If a globe valve is used on the feedwater piping, where should the disk be positioned relative to the inlet?

In the context of using a globe valve on feedwater piping, positioning the disk below the inlet is crucial for proper valve operation and performance. When the disk is located below the inlet, it allows for effective sealing against the flow direction when the valve is closed, preventing backflow and ensuring that the feedwater flows smoothly into the system when the valve is open.

This positioning enhances the flow characteristics through the valve, as it minimizes turbulence and allows for a more streamlined flow path. Additionally, having the disk below the inlet reduces the risk of water hammer, which can occur if the flow experiences abrupt changes in pressure due to poor valve positioning.

In contrast to other options, positioning the disk above or at the same level as the inlet could lead to inefficiencies and mechanical complications, as noted in the context of water flow dynamics and valve operations. The design of the globe valve inherently benefits from having the disk positioned below the inlet to ensure optimal functionality within feedwater systems.