What is fitted on the shaft outboard of the stuffing box glands to prevent leakage?

The correct answer is that a water flinger is fitted on the shaft outboard of the stuffing box glands to prevent leakage. The primary function of the water flinger is to redirect water away from the stuffing box area. It works by creating centrifugal force as the shaft rotates, which helps to keep water from entering the shaft seal area and reduces the risk of leakage.

In the context of a gas turbine system, preventing leaks can help maintain system efficiency and protect sensitive components from potential damage caused by leaks. If water or other fluids were to infiltrate, it could lead to corrosion or operational issues over time.

Other components mentioned, like the seal ring and compression gland, serve specific purposes in sealing and securing connections but do not provide the same preventative function against leakage that a water flinger does. A drain plug is used primarily for maintenance or to facilitate draining fluids, and does not contribute to preventing leakage at the stuffing box. Hence, the design and purpose of the water flinger highlight its critical role in managing shaft seals and preventing leaks effectively.