PTFE Lantern rings， also well know by Universal Seal Cage are usually in the center of every compression packing set in a centrifugal pump. They are simple components, but get something wrong when selecting, installing or operating them, and big problems may occur in the stuffing box. A lantern ring is placed between packing rings in each packing set and extends the life of the packing, stuffing box and shaft. Ultimately, lantern rings increase the life span of the pump system.