In a cooling water system, what is the effect of using a globe valve compared to a gate valve when both are fully open?

In a cooling water system, using a globe valve compared to a gate valve when both are fully open results in a larger head loss and smaller flow rate with the globe valve. This is because the design of a globe valve includes a tortuous flow path that the fluid must navigate. The shape of the internal components creates more resistance to the flow, which increases the frictional losses in the system. As a result, even when the globe valve is fully open, the flow is still constrained, leading to a higher head loss relative to a gate valve that provides a straight, unobstructed passage for the fluid.

Gate valves are specifically designed to minimize flow resistance and will generally allow for a greater flow rate when fully open, as they offer a clear path for fluid movement. Thus, while the globe valve may control flow more effectively in certain applications (like throttling), it introduces more head loss compared to a gate valve, making it less effective for systems that require maximum flow efficiency.