Analysis of main causes causing quality decline of elbow and precautions

　　The position of the neutral axis is different from that of the pipe elbow method. When the top bending (compression bending) works, the neutral axis is about 1 / 3 away from the outer wall, and when the rotary pipe elbow (back bending) works, the neutral axis is 2 / 3 away from the outer wall. Therefore, it is beneficial to use the rotary bending method for the pipe elbow of thin-walled pipes.

　　The accuracy of pipe elbow tire is also one of the factors affecting the quality of pipe elbow. During the manufacture of bent tire, in addition to the specification and size requirements controlled within a certain tolerance range, users are also required to corresponding bent tire according to the bent pipe diameter.

　　The bendability and surface corrosion of the pipe itself may also affect the quality of the elbow. During on-site construction, the operator also needs to understand the material and processing performance of the processed pipeline and make production judgment on the surface corrosion.