In piping systems, an elbow is a fitting that changes the direction of a pipe. According to the angle, there are three commonly used ones: 45°, 90° and 180°. In addition, according to the needs of the project, there are other special-shaped angle elbows such as 60°. Elbows are made of cast iron, stainless steel, alloy steel, malleable cast iron, carbon steel, non-ferrous metals and plastics.
The ways to connect with the pipeline are: direct welding (common way) flange connection, hot melt connection, electrofusion connection, threaded connection and socket connection, etc. According to the production process, it can be divided into: welding elbow, stamping elbow, pushing elbow, casting elbow, butt welding elbow, etc.
Elbow is a kind of connecting pipe commonly used in plumbing installation. It is used to connect the bend of the pipe and change the direction of the pipe.
Other Names: 90° Elbow, Right Angle Elbow, Stamping Elbow, Press Elbow, Machine Elbow, Welding Elbow, etc.
Uses: Connect two pipes with the same or different nominal diameters, so that the pipes can be turned at 90, 45, 180 and various angles.
Those with a bending radius less than or equal to 1.5 times the pipe diameter belong to elbows, and those with a bending radius greater than 1.5 times the pipe diameter belong to elbows.
Technical requirements for elbows
Since most of the pipe fittings are used for welding, in order to improve the welding quality, the ends are processed into grooves, leaving a certain angle and a certain edge. This requirement is also relatively strict, specifying the thickness, angle, and deviation range of the edge. Surface and mechanical properties are basically the same as pipes. For ease of welding, the steel grades of the fittings and connecting pipes are the same.
2, that is, all pipe fittings should be surface-treated, and the oxide skin on the inner and outer surfaces should be sprayed off by shot peening, and then painted with anti-rust paint. This is for the needs of export, and besides, it is also for the convenience of transportation in China, to prevent corrosion and oxidation, so we should do this work.
3. It is a requirement for packaging. For small pipe fittings, such as exports, it is necessary to make wooden boxes, about 1 cubic meter. It is stipulated that the number of elbows in such boxes cannot exceed one ton. This standard allows sets, that is, large sets and small sets, but the total weight generally does not exceed one ton. For large items, it needs to be packaged separately. For items such as 24", it needs to be packaged separately. In addition, the packaging mark should indicate the size, steel grade, batch number, manufacturer's trademark, etc.

Manufacturing standards: ASMEB16.9, GB/T 12459, GB/T 13401, SH3408, SY/T0609, SY/T0510, JIS B2311, JIS B2312, etc.

Materials: stainless steel 304, 304L, 304H, 321, 316, 316L, etc.
　　　Carbon steel Q235B, 20, Q245R, Q345R, Q355, etc.
　　　Alloy steel 15CrMoG, 12CrMoVG, 15CrMo, etc.
　　　Duplex stainless steel 2205, 2507
　　　Nickel base alloy, NO6600, NO4400, NO8800, etc.

Sizes: seamless from 1/2”-28” (DN15-DN700); seamed from 1/2”-140” (DN15-DN3200) 

Wall thickness: SCH5S-SHC160

Raw materials: seamless pipe, welded pipe, plate welding and forging (for high pressure)

Manufacturing process: extrusion, pressing, cold working, machining, welding and heat treatment

Surface treatment: sand blasting and acid pickling and passivation;

In addition, the product can be customized and processed according to customer drawings.