What is the function of a flow control valve?

A flow control valve is designed specifically to regulate the flow rate of fluid in a hydraulic system. Its primary function is to maintain a desired speed in actuators or to ensure that the flow remains within specified limits, which is critical for the efficient operation of hydraulic systems. By adjusting either the valve's opening or passage size, the flow control valve can either restrict or allow more fluid to pass through, thus controlling the speed of hydraulic actuators such as cylinders or motors. This ability to finely adjust the flow helps in achieving precise control in various applications, ranging from industrial machinery to mobile equipment.

The other options, though related to hydraulic systems, do not accurately depict the role of a flow control valve. Measuring the temperature of hydraulic fluid is a function of temperature sensors, increasing pressure requires components like pumps or pressure relief valves, and converting hydraulic energy into electrical energy refers to devices like hydraulic generators or pumps with generator functions, which is outside the scope of what a flow control valve does.