Which type of valve will have the highest head loss when fully opened?

The globe valve demonstrates the highest head loss when fully opened due to its design and functionality. This valve type has a significant amount of resistance to fluid flow because of its internal components. The straight-line path of the flow through a globe valve is not optimal; it involves changes in direction which creates turbulence and increases frictional losses.

In contrast, ball and butterfly valves are designed for minimal flow resistance and are generally more efficient with lower head losses when fully opened. The gate valve is also designed for nearly unobstructed flow and tends to have lower head losses than a globe valve when fully opened. Therefore, among these options, the globe valve is recognized for its distinctive structure that leads to greater pressure drops and higher head loss during operation.