Which assembly is responsible for holding the lantern ring and packing?

The stuffing box is the assembly responsible for holding the lantern ring and packing. It is a crucial component in pump design, particularly in centrifugal pumps, used to prevent leakage of fluids along the shaft. The lantern ring serves to allow for a steady flow of lubrication and cooling to the packing material, which surrounds the shaft. Proper function of the stuffing box ensures that the packing maintains the necessary pressure to reduce leakage while allowing the shaft to rotate freely.

In contrast, the discharge cover serves primarily to direct fluid flow out of the pump and does not play a role in retaining the lantern ring or packing. The suction manifold is involved in drawing fluid into the pump, focusing on the inflow rather than the sealing mechanism around the shaft. The volute casing is designed to convert the kinetic energy of the fluid into pressure and shape the flow direction, but it also does not have the function of holding the lantern ring and packing. Thus, the stuffing box is specifically designed for this purpose, making it the correct choice.