Views: 2 Author: Site Editor Publish Time: 2021-01-15 Origin: Site
Analysis of the main reasons for the decline in quality of elbows and methods of attention:
1. In pure bending, under the action of external force M, the outer arm wall of its neutral layer is thinned by tensile stress &1, and the inner side is under compressive stress. The resultant force N1 and N2 make the cross section of the tube change. Based on this factor, RX and SX are the main reasons that cause the quality of elbows to decrease. Therefore, in GBJ235-82, the RX value under various pressure levels and the amount of thinning on the outside are clearly specified, and the purpose is to control RX. And the value of SX, thus ensuring quality.
2. As mentioned in the previous article, when the pipe is bent, the outside of the material is stretched, and the position of the neutral axisunder pressure on the inside is different from the bending method. When the top bending (compression bending) works, the neutral axis is about 1/from the outer wall. At 3 locations, the neutral axis is located 2/3 away from the outer wall when working in a rotary bending (return bending). Therefore, when thin-walled pipes are bent, it is beneficial to use the twist bending method.
3. The accuracy of the bent tire is also one of the factors affecting the quality of the bent tube. When we manufacture bent tires, in addition to the specification and size requirements to be controlled within a certain tolerance range, we also require users to select the corresponding bent tires according to the bent pipe diameter during use.
4. The bendability and surface corrosion of the pipe itself may also affect the quality of the bend. During on-site construction, the operator also needs to understand the material, processing performance and surface corrosion of the pipeline to be processed.
5. R is now available. (Bending radius/tube outer diameter) relationship curve diagram for users to refer to when selecting the relationship between tube diameter and wall thickness.
Reflecting the influence of the relative bending radius and relative wall thickness on the quality of the elbow, according to the acceptance specification for pipe processing: cold-formed steel pipes are 4D for medium and low pressure and 5D for high pressure. Therefore, our bending tire design is R=4D (special circumstances to be determined separately), so for the tube bending machine produced by our factory, the relative wall thickness SX is mainly selected.
The upper part of the figure is the area without mandrel, and the middle part of the figure It is a common mandrel area, and the lower part of the figure is a special mandrel area. Since the design and manufacture of special mandrels are difficult and the operation is not very convenient, our factory generally does not supply them. Special circumstances can be negotiated separately.
6. The influence of lubrication on product quality during the molding process:
In the traditional pipe bending production process, enterprises will adopt many methods to obtain better surface quality of the pipe bending, including: using more advanced and high-grade pipe bending machines, using higher-strength molds, or using lubricating products, etc. Method. The use of high-end pipe benders and high-strength molds often requires companies to invest very large funds to complete it. Only the use of bent pipe lubrication products is relatively cheap and fast to meet the requirements of enterprise product quality.
But in the traditional production process: oil-based elbow lubrication products can meet the company’s elbow quality requirements in the production of elbows, but the difficulty of cleaning and environmental pollution of oil-based elbow lubrication products are very prominent. In this way, companies must use more methods to eliminate the impact of oil-based elbow lubrication products on the quality of the final product, and invest more energy and funds for this. The arrival of IRMCO elbow water-based grease not only meets the company’s requirements for the quality of elbow products, but also avoids and reduces the increase in investment due to the use of oil-based elbow lubrication products, and completely optimizes the production process of the company.
In the application process of traditional oil-based lubrication products, the production efficiency of enterprises is greatly restricted. Because of the fluidity and extremely difficult cleaning of oil-based lubrication products, it also causes pollution to the production environment and working conditions of workers. Such pollution often requires a lot of money and manpower and material resources. Adopting can reduce or even avoid the above-mentioned manpower and material resources for cleaning up pollution, and its feature of no-washing and direct welding can greatly improve the production efficiency and product quality of the enterprise. The amount of IRMCO water-based elbow grease can usually be reduced by 50%-80% compared to traditional lubricants, which can save more costs for enterprises.