Pipe bend is produced step by step, and then made into finished products, in the whole production process, because of the requirements of the pipe must be bent, and the bending of the pipe to have some technology, the degree of bending is not the same, so in the whole production process used in the technical requirements?

• 1. The online heat treatment of the weld of the closed section can offset the welding stress of the elbow, improve the weld structure, and anneal or normalize the whole cold-formed steel to offset the stress. The mechanical properties of cold-formed steel include strength, tensile strength and elongation after breaking.
• 2. Surface of bend must not have bubbles, cracks, scars, fold, inclusions and hierarchical, allow a slight pit is not more than 10% of the nominal thickness, convex, indentation, hairline, scratches and pressure into the iron scale, surface defects should use grinding method to clean up, but clean up after cold bending steel thickness shall not be less than allowed.
• 3. The pipe bend is bent by complete set of bending equipment, which is divided into two processes: cold simmer and hot push. No matter what kind of machinery, equipment, pipeline, most of the pipe bend, mainly used for oil, gas, infusion, engineering bridge construction, etc..
  

As a result, the technology is used in the production of the bend, with the increase of bend and pipe requirements, the use of the pipeline technology will be more and more advanced, in the process of bending the burr should be clear in time the line pipe bending quality is a lot of people focus on one aspect, decided the post processing and construction quality, so in the process of production, the quality is really important.

What are the factors that affect the quality of the bend?

• 1. The precision of bending tire is one of the factors affecting the quality of pipe bend. In the manufacturing process of bending tire, in addition to the limitation of specifications and sizes, the bending process also requires users to select the corresponding bending tire according to the diameter of pipe bend.
• 2. For the user to choose pipe diameter and wall thickness of the relationship as a reference, according to the acceptance standard pipe processing, reflect the relative bending radius and relative wall thickness on the quality of the pipeline, pure bending, under the effect of external force, the neutral layer outside the arm wall thinning of the tensile stress, the inside of the compressive stress, effect and thickening, together make the pipe cross section change.
• 3. The bending function and appearance erosion of the pipe itself will also affect the quality of the elbow. Observe the processing function and surface corrosion.
• 4. In the process of traditional pipe bend production, the enterprise will take many measures to obtain good bend surface quality, including using more advanced, more high-grade pipe bender, using a higher intensity of mould, or use a lubricant products, use high-grade pipe bender and high strength die, companies often need to spend a lot of money to complete, Only the use of pipe bender lubrication products can cheaply and quickly meet the requirements of enterprise product quality, but in the traditional production process, oil based pipe bend lubrication products can meet the enterprise in the production of pipe bend quality requirements, but the oil based pipe bend lubrication products are very difficult to clean and environmental pollution is very prominent. Therefore, enterprises must take more measures to eliminate the use of oil-base elbow lubrication products on the final product quality, and to invest more energy and money.
• 5. The bending performance and surface corrosion of the pipe itself may also affect the quality of the pipe bend. During field construction, the operator also needs to know the material of the pipe to be machined, machinability and make production judgment on the surface corrosion.

The quality of the bend is easily affected by the above factors, especially in the production process. When the pipe is produced and bent, we should pay attention to it. After all, many factors may affect the quality of the pipe.