Mechanical Packing Nomenclature

This figure illustrates key components of a compression packing system. Industrial plant operators spend a lot of time inspecting and adjusting compression packing. Therefore, it is important for the operators to learn the names of the key components. The purpose of the key components is described below:

a. Stuffing Box (or Stuffing Box Area): The stuffing box is used to house the packing material. The stuffing box forms the boundary between the wet side and the dry side of a pump. In the illustration provided here, the wet (inner) side of the pump is on the left hand side, and the dry (outer) side is on the right hand side of the stuffing box.

b. Packing: The packing consists of a series of rings constructed with a suitable packing material.

c. Lantern Ring: The purpose of the lantern ring is to facilitate injection of cooling water into an intermediate point in the packing ring assembly. In the next section lantern rings are illustrated.

d. Water Inlet Port: This port is used to allow cooling water to flow into the stuffing box. The incoming water, after it enters the stuffing box, flows in two directions along the shaft: left toward the wet side of the pump, and right towards the outer region. In most pumps you will see water leaking out of the stuffing box. This water serves two purposes: provides cooling as well lubrication.

In some cases, especially in vertical pumps, stuffing box is lubricated with oil rather than water.