Are fail close pneumatic actuators affected by long - term storage?

As a supplier of fail close pneumatic actuators, one question that often comes up from our customers is whether these actuators are affected by long - term storage. In this blog, I'll delve into this topic, exploring the potential impacts and how to mitigate them.

Understanding Fail Close Pneumatic Actuators

Before we discuss the effects of long - term storage, it's important to understand what fail close pneumatic actuators are. These actuators are designed to close a valve automatically when there is a loss of air pressure. They are widely used in various industries, such as oil and gas, chemical, and water treatment, where safety and process control are of utmost importance.

The basic components of a fail close pneumatic actuator include a piston, cylinder, springs, and seals. When air pressure is applied, the piston moves against the spring force to open the valve. When the air pressure drops, the spring force pushes the piston back, closing the valve.

Potential Impacts of Long - Term Storage

1. Seal Degradation

Seals are a critical component of pneumatic actuators as they prevent air leakage and ensure proper operation. During long - term storage, seals can be affected by several factors. Exposure to oxygen in the air can cause oxidation, which may lead to hardening and cracking of the seal material. Temperature and humidity also play a significant role. High humidity can cause corrosion on the metal parts in contact with the seals, and extreme temperatures can accelerate the degradation process.

For example, if an actuator is stored in a damp environment, the rubber seals may absorb moisture, leading to swelling and a loss of their sealing properties. Once the actuator is put back into service, air leakage may occur, which can compromise the performance of the valve.

2. Spring Fatigue

The springs in a fail close pneumatic actuator are responsible for closing the valve when the air pressure is lost. Over time, springs can experience fatigue, especially if they are stored in a compressed state. Spring fatigue can reduce the spring's ability to generate the necessary force to close the valve properly.

If the spring loses its elasticity, the valve may not close completely, or it may take longer to close. This can be a serious issue in applications where a quick and complete valve closure is required for safety reasons.

3. Corrosion of Metal Parts

Most pneumatic actuators have metal components, such as pistons, cylinders, and fasteners. These metal parts are susceptible to corrosion during long - term storage. Corrosion can occur due to exposure to moisture, oxygen, and certain chemicals in the environment.

For instance, in a coastal area where the air contains salt particles, the metal parts of the actuator can corrode more rapidly. Corrosion can cause pitting on the surface of the metal, which can affect the smooth movement of the piston and increase friction. This, in turn, can lead to reduced efficiency and increased wear and tear on the actuator.

4. Contamination

During storage, the actuator can be exposed to dust, dirt, and other contaminants. These contaminants can enter the actuator through small openings and accumulate over time. If the contaminants reach critical areas such as the piston - cylinder interface or the air passages, they can cause blockages or abrasion.

A blockage in the air passage can prevent the proper flow of air, leading to inconsistent valve operation. Abrasion caused by contaminants can damage the surface of the metal parts, further reducing the performance and lifespan of the actuator.

Mitigating the Effects of Long - Term Storage

1. Proper Packaging

Proper packaging is essential to protect the actuator during long - term storage. The actuator should be cleaned thoroughly before packaging to remove any dirt or debris. It can then be wrapped in a protective material, such as a plastic film or a corrosion - inhibiting paper. The packaging should be designed to prevent moisture and dust from entering.

Additionally, the actuator can be stored in a sealed container with a desiccant to absorb any moisture inside the container. This helps to maintain a dry environment and reduces the risk of corrosion and seal degradation.

2. Storage Conditions

The storage environment plays a crucial role in minimizing the effects of long - term storage. The actuator should be stored in a clean, dry, and temperature - controlled area. The ideal temperature range for storage is typically between 10°C and 30°C, and the relative humidity should be kept below 60%.

If possible, the actuator should be stored in an upright position to prevent any stress on the springs and other components. Avoid storing the actuator near sources of heat, chemicals, or direct sunlight, as these can accelerate the degradation process.

3. Periodic Inspection and Maintenance

Even during storage, the actuator should be inspected periodically. This allows for the early detection of any potential issues, such as seal degradation or corrosion. If any problems are identified, appropriate measures can be taken, such as replacing the seals or treating the corroded parts.

Before putting the actuator back into service, a full functional test should be conducted to ensure that it is operating properly. This includes checking the valve's opening and closing times, the sealing performance, and the overall functionality of the actuator.

Related Products

If you are interested in other types of pneumatic actuators, we also offer a Pneumatic Gate Valve with Side Handwheel, which provides additional manual control options. Our Fail Open Pneumatic Actuator is designed for applications where the valve needs to open automatically when there is a loss of air pressure. And for high - pressure applications, we have the High Pressure Pneumatic Actuator.

Conclusion

In conclusion, fail close pneumatic actuators can be affected by long - term storage, but with proper storage and maintenance practices, these effects can be minimized. As a supplier, we are committed to providing high - quality products and ensuring that our customers have the knowledge and resources to take care of their actuators.

If you are in need of fail close pneumatic actuators or have any questions regarding their storage and maintenance, we invite you to contact us for procurement and further discussions. We have a team of experts who can provide you with the best solutions for your specific needs.

References

1. "Pneumatic Actuator Handbook", Industrial Press Inc.
2. "Valve Technology and Applications", McGraw - Hill Education.
3. Technical papers on pneumatic actuator maintenance from industry associations.