🔍 Key Concepts

• stuffing box function on a centrifugal pump shaft • how shaft sleeves or other components protect the shaft surface from packing, erosion, and corrosion • the primary purpose of wearing rings vs other pump wear parts

💭 Think About

• Which component is specifically designed to be a sacrificial, replaceable surface where packing or erosion would otherwise damage the shaft? • Think about where the stuffing box is located and which part of the pump assembly actually sits under the packing in that area. • Which choice is normally inexpensive and easy to replace during maintenance, instead of replacing or machining the whole shaft?

✅ Before You Answer

• Verify which part is located at the stuffing box along the shaft, not at the impeller eye or casing. • Check which item’s main purpose is to be renewable/replaceable to protect the shaft, not mainly to improve lubrication or distribution of sealing water. • Confirm which component is most commonly used on marine centrifugal pumps in the stuffing box area as a sacrificial wear part.