Therefore the selected radius of the elbow can be very important. The other type of elbows is reducing elbows. In this type of elbows, the dimension of the center-line radius equals to the half of the nominal size of the larger end. Reducing elbows, again, maintain a 90¡ã flow change in the pipeline system. Moreover, a 180¡ãflow change can also be maintained by using a specific type of reducing elbow that is called ¡®return bends.