Carbon steel elbow is divided according to its radius of curvature, which can be divided into long radius elbow and short radius elbow. Long radius elbow refers to its radius of curvature is equal to 1.5 times the diameter of the tube, that is, R = 1.5D. Short radius elbow means that the radius of curvature is equal to the outer diameter of the pipe, that is, R = 1.0D. (D is the diameter of the elbow, R is the radius of curvature) if divided by the pressure rating to about 17 species, and American Standard pipe is the same: sch5s, sch10s, sch10, sch20, sch30, sch40s, STD, sch40, sch60, sch80s, XS; sch80, sch100, sch120, sch140, sch160, XXS, which is the most commonly used is two kinds of STD and XS.
According to the angle of the elbow, 45 degree elbow, 90 degree elbow and 180. Carbon steel elbow of the basic process is: first welding a cross-sectional polygon polygon ring shell or closed at both ends of the multiple edges of fan-shaped shells, interior flushes the full pressure medium, subjected to internal pressure, internal pressure under the effect of cross section by the polygon gradually became round, eventually becoming a circular ring shells. According to the need, a circular ring shells can be cut into four 90 101 elbow or six 60 101 elbow or other specifications of the elbow and the technology application in manufacturing bend diameter and bend diameter ratio greater than 1.5 any specification of large elbow, is currently making the ideal method for the large carbon steel elbow.
The advantages of the carbon steel elbow making process are mainly shown in the following aspects:
(1) the pipe blank can be used as raw material, and the cost of the equipment and the die can be saved, and the carbon steel elbow with a relatively thin wall thickness can be obtained.
(2) the blank is a flat plate or a curved surface, so the blanking is simple, the precision is easy to guarantee, and the assembling and welding are convenient.
(3) due to the above two reasons, the manufacturing cycle can be shortened, and the production cost is greatly reduced. Because no special equipment is needed, especially suitable for the field processing of large carbon steel elbow.
Source: Zhejiang Yaang Pipe Industry Co., Limited (www.yaang.com)