A _______ is a spacer installed between two of the rings of packing in a pump.

• A. Gland
• B. Packing ring
• C. Quill ring
• D. Lantern ring

Answer: (D)

In a pump stuffing box, packing rings seal around the shaft by being compressed together. The lantern ring is the spacer placed between two of those packing rings. It’s a hollow ring that provides a passage for lubricant or barrier fluid to reach the packing, helping keep the packing lubricated and cool and reducing shaft wear. This lubrication path is what makes the lantern ring distinct from the other components: the gland is what compresses the packing, the packing ring is the actual seal, and a quill ring is another type of packing element—but only the lantern ring serves as a spacer between packing rings to supply lubrication.