What is the main function of a lantern ring in a pump system?

The primary function of a lantern ring in a pump system is to allow water to enter the packing. The lantern ring is typically incorporated into the stuffing box of a pump and serves as a conduit for external sealing fluid, such as water or another compatible fluid, to be introduced into the packing area. This introduction of fluid helps to cool and lubricate the packing material, reducing wear and extending its life.

By enabling the packing to be saturated with liquid, the lantern ring ensures proper sealing around the shaft, preventing leakage while also managing the temperature within the stuffing box. This is a critical component in maintaining the efficiency and reliability of the pump system, as effective sealing is necessary to prevent fluid loss and maintain system pressure.

While the other options relate to different aspects of pump function or fluid dynamics, they do not capture the specific role of the lantern ring in facilitating the proper operation of the packing within the pump.