The 90° double-socket bend is bent by using a complete set of bending equipment, which is divided into two processes: cold simmer and hot push. No matter what kind of machinery, equipment and pipelines are used, most of them use double-socket bends of 90°, which are mainly used for oil, gas, infusion, engineering and bridge construction, etc.
The deformation degree of pipes depends on the value of relative bending radius R/D and relative thickness t/D. The smaller the value of R/D and t/D, the greater the deformation degree. In order to ensure the forming quality of pipe fittings, the deformation degree shall be controlled within the allowable range. The bending forming of pipe fittings depends not only on the mechanical properties and bending methods of materials, but also on the use requirements of pipe fittings. The forming of pipe fittings shall include the following contents:
(1) The elongation deformation in the tensile deformation zone outside the neutral layer does not exceed the plastic allowable value of the material, resulting in cracking;
(2) In the compression deformation zone of the inner side of the neutral layer, the thin-walled structure under the action of tangential compressive stress will not wrinkle beyond the buckling;
(3) If the pipe fittings have ovality requirements, control the distortion of its section;
(4) If the pipe fittings have the strength requirement to bear the internal pressure, the forming of the wall thickness reduction shall be controlled.
