Why is a needle valve preferred for low-flow applications?

A needle valve is preferred for low-flow applications primarily because it provides fine adjustments to the flow rate. The design of a needle valve allows for a small opening that can be adjusted very precisely, making it ideal for controlling the flow of liquids or gases in situations where minimal flow is needed. The long, tapered point of the needle within the valve body fits snugly in the valve seat, allowing for granular control over the amount of fluid that passes through. This level of precision is crucial in applications such as laboratory experiments, fuel systems in engines, or any scenario where slight variations in flow can significantly impact performance or results.

While the ability to handle high pressures, cost considerations, and space efficiency may also be important attributes in certain contexts, they do not directly relate to the primary advantage of a needle valve being its capability for fine flow adjustments, which is critical in low-flow applications.