Reasons Why Butterfly Valves Fail to Fully Close and Solutions: Keep Your Valves in Top Condition

1. Incorrect Operation: The Most Common Cause of Failure

One of the most overlooked yet common reasons is incorrect operation. If a manual butterfly valve is not closed following the correct procedure, it may remain partially open, giving the impression that it won’t fully close. This is particularly common in large pipeline systems where the valve needs to be operated with the specified torque. Incorrect operation can result in incomplete closure.

Solution Steps:
Recheck the operation of the butterfly valve to ensure it has been fully closed.

If it’s an electric or pneumatic valve, check if the actuator is functioning correctly.

When closing the valve, apply force gradually, avoiding excessive speed or force to prevent damaging the sealing surface.

2. Damaged Sealing Surface: The Key to Leaking Valves

Another common cause of a butterfly valve failing to close is a damaged sealing surface. Over time, the sealing surface of the valve may wear down, corrode, or age, reducing its sealing effectiveness and preventing the valve from fully closing. This is especially common in high-temperature, high-pressure, or corrosive environments.

Solution Steps:

Regularly inspect the sealing surface of the valve.

If significant wear or corrosion is found, replace the sealing component to ensure proper sealing.

In harsh environments, consider upgrading to wear-resistant or corrosion-resistant materials to prolong the valve’s service life.

3. Obstructions: The Hidden Culprit Behind Incomplete Closure

In industrial pipelines, the fluid often carries impurities, particles, or scale, which can cause obstructions within the valve. These obstructions, especially in water treatment and wastewater systems, can accumulate at the valve seat, preventing the butterfly plate from fully closing, thus compromising the valve’s sealing performance.
Solution Steps:
Regularly flush and clean the pipeline to avoid the accumulation of debris near the valve.

If the valve is not closing properly, disassemble the valve and check for foreign objects, cleaning them out if necessary.

Installing filters in the system can reduce the risk of obstructions, ensuring the valve operates smoothly.

4. Lack of Lubrication: Leading to Difficult Operation

Over time, if the moving parts of the butterfly valve lack lubrication, it may become difficult to operate, or in some cases, impossible to fully close. This issue is common in manual or mechanical butterfly valves that have not undergone routine maintenance. Without adequate lubrication, increased resistance can prevent the valve plate from fully closing and sealing.

Solution Steps:

Regularly lubricate the shaft, bearings, and other moving parts of the butterfly valve to ensure smooth operation.

Use high-temperature or corrosion-resistant lubricants for valves operating in harsh conditions.

If the valve is already stuck due to lack of lubrication, stop operation immediately and perform maintenance to prevent further damage.

5. Damaged Valve Components: Replace Parts to Restore Functionality

Key components of the butterfly valve, such as the disc, shaft, and bearings, can wear out or become damaged over time due to wear, corrosion, or mechanical stress. When these components are damaged, the valve’s sealing and operation are directly affected, leading to a failure to fully close.

Solution Steps:

Inspect the critical components of the butterfly valve, particularly the disc and bearings, for signs of wear.

If any damage is found, replace the components immediately to restore proper valve functionality.

Selecting higher-quality components that match the working conditions can extend the service life of the valve and reduce maintenance costs.

Conclusion

The issue of butterfly valves failing to fully close may seem common, but the underlying causes can vary. To ensure optimal performance in your daily operations, regular maintenance, proper operational procedures, and timely replacement of damaged components are essential. If you encounter any problems with your butterfly valves, feel free to contact us at Weizidom. We not only offer high-quality butterfly valve products but also provide expert technical support and solutions to keep your operations running smoothly.