by Motorized control valves use electric motors to position valves in process systems. They are installed on pipes to regulate flow, pressure, and level in an automated manner without direct human intervention. Control valves contain a valve plug or gate that can be adjusted to vary flow through precise positioning. Electric actuators replace pneumatic or hydraulic actuators to move the plug.
Types of Motorized Control Valves
Butterfly Valves
Butterfly valves have a disc shaped plug that pivots within the valve body to open or close flow. The Motorized Control Valves rotates the disc to any position between fully open and closed. They are well suited for on/off applications and moderate pressure drop service. Common uses include isolation, choke applications, and process throttling.
Ball Valves
Ball valves contain a spherical plug inside the valve body. The plug has port openings configured to line up with the inlet and outlet depending on position. Actuators precisely rotate the ball to modulate flow. Due to their reliable sealing capability, ball valves are often applied for isolating or regulating critical gas and liquid services.
Diaphragm Valves
A flexible diaphragm forms the sealing surface in diaphragm valves. The actuator applies pressure to the diaphragm to push the plug against its seat or away from it. This design isolates media from stem components and provides a bubble-tight shutoff even at high differential pressures. Diaphragm valves are widely implemented in sanitary, chemical, and pharmaceutical process systems.
Control Functions of Motorized Valves
On/Off Control
On/off or two-position control valves open fully to allow maximum flow or close tightly to stop flow altogether. Motorized ball valves and butterfly valves usually operate as on/off valves using a motor to select between the two states. They regulate simple processes that only require full flow or no flow.
Modulating Control
Modulating control valves have a plug that can be positioned anywhere between 0-100% open. The actuator’s Motorized Control Valves receives a signal from a controller and adjusts the plug position in small increments to regulate flow. Modulating control provides much finer regulation of process variables like temperature, pressure and fluid levels compared to on/off control.
Proportional-Integral-Derivative (PID) Control
advanced motorized valves paired with PID controllers provide precise control over process variables. The controller combines proportional, integral and derivative functions to calculate the exact plug position needed each second based on the control algorithm. PID control compensates for process nonlinearities and disturbances to maintain exceptional control stability for critical industrial processes.
Common Process Applications
Boiler and Furnace Systems
Control valves adjust fuel or air flow into combustion systems. Motorized valves quickly respond to load changes and precisely control emissions by modulating burner outputs. They regulate steam pressure and flow in boiler drum level control loops.
Chemical Processes
In chemical production, motorized control valves accurately dose reactants, measure concentrations and control reactions by regulating temperatures and flow rates of chemicals. Diaphragm valves commonly throttle corrosive or hazardous substances.
Water and Wastewater Treatment
Motorized valves adjust chemical dosing and flow paths. They regulate flows between process tanks and filter beds. Control valves maintain critical levels in sedimentation basins and ensure effluent water quality meets regulations before discharge or reuse.
Advantages of Motorized Control Valves
Remote Operation and Monitoring
Electric actuators enable valves to connect to control networks and SCADA systems for remote access and control from any location. Motorized valves eliminate the need for on-site compressed air lines.
Automatic Control
Motorized valves instantly and accurately respond to setpoint changes commanded by controllers. Automatic control maintains process variables within safe operating limits without direct human operation. This improves efficiency, product quality and safety.
Low Maintenance
With no pneumatic parts like diaphragms and seals, electric actuated valves eliminate maintenance associated with compressed air supply lines. Actuators perform reliably for years in harsh conditions with minimal servicing required.
Motorized control valves and their applications in industrial processes were examined. Electrohydraulic and electric actuator technologies precisely modulate valves remotely based on control algorithms to automatically regulate critical parameters. Due to advantages like reliability, low maintenance and networking capability, motorized valves are progressively replacing pneumatic valves as the integral control element in digitalized process systems. They make processes more efficient, safe and help achieve production targets.
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1. Source: Coherent Market Insights, Public sources, Desk research
2. We have leveraged AI tools to mine information and compile it
