What is the primary function of a needle valve?

The primary function of a needle valve is to precisely control and regulate the flow rate of a liquid or gas. This type of valve is designed with a slender, tapered point that can be adjusted to make fine changes in the flow. Unlike other valves that may allow for quicker opening or closing, needle valves provide the ability to make minute adjustments, enabling operators to achieve specific flow rates as needed in various applications. This precision is particularly important in processes where even slight variations in flow can impact the overall system performance or product quality.

In contrast, other options describe functions that are not the primary purpose of a needle valve. While a valve can start and stop flow, that is more characteristic of shut-off valves. Creating pressure in a fluid system is typically the role of pumps or other components, not a valve type focused on flow regulation. Filtering impurities from a fluid is the function of filtration equipment, which is distinct from the purpose of a needle valve focused on flow control. Thus, the ability to fine-tune flow rates is what distinctly defines the primary function of a needle valve.