What component maintains tension on pump packing in the stuffing box?

The packing gland is the component that maintains tension on the pump packing within the stuffing box. Its primary function is to provide sufficient pressure against the packing material, which helps to create a seal and prevent leakage of liquids from the pump. By adjusting the packing gland, operators can control the tightness of the seal and ensure that the packing remains effective over time. This mechanism is crucial for the longevity and efficiency of the pump, as well as for preventing environmental contamination from leaks.

In contrast, other components such as the check valve, sealing ring, and inspection plate serve different purposes. A check valve is designed to allow fluid to flow in one direction only, preventing backflow. The sealing ring may be part of the assembly that contributes to sealing but does not specifically adjust tension. The inspection plate allows access for maintenance or inspection but does not play a role in maintaining packing tension. Thus, the packing gland is uniquely responsible for keeping the packing in place and providing the necessary support to maintain an effective seal in a pump.