Actuated Valves

• Definition: These valves use an external force or mechanism to open or close. This force can be provided by various actuators, such as pneumatic, hydraulic, or electric.  
• Functionality: Actuated valves often perform simple on/off functions or maintain a specific position. They are not designed for precise flow control.  
• Examples: Gate valves, ball valves, Butterfly valves and plug valves are common types of actuated valves.

Control Valves

• Definition: Control valves are a specialized type of actuated valve designed to regulate flow rates precisely based on a control signal.  
• Functionality: These valves use a controller to receive a signal (e.g., from a process variable sensor) and adjust the valve position accordingly. This allows for precise control of flow rates, pressure, temperature, or other process parameters.  
• Examples: Globe valves, butterfly valves, and diaphragm valves are often used as control valves.

Key Differences: Actuated valves are used for basic flow control, while control valves provide precise regulation based on external signals. The choice between the two depends on the specific requirements of the process.