by Motorized control valves use electric actuators to automatically adjust flow based on external inputs like temperature, pressure or flow rate. As processes become more automated, these types of motorized valves have grown in popularity across many industries.
There are several common types of Motorized Control Valves each suited to different applications and flow requirements.
Ball Valves
Ball valves are Found in both two-way and three-way configurations. They provide on/off flow control using a spherical ball and are ideal for process lines with low to moderate pressure drops. While less efficient than other options, their simplicity makes them a good choice for basic flow regulation.
Butterfly Valves
Butterfly valves use a rotating disk to partially or fully block flow through a pipe. They are compact and provide good throttling capabilities at a low cost. Applications include pump flow control, mixing processes and bypass operations. The discs require only a quarter turn to open fully, making them well-suited for on/off processes.
Globe Valves
Globe valves have a cylindrical design where the flow path goes through a full port. They are highly effective at regulating flow both linearly and tightly. This makes them suitable for applications with close flow setpoint control needs like heating and cooling systems. They tend to have higher pressure drops than other valve types.
Diaphragm Valves
Diaphragm valves use a flexible membrane that acts as a valve plug to isolate upstream and downstream pressures. They are well-suited for flow control of liquids and gases in hygienic or clean applications like food/beverage, pharmaceuticals and semiconductor industries. Self-cleaning capability makes them ideal for handling viscous or particulate-filled fluids.
Applications of Motorized Control Valves
Some common process industry applications where motorized control valves excel include:
Heating/Cooling Systems
Motorized valves allow automatic flow adjustment based on temperature readings to precisely control heat exchanger inlet conditions. This improves efficiency in systems like boilers, chillers and furnaces.
Chemical Dosing
Whether adding acids/bases for pH control or other chemicals, motorized valves are well-suited to dosing processes where accurate flow rates are critical for product quality.
Biopharm Fermentation
Control of nutrient feeds, oxygen levels and pH are important factors in bioreactor processes. Motorized valves enable precise and automatic control over multiple vessel parameters.
Pump Flow Regulation
Monitoring and controlling pump flow rates with motorized valves protects equipment, maintains optimal process conditions and prevents over/under dosing.
Waste Treatment Systems
Motorized valves help regulate flows and blending for processes like wastewater filtration, sludge processing and flue gas scrubbing systems.
Operation
Inside a Motorized Control Valves, an electric actuator opens and closes the valve in response to control signals. Common actuator types include:
Pneumatic actuators – Use compressed air and a diaphragm/piston assembly to rotate the valve stem. Require an external air supply.
Electric actuators – Contain a motor/gear assembly directly coupled to the valve stem. Convert an electrical current into linear or rotary motion. Provide highly accurate positioning without external air/fluid supplies.
Hydraulic actuators – Utilize a hydraulic fluid and piston arrangement to manipulate valve stem movement. Need an external hydraulic power unit.
The actuator receives a signal from a controller, PLC or DCS indicating the desired valve position. Feedback sensors then allow the controller to verify the actual valve position is correct. Modern smart actuators also have diagnostic capabilities to monitor actuator health and detect issues.
Benefits and Considerations
Some key advantages of motorized control valves include:
– Automatic, remote operation improves process efficiency by eliminating manual intervention
– Precise flow regulation ability through positioning feedback and digital control signals
– Vast array of valve styles suit diverse applications and media types
– Integrated valve diagnostics enhance maintenance practices
– Reduced operator error risk versus manual valve adjustment
– Ability to link multiple valve positions to one another or process variables
Motorized valve selection also requires considering installation factors like actuator power requirements, valve materials for line compatibility and control functions. Proper sizing is crucial to avoid issues from undersized or oversized valves. Additionally, long-term maintenance planning and spare parts inventories help maximize up-time.
With benefits like process optimization and reduced labor needs, motorized control valves have become indispensable tools for automated flow regulation across many industries. their operational flexibility has led to expanding uses in both traditional and emerging process applications. Through appropriate technology selection and maintenance practices, they reliably deliver precise flow control essential for quality operations.
*Note:
1. Source: Coherent Market Insights, Public sources, Desk research
2. We have leveraged AI tools to mine information and compile it
