Control valves are considered which type of control element?

Control valves are classified as primary control elements because they have a direct role in regulating the flow of fluids in a system based on the control signal they receive. The primary purpose of a control valve is to adjust the flow rate, pressure, or temperature of a medium, thus directly impacting the process being controlled.

In a typical control system, a primary control element interacts with the manipulated variable, such as flow rate or pressure, to maintain the desired set point. Control valves respond to signals from controllers, utilizing mechanisms like modulating or on/off control, thereby facilitating the essential adjustments to the process.

The other categories of control elements typically involve other functions, such as feedback mechanisms or initiating processes, which are not the primary functions of control valves. These distinctions underline the importance of understanding where control valves fit within the broader context of control systems in power engineering.