Which valve is most likely to cause leakage?

Gate valves are primarily designed for on/off service and are not generally used for throttling. They operate with a sliding gate that moves up and down to open or close the flow of fluid. The sealing mechanism relies on a wedge that compresses against the seats to prevent leakage. However, over time, wear and tear on the seats, as well as the valve's design, can lead to a less effective seal when the valve is closed.

Gate valves can be prone to leakage, particularly when they are not used regularly or if they are installed in conditions that create pressure differentials or vibration. Their inability to provide a tight seal after prolonged use contributes to their likelihood of leaking. Therefore, in systems where preventing leakage is crucial, alternative valve types that are designed for better sealing, such as ball or globe valves, are often preferred.