Elbow in the pipeline system, elbow is a pipe fittings to change the direction of the pipeline. According to the angle, 45 degrees and 90 degrees 180 degrees are the most commonly used, and other abnormal angle elbows such as 60 degrees are included according to the engineering requirements. Elbows are made of cast iron, stainless steel, alloy steel, malleable iron, carbon steel, non-ferrous metals and plastics. The ways to connect with pipes are: direct welding (the most commonly used way) flange connection, hot melt connection, electric melt connection, threaded connection and socket connection. According to the production process, it can be divided into welding elbow, punching elbow, pushing elbow, casting elbow, butt welding elbow and so on. Other names: 90 degree elbow, right angle bend, love and bend, etc.
A kind of pipe fittings commonly used in pipeline installation is to connect two pipes with the same or different nominal diameter to make the pipeline turn at a certain angle with nominal pressure of 1-1.6 Mpa.