The bending pipe is bent with a complete set of bending equipment, which can be divided into two kinds of technology. No matter which kind of machine equipment and pipeline, most use bend pipe, mainly used for oil, gas, infusion, engineering bridge construction and so on.
Analysis and attention to the main causes of the quality degradation of bending pipes:
1。 When pure bending, the external force of the tube is applied to the outer arm of the sexual layer and the lateral arm wall is reduced by tensile stress & 1。 The effect is thickened and the force N1 and N2 make the cross section of the tube change。 Based on this factor, causes the decrease of the quality of the bent pipe main reason for the RX and SX so GBJ235-82, RX value of under various pressure levels and thinning of the lateral mass were made specific provision, the purpose is to control the value of RX and SX, to ensure the quality。
2, has spoken of the preceding article, bend the material of the lateral tensile, compression of the inside of the neutral axis location is different and pipe bending method, when he worked in top bending type (compression bending) neutral axis in about 1/3 from the outer wall, the rotating bending (bend), neutral axis in two-thirds from the outer wall。 Therefore, the thin-wall duct is bent, and it is beneficial to use the bending method。
3。 The precision of bending tire is also one of the factors that influence the quality of bend pipe。 When we manufacture the curved tyres, we also require the user to choose the corresponding curved tire according to the bending diameter when using。
4。 The bending performance and surface corrosion of the tubing itself may also affect the quality of the bending pipes。 During site construction, the operator also needs to understand the material of the treated piping, the processing performance and the production judgment of the surface corrosion。
5. Now provide R. (bending radius/outer diameter) relationship curve diagram for users to refer to the relationship between pipe diameter and wall thickness. The influence of relative bending radius and relative wall thickness on bending pipe quality is reflected in the acceptance specification of pipeline processing: the steel pipe with cold bending is the middle and low pressure is 4D and the high pressure is 5D. We bend tire design for R = 4 d (special another case may be), so in terms of my factory production of pipe bender mainly choose the relative wall thickness SX, the upper part of the figure is no core shaft area, central figure for the common core shaft, the lower part of the figure as a special core shaft section. Because of the difficulty in the design and manufacture of the special core shaft, the operation is not very convenient. Special circumstances may be agreed upon.