The 90° pipe elbows is used to connect tubes at a 90° angle. As the name suggests, the elbow is always a right-angle in shape. Such type of elbow is also known as "90 bends or 90 ells". This is a pipe fitting device which is bent in such a way to produce 90° change in the direction of flow of the fluid/gas in the pipe. The elbow is used to change the direction in piping and is also sometimes called a "quarter bend".
A 90° elbow attaches readily to pipes of various materials like plastic, copper, cast iron, steel, lead, rubber etc. In other words, the 90° elbows are used to provide a joint between two pipes at right angles to each other. They are used as railing ends or corners on a level installation.