What is the Difference Between an Actuator and an Industrial Valve?

Valves and actuators are often considered one piece for fluid and gas control in industrial processes. However, they are two separate components.

The valve is the component that actually controls flow of the processing liquid or gas. The interior parts of the valve open and close to help with isolation, mixing, and throttling. Industrial valves can be opened and closed in a variety of ways. Some valves are manually operated, requiring human operation. However, many severe service applications use actuation to automatically open or close the valve as needed.

Actuators are what allow that automated process to happen without human intervention. The actuator acts upon the valve stem to open or close the valve. There are many different types of actuators, so it’s important to choose the one that is best for your application.

Valve actuator types include:

Pneumatic
Hydraulic
Electric

There are any number of combinations to choose from for valve and actuator type. Our actuator repair technicians work on all valve and actuator pairings to help restore functionality to your valve actuators.

Despite being two different components, they are both essential for valve cycling. In failure situations, it can be difficult to know whether the actuator or the valve is the root cause of the problem.

Do I Need Actuator Repair or Valve Repair?

When a valve is stuck in one position, it’s often challenging to know whether it is a valve issue or an actuator issue. Our actuator repair technicians can help identify the root cause of the problem. If it is an actuator issue, we offer quality industrial valve actuator repair services on site or in our shop. For valve issues, our sister company, Southern Valve Service, can provide the repairs you need for your industrial valves.

Some of the most common causes of industrial valve actuator failure include:

Damaged Center Column: The center column is the part of the actuator that attaches to and acts upon the valve stem. If this piece fails, then the actuator can’t automatically turn the valve stem for process control.
Connection Failure: The connection between the actuator and the valve is important for allowing actuation to work properly. Typically, this connection is a drive nut to connect the valve stem and the center column of the valve actuator. If this becomes damaged or fails, then the actuator cannot open or close the valve.
Motor Contactor Failure: In electric actuators for motor operated valves, the contactor is a relay that turns the electrical circuit on or off. This controls whether the actuator turns the valve on or off using power from the motor. This can malfunction and cause valve control failure.
Motor Failure: Motors in electric actuators can also fail for a variety of reasons, from poor lubrication to overheating. Without the motor to provide power to the valve actuator, the valve can’t be opened or closed using actuation.
Solenoid Ports Plugged: In pneumatic actuators, a solenoid valve directs air in and out of the actuator to control valve position. If these ports in the solenoid become clogged, the actuator may fail.
Low Hydraulic Fluid: In hydraulic industrial valve actuators, actuation may fail if the hydraulic fluid is too low as it can’t reach pressures strong enough to move the valve actuator.

In other cases, issues with actuation may actually be due to valve components. For instance, some common malfunctions include:

Damaged Valve Stem: If the valve stem becomes damaged or worn, it will not respond to actuation.
Obstructions: Obstructions in the valve opening can prevent the disk from closing, which may appear like an actuation problem at first.
Thermal Binding: It may be that the gate can become jammed due to thermal binding. This is particularly true in high temperature applications.

Whatever the issue with your control valves, our team at Southern Actuation Service is here to provide the repairs you need to restore your operations. We offer quality shop and field actuator repair services. If the valve is to blame, our team at Southern Valve Service can assist with industrial valve repair and remanufacturing.