What type of valve is used to make relatively fine adjustments?

The needle valve is specifically designed for making precise adjustments in flow control, which is why it is the correct answer. Its construction includes a long, tapered needle that fits into a matching seat, allowing for fine-tuning of fluid flow. This design enables very small adjustments to the flow rate, making needle valves ideal for applications where accuracy is critical, such as in laboratory settings or where fluid dynamics need meticulous control.

In contrast, while the ball valve and butterfly valve are effective at providing on/off flow control, they are not designed for fine adjustments. A ball valve has a spherical closure element that fully opens or closes the flow, which is more suited to applications requiring quick shut-off rather than precise modulation. Similarly, the butterfly valve is efficient for regulating flow but generally operates in a more binary manner—open or closed—rather than facilitating subtle changes.

The globe valve, although it can be used for throttling flow and is better than a ball or butterfly valve in that regard, does not provide the same level of precision as a needle valve. Its design is more focused on pressure drop management and is less efficient at achieving very fine control compared to a needle valve’s capability.

Thus, the needle valve stands out as the best choice for applications needing accurate