Precautions for cold bending of Laoshan brand PVC electrical casing

The flame-retardant and insulated electrical bushings of Qingdao Laoshan Pipe Industry have strict cold bending requirements. When bending flame-retardant and insulated electrical bushings with an outer diameter of ≤25mm, the special spring for Laoshan Pipe Industry should be inserted into the tube according to the required length. And the angle is bent, among which the spring of the bending machine should pay attention to the following points:

  A. The spring used should not be twisted too severely and deformation is not allowed. Unqualified springs will twist and damage the tube and cause the spring to be stuck in the tube. The outer diameter of the spring should be less than the inner diameter of the tube 0.7-1mm. When bending a longer tube, One end of the spring should be tied with a rope in order to pull it out. It is best not to bend the pipe more than 90 degrees. For pipes of ∮20, the bending radius R＞50mm, for pipes of ∮25, the bending radius R＞62.5mm.

  B. Due to the rebound of the pipe, after the spring is inserted into the pipe, it should be bent slowly. The angle of the hand bend is slightly smaller than the required angle. In cold weather, the pipe should be held in the hand with a cloth and rubbed repeatedly at the bend to make It becomes hot, and then bend, if the bending speed is too fast. Easy to damage the pipe and spring.

  C. If surface installation is used during installation, the bent pipe should be fixed with pipe clamps. After the pipe is bent, when the spring is pulled out, it cannot be forcibly pulled out. The spring should be turned counterclockwise and pulled out slowly to prevent the spring from being stuck or damaged. If the bending angle of the pipe is not satisfactory, it is not possible to forcefully pull it to restore it, so as not to damage the spring and pipe fittings.