in the pipe system,  elbow is a piece of pipe that changes the direction of the pipe.

Commonly there are three Kinds of angles 45V, 90V and 180V, 60V, 135V and other non-standard product are Also needed in engineering application. 

the material of elbow Has cast iron, stainless steel, alloy steel, copper, malleable cast iron, carbon Steel, nonferrous metal and plastic etc. Connection types with pipe: direct Welding (the most common way), flange connection, hot melt connection, electric Melting connection, thread connection and socket connection. According to the Production process can be divided into: welding elbow, stamping elbow, pushing Elbow, casting elbow etc.