What is a common feature of gate valves?

Gate valves are designed primarily for on/off control of fluid flow, and one key feature is that when they are fully open, they offer a clear, unobstructed passage for the fluid. This characteristic allows for minimal pressure drop and ensures that the fluid can flow freely without resistance, making gate valves particularly well-suited for fully open or fully closed applications.

In contrast, the other options describe features that are not typical or appropriate for gate valves. For instance, they are not ideal for throttling flow; doing so can cause damage to the valve and lead to wear over time. Gate valves can indeed be used in high-pressure situations, contrary to some other gate valves' limitations. Lastly, they don't have a quick-acting mechanism; instead, they typically require more rotation to completely open or close compared to other types of valves such as ball valves. Thus, the clarity of passage when fully open is what distinguishes gate valves in their design and application.