The 90° elbow is used for grooved pipe connections, for connecting pipe corners and changing the direction of the pipe. Connect two pipes with the same nominal diameter to make a 90° turn in the pipes.

The 11.25°elbow is used for groove pipeline connection, which is mainly in pipeline bends to change the direction of the pipeline. It connects two pipes of the same nominal diameter to turn 11.25 degree. 

The 22.5°elbow is used for groove pipeline connection, which is mainly in pipeline bends to change the direction of the pipeline. It connects two pipes of the same nominal diameter to turn 22.5 degree.

The 45°elbow is used for groove pipeline connection, which is mainly in pipeline bends to change the direction of the pipeline. It connects two pipes of the same nominal diameter to turn 45 degree.