Mechanical seals are like __ but are used with 60psig or more.

Mechanical seals are like __ but are used with 60psig or more.

• A. bearings
• B. lantern rings
• C. couplings
• D. packing rings

Answer: (D)

The key idea is that a mechanical seal serves the same purpose as packing rings—to seal around a rotating shaft—but is designed for higher-pressure service. Mechanical seals are built to handle 60 psig and above with much lower leakage and less maintenance than packing rings, which rely on gland compression of packing material. That’s why the best analogy is packing rings: they perform the same sealing function, but mechanical seals are chosen specifically for higher-pressure applications. Lantern rings and packing rings are part of traditional packing-gland systems, where lantern rings help supply barrier fluid and packing rings require periodic adjustment. Bearings and couplings do not seal the shaft; bearings support rotation and couplings connect shafts.

The key idea is that a mechanical seal serves the same purpose as packing rings—to seal around a rotating shaft—but is designed for higher-pressure service. Mechanical seals are built to handle 60 psig and above with much lower leakage and less maintenance than packing rings, which rely on gland compression of packing material. That’s why the best analogy is packing rings: they perform the same sealing function, but mechanical seals are chosen specifically for higher-pressure applications.

Lantern rings and packing rings are part of traditional packing-gland systems, where lantern rings help supply barrier fluid and packing rings require periodic adjustment. Bearings and couplings do not seal the shaft; bearings support rotation and couplings connect shafts.