Actuation
What is a Valve Actuator?
Valve actuators are mechanical devices that provide the power to operate valves, allowing them to open and close.
When selecting a valve actuator, several factors must be considered, including the valve type and size, the required torque and speed, the operating environment, the available power source, and the desired level of control and automation. By carefully considering these factors, you can ensure the selection of a valve actuator that will provide efficient and reliable operation of your systems.
Actuators & MOV Valves
United Valve offers actuation sales and valve repair services on both electric and pneumatic actuators, as well as motor-operated (MOV) valves. We specialize in actuated valve packages and the procurement of highly engineered valves for many industrial applications.
With the involvement of our engineering staff and our decades of experience, we can decipher the most complex customer specifications and offer solutions that meet or exceed all customer requirements and deliver them quickly.
MOV Valves & Repair Services
MOV stands for Motor Operated Valve. It’s essentially a valve with an electric motor attached to automate its operation. This allows for remote control and precise operation, especially for large valves that would be difficult to operate manually. MOV Valves are used in several industries, including oil and gas, power generation, water treatment, and manufacturing.
We are highly experienced in critical MOV valve repair. We can easily diagnose problems, determine whether issues lie with the actuator or the valve, and then mitigate the problem. With our large hydrostatic testing machines, we can also performance test MOV valves to ensure they are operating correctly under pressure. Our industrial valve service can help your systems run smoothly.
Types of Valve Actuators We Service
Not all actuators operate the same way. Choosing — or repairing — the right one starts with understanding how each type delivers force to the valve.
Electric Actuators Electric actuators use a motor to convert electrical energy into the rotational or linear force needed to open and close a valve. They offer precise positioning, easy integration with control systems, and remote operability, making them a common choice for MOV valves in refineries, power plants, and water treatment facilities. Because they don’t require a separate air or hydraulic supply, electric actuators are often favored in locations where compressed air isn’t readily available.
Pneumatic Actuators Pneumatic actuators use compressed air to drive a piston or diaphragm, producing fast, reliable actuation. They’re widely used in oil and gas processing units where instrument air is already part of the plant infrastructure. Pneumatic actuators tend to offer excellent fail-safe performance — spring-return designs can automatically drive a valve to a safe position if air supply is lost, which is critical for emergency shutdown (ESD) applications.
Hydraulic Actuators For applications requiring very high torque or thrust — large diameter valves, high-pressure systems, or subsea and offshore equipment — hydraulic actuators deliver the force electric or pneumatic units often can’t. They use pressurized hydraulic fluid to generate motion and are common on large gate, ball, and plug valves.
Quarter-Turn vs. Multi-Turn Actuators Actuators are also classified by the type of motion they produce:
- Quarter-turn actuators rotate the valve stem 90 degrees and are used on ball, butterfly, and plug valves.
- Multi-turn actuators rotate the stem through multiple full rotations and are typically paired with gate and globe valves, where the valve closure element travels linearly as the stem turns.
Signs Your Actuator or MOV Valve Needs Service
Catching actuator problems early prevents unplanned downtime and costly emergency repairs. Common warning signs include:
- Inconsistent or slow valve response to control signals
- Unusual noise, vibration, or heat coming from the actuator housing
- Torque or thrust readings outside the manufacturer’s specified range
- Failure to reach full open or full closed position
- Error codes or communication faults on electric actuators with smart positioners
- Visible fluid leaks on hydraulic or pneumatic units
If you’re noticing any of these symptoms, it’s worth having a technician diagnose whether the root cause is the actuator, the valve, or the connection between the two — a distinction that isn’t always obvious without hands-on inspection.
Industries We Serve
- Oil & Gas — refineries, gas processing plants, and pipeline facilities relying on precise, fail-safe valve control
- Power Generation — steam, gas, and nuclear facilities where MOV valves are essential to safe plant operation
- Water & Wastewater Treatment — municipal and industrial systems requiring reliable remote valve control
- Petrochemical Manufacturing — process units where actuator reliability directly affects production uptime
Our experienced engineering staff is capable of handling a diverse range of actuation challenges, ensuring your systems operate as expected. For actuator service or industrial repairs for MOV valves, contact us directly and we can take care of the rest.
Frequently Asked Questions
How do I know if I need an electric or pneumatic actuator? It depends on your available infrastructure, required response speed, fail-safe requirements, and whether precise positioning or simple open/close control is needed. Our engineering staff can evaluate your application and recommend the right fit.
Can you repair actuators from any manufacturer? We work on a wide range of electric, pneumatic, and hydraulic actuators. Bring us your specifications or the actuator itself, and we’ll diagnose the issue and outline repair options.
What’s the difference between actuator repair and valve repair? The actuator provides the force to move the valve; the valve itself controls flow. A malfunction can originate in either component, or in the coupling between them. Our diagnostic process isolates the source of the problem before recommending a repair path.
Do you offer on-site actuator service, or is everything done in-shop? We offer both, depending on the size of the equipment and the nature of the issue. Field service is often used for large, difficult-to-transport MOV valves, while smaller units can be brought into our shop for full testing and repair.