Firstly, the customer needs to clarify the specifications and models of the elbows they need to purchase, that is, the diameter of the elbow, They should consider whether to choose equal elbow or reducing elbow, as well as confirm the standards, pressure levels, or wall thickness of the elbows. Secondly, the material of the elbows should be considered. Secondly, the issue of corrosion prevention should be addressed, and whether the elbows need to be painted or sandblasted.
1. Why pay attention to the material of the elbow?
For different purposes, it is necessary to use corresponding elbows of different materials to match. Common materials can be divided into stainless steel elbows and carbon steel elbows. The chemical composition contained in stainless steel elbows will prevent the surface of the elbow from rusting and corrosion for a long time. The main reason for its difference from carbon steel elbows is the difference in material.
A stainless steel elbow is formed by stamping a circular shape from a sheet of the same material, connecting the two halves together and then welding them together. After being pushed in, it is further reshaped under heating to ensure that the outer diameter and wall thickness of the elbow meet the requirements. Then, shot peening is carried out to remove the oxide skin on the inner elbow fitting and the outer surface of the bending head, with both ends tilted for easy welding.
2. Why pay attention to the size of the elbow?
A typical elbow is one and a half times the size, represented by R=1.5D. However, throughout the pipe fitting market, most production molds are 1.25D, which is the 0.25D gap. The raw materials used for pushing elbows, that is, pipes, may save a lot, resulting in a significant weight difference and price difference. This is known as non-standard elbows, which are much shorter than standard elbows. Inappropriate models of elbows can also cause mismatch issues during use, leading to equipment incompatibility.
3. Why do we need to determine if anti-corrosion elbows are needed?
Anticorrosive elbow refers to an elbow that has been processed and treated with anti-corrosion technology, which can effectively prevent or slow down the occurrence of chemical reactions during transportation and use, leading to the corrosion of the elbow. Common methods include using non-toxic and odorless anti-corrosion coatings for treatment, and applying epoxy powder on the surface of elbows using electrostatic spraying. Anticorrosive elbows are not only corrosion-resistant, but also resistant to bending, high temperature, impact, fast drying, alkali resistance, good adhesion, acid resistance, salt resistance, and good softness. They are suitable for various fields such as natural gas, sewage treatment, petroleum, and tap water. Anticorrosive elbows are generally used in some special occasions.
4. Why pay attention to the wall thickness of elbows?
Taking the elbow in natural gas production and operation as an example, the elbow of natural gas gathering and transportation pipeline is prone to rapid thinning under the synergistic erosion of corrosion and erosion, which affects the safety of pipeline operation. Therefore, it is necessary to measure the wall thickness at the elbow of the pipeline. The application of ultrasonic thickness measurement technology in the wall thickness sampling inspection of the elbow part of natural gas gathering and transportation pipeline network is utilized.
Post time: Apr-27-2023
