air cooling to reduce the temperature of the steel pipe,
so that the heat pushes the elbow stereotyped. This processing method mainly controls the quality by adjusting the heating temperature,
advancing speed and cooling speed of the hot pushing elbow machine. Compared with cold-bending elbows, hot-push elbows have the following advantages.
(1) The quality of the hot push elbow is better, the roundness of the mouth, the overall flatness and the bending angle are better,
the inner side of the bending section is smooth, especially there are no wavy folds in the bending section.
(2) There is a straight pipe section with a length of nearly 660mm in the hot push elbow, which is conducive to beveling, connection.
(3) After the hot push elbow has passed the appearance inspection and radiographic flaw detection inspection, heat treatment is
also carried out to ensure that the mechanical performance of the elbow is consistent with the design value.
(4) The strength of the straight pipe selected by the national standard elbow is usually 50-70MPa
higher than the design required elbow, which effectively avoids the influence of the Bauschinger effect.
(5) The wall thickness of the straight pipe used in the carbon steel seamless elbow is greater than the designed wall thickness of the elbow, so that the thinning rate of
the elbow production is controlled below the specified value of 10% (usually controlled below 8%), ensuring that the elbow The quality of the head meets the design requirements.
(6) The hot push elbow has strong adaptability, the elbow angle is large, and the hot push bend can be arbitrarily made in the range of 0-90 °.
Post time: Jun-05-2023