Large diameter carbon steel bend
The large diameter carbon steel elbow is made by the centrifugal method. Is inside the pipe die elbow on centrifuge, add red iron oxide and aluminum powder mixture inside the elbow, the mixture in a chemical called thermit, pipe die when the centrifuge rotation after reaching a certain velocity, lit by a Mars thermit, thermit immediately their burning, burning wave spread rapidly, as the spread of violent chemical reaction.
The large diameter carbon steel elbow is divided into the radius of curvature, which can be divided into long radius elbow and short radius elbow. The long radius elbow refers to its radius of curvature equal to 1.5 times the outer diameter of the pipe, namely R = 1.5d. The radius of curvature of the short radius is equal to the diameter of the tube, which is R = 1.0d. To bend diameter (D, R for the radius of curvature) in terms of classes, about seventeen, and American standard pipe is the same, there are: Sch5s, Sch10s, Sch10, Sch20, Sch30, Sch40s, STD, Sch40, Sch60, Sch80s, XS; Sch80, Sch100, Sch120, Sch140, Sch160, XXS, which are commonly used are STD and XS. According to bend Angle, has 45 ° elbow, and 180 ° 90 ° elbow bend.
Large diameter steel bend forming process is: first, a cross section welding for polygon or both ends closed multi multi ring shell fan shell, internal filled with medium pressure, with inner pressure and internal pressure under the action of cross section of polygonal gradually became round, and eventually become a circular ring shell. According to the need of a circular ring shell can be cut into four 90 ° bend or six 60 ° elbow or other specifications of the elbow, the process is suitable for manufacturing elbow pitch diameter and any specifications of large elbow bend diameter ratio greater than 1.5, is the ideal method of manufacturing the large pressure on the elbow. This process is suitable for the manufacturing work pressure less than 10MPa, the inner diameter of the elbow is d125mm, the diameter D of the elbow and the diameter D of the elbow is D/d1.5, and the size of the diameter of the elbow is not limited. For example, the diameter of the elbow is 12m, and the diameter of the elbow is more than 60m.
Advantages of large diameter carbon steel elbow:
1. No pipe is required for raw material, which can be used to save the cost of pipe and mould, and can get any elbow with a relatively thin wall thickness.
2. The blank is flat or developable surface, so the lower material is simple, the precision is easy to guarantee, the assembly welding is convenient.
3. Due to the above two reasons, the manufacturing cycle can be shortened and the production cost is greatly reduced. Because it does not require any special equipment, especially suitable for the site processing large elbow.