Most packing sets have five packing rings. The lantern ring can be inserted after the second or third packing ring is installed. This all depends on where the flush port of the stuffing box is located. To ensure that the lantern ring is installed correctly, insert a small object through the flush port and feel the lantern ring. Once this is done and all the packing rings and packing follower are installed, end users should install the proper flush setup and start flushing the stuffing box. For many reasons, starting the flush before operating the pump is important. One reason is to ensure that flush water is moving through the lantern ring and into the stuffing box correctly. Care must be taken to ensure the lantern ring’s fit around the shaft is correct. Most lantern rings have a larger fit on the inside diameter and a tighter fit on the outside diameter, so frictional heat is not an issue.