What’s The Difference Between Pipe Bend And Steel Elbow
Dec 04, 2023
Steel Elbow Supplier-GNEE
What's The Difference Between Pipe Bend And Steel Elbow?
Steel elbows and steel bends are very common pipe fittings used to change the direction of flow in piping systems. In addition to pipe fittings used for connection, elbows also refer to a processing method. It bends straight pipes through processing methods to achieve the purpose of changing the flow direction of the pipes. The manufacturing process and finished product are called pipe bends.
In order to ensure that the wall thickness of the bent pipe part is not less than the wall thickness of the straight pipe part, the minimum radius of the bent pipe should be 3D (D is the nominal diameter of the bent pipe). Specific dimensions depend on operating conditions. In other words, there is no limit as long as the radius exceeds 3D. It can be 3D, 3.2D, or even 4D, 5D, 6D, or 8D. In addition, the bending angle can be any angle, and sometimes there are custom-designed bends, such as 22.5°, 45°, 90°, 135°, 180°, 270°, etc.
Pipe elbow is a commonly used pipe fitting in pipeline installation. It connects two pipes with the same or different nominal diameters and bends the steel pipe at a certain angle. Standard elbows only have short radius elbows (R=1.0D) and long radius elbows (R=1.5D). The maximum diameter of seamless elbows can generally reach 40" (Φ1020), which is between DN15-DN1000. Large-diameter pipes generally use butt welding elbows, with specifications between DN500-DN2500.
Both elbows and elbows can be seamless and welded. Generally, small and medium sizes are seamless, and large sizes are welded, such as spiral welding. Visually they are the same. Sometimes they are interchangeable, but not the same.
So what is the difference between elbows and steel elbows?
1. Industry specifications are different.
There are industry standards for pipe elbows, which have restrictions on size, materials, testing, bend radius and angle. Elbows are non-standard fittings that are usually customized according to the needs of the pipeline. Special sizes require manufacturing and processing requirements, and some may be processed in the factory, so sometimes there will be problems with uneven thickness.
2. The manufacturing process is different.
Seamless pipe elbows are manufactured using hot pushing, cold pushing, hot pressing and other methods. Bends include medium frequency bends, hot push bends and CNC bends. When elbows are used for pressure-bearing purposes, carbon steel pipes and alloy steel pipes use hot pushing processes and stainless steel cold pushing processes. The most commonly used process for bending pipes is medium frequency pipe bending, which is directly bent by a pipe bending machine without anti-corrosion treatment. .
3. The radius of the elbow is larger than the elbow.
The radius of curvature of the bend is greater than twice the diameter. The radius of curvature of the elbow is generally between one and twice the diameter of the pipe. The radius of the elbow is the specified value. For example, the long radius of a 10-inch elbow is 381mm and the short radius is 254mm. However, as long as the pipe is long enough, 10-inch elbows can be used as long as R ≥ 3D. For example, 3D10"R is 762mm. As long as the actual working conditions permit, 800mm, 1000mm and 1005mm are all feasible.
4. The price of elbows is lower than that of elbows.
Due to different manufacturing methods, elbows are all customized and require anti-corrosion treatment, so the ordering cycle is long. Bends are made directly at the construction site, with lower transportation and time costs
5. The mechanical strength of the elbow is greater than the mechanical strength per unit area of the elbow.
Different radii and manufacturing processes result in differences in the strength of elbows and elbows. In practical applications, in order to prevent the fluid from scouring the curved section, thick-walled elbows or large-radius elbows can be used to reduce the scouring force.
