Which component in a control system regulates flow rates?

In a control system, a flow control valve is specifically designed to regulate flow rates within a system. The function of this component is to adjust the opening and closing based on the feedback it receives from other system components, such as flow sensors. This adjustment helps maintain the desired flow rate that is necessary for optimal system performance.

When controlling flow rates, it’s crucial to have a device that can actively alter the flow based on the control signal received. A flow control valve does this effectively by either restricting or allowing the passage of fluid, thus achieving the required flow rate as dictated by the system's control strategy.

Other components, while essential in control systems, have different primary functions. For example, a pressure sensor measures pressure within a system but does not have the capability to regulate flow. Similarly, a temperature controller primarily manages temperature levels and does not directly influence flow rates. A level measuring device focuses on detecting the level of liquids rather than directly controlling the flow of fluids. Hence, the flow control valve is the correct answer, as it directly serves the purpose of regulating flow rates in control systems.