1. In a piping system, an elbow is a fitting that changes the direction of a pipe run.
 2. According to the angle, there are three most commonly used types: 45 ° and 90 ° 180 °. In addition, 60 ° and other abnormal angle elbows are also included according to the project needs.
 3. Elbow materials include cast iron, stainless steel, alloy steel, malleable cast iron, carbon steel, nonferrous metals and plastics.
 4. The connection methods with pipes include: direct welding (the most commonly used method) flange connection, hot melt connection, electrofusion connection, threaded connection and socket connection.
 5. According to the production process, it can be divided into: welding elbow, stamping elbow, pushing elbow, casting elbow, butt welding elbow, etc.
 6. Other names: 90 degree bend, right angle bend, etc.