Which is at the top of the stuffing box?

The packing gland is the component located at the top of the stuffing box. The packing gland serves a critical function in the overall operation of equipment such as pumps and valves by providing a means to compress the packing material contained within the stuffing box. This compression is essential to create a seal that prevents leakage of fluids along the shaft or rod.

The packing gland typically consists of a threaded nut that can be adjusted to tighten or loosen the packing material, allowing for maintenance or replacement as needed. Proper adjustment of the packing gland ensures that an effective seal is maintained, which is vital for preventing leaks and optimizing the efficiency of the hydraulic system.

In contrast, the lantern ring, mechanical seal, and seal cage play different roles within the sealing assembly and do not occupy the top position within the stuffing box. The lantern ring may be included as part of the packing arrangement to facilitate lubrication, while the mechanical seal replaces conventional packing in many modern applications. The seal cage serves as a structural element to house and hold the mechanical seal.