Is Your Valve Actuator Failing

A malfunctioning valve actuator can bring a process to a standstill, leading to costly downtime and lost productivity. Whether you're in a municipal water plant, a chemical facility, or an oil & gas operation, understanding the warning signs of a failing actuator is critical for proactive maintenance.

Symptom 1: No Response When Activated 

This is the most obvious sign of a problem. You send a signal to open or close the valve, but nothing happens. The actuator remains motionless.

• Initial Troubleshooting: First, verify that the actuator is receiving power and the correct control signal. A faulty wire, a blown fuse, or a tripped circuit breaker can be the culprit. Check the control panel and power source before assuming the actuator is bad.

• Expert Insight: If the power and signal are both confirmed to be good, the issue is almost certainly internal. For electric actuators, this could mean a complete motor failure or a fried control board. For pneumatic or hydraulic actuators, a snapped spring, a broken piston, or a loss of air/fluid pressure could be the root cause.

Symptom 2: Slow or Inconsistent Movement 

The actuator moves, but it struggles. It may open or close much slower than usual, or it might move in jerky, inconsistent bursts. This is often an early warning sign of a problem that is about to become a full-blown failure.

• Initial Troubleshooting: For pneumatic actuators, check the air supply. A drop in pressure can directly impact the actuator’s speed. For all types, a lack of lubrication on the valve stem or a buildup of debris can create excessive friction, making the actuator work harder.

• Expert Insight: The most common mechanical issue is excessive torque. This means the actuator has to generate more force than it's designed for. This could be due to a sticky or seized valve, or it might signal that the actuator's internal gears are wearing down. For electric actuators, a dying motor or a weak power supply can also cause a significant drop in performance.

Symptom 3: Unusual Noises During Operation 

A healthy actuator should operate with minimal noise. Any new or strange sounds—such as humming, grinding, clicking, or rattling—are a clear indication that something is wrong.

• Initial Troubleshooting: Humming in an electric actuator often means the motor is trying to turn but is unable to, which can lead to overheating. Grinding noises almost always point to worn or broken gears. Clicking in an electric actuator can indicate that a thermal overload protector is tripping on and off, trying to protect the motor from damage.

• Expert Insight: Don't ignore these sounds. A grinding noise signals that irreversible damage is being done to the internal gears. It’s a sign that the actuator needs to be serviced immediately to prevent total failure.

  
  

Symptom 4: Overheating 

An electric actuator that is hot to the touch during or after operation is a serious red flag.

• Initial Troubleshooting: A motor will naturally get warm, but it should not be excessively hot. Overheating is typically caused by the motor drawing too much current, a sign it is working too hard. This is often due to a mechanical issue with the valve, such as a stuck gate or disc, forcing the actuator to operate against excessive torque.

• Expert Insight: Overheating can also be caused by a short in the motor windings. Either way, a hot actuator means its internal components are being stressed beyond their limits. Continued operation in this state will quickly lead to motor failure.

Symptom 5: Leaking Fluid or Air 

This symptom is specific to hydraulic and pneumatic actuators and is a clear sign that a seal has failed.

• Initial Troubleshooting: For pneumatic actuators, listen for a hissing sound around the cylinder or connections. For hydraulic units, look for visible oil leaks on the actuator housing or around the seals.

• Expert Insight: Leaking fluid or air means the actuator is losing the pressure it needs to generate force. This will lead to a significant loss of torque and a complete inability to operate the valve. A leaking seal can also allow contaminants to enter the system, leading to further damage.