Why Do Butterfly Valves Fail and How to Prevent It?

Butterfly valves are a popular choice for flow control in various industries due to their compact design, quick operation, and cost-effectiveness. However, like any mechanical component, they are susceptible to failure over time. One of the primary reasons for butterfly valve failure is related to the seating mechanism within the valve. Additionally, the unique design of a butterfly valve, where the disc extends beyond the face of the valve body and may rest at the same angle as the opening when installed between flanges, can contribute to potential issues.

Seating Mechanism Failure

The seating mechanism in a butterfly valve is responsible for creating a tight seal when the valve is closed. Over time, the seating material can wear down, leading to leaks and eventual failure. Factors that can contribute to seating mechanism failure include:

Frequent cycling of the valve
Exposure to harsh chemicals or abrasive materials
Improper installation or maintenance
Extreme temperatures or pressures

To prevent seating mechanism failure, it’s essential to choose a valve with a seating material that is compatible with the fluid being handled and the operating conditions. Regular maintenance, such as inspecting the seating for wear and replacing it if necessary, can also help extend the valve’s lifespan.

Disc Position and Flange Interference

The unique design of a butterfly valve, where the disc extends beyond the face of the valve body, can lead to potential issues when installed between flanges. If the disc is not properly aligned with the flanges, it can cause interference and lead to premature failure. Additionally, if the disc rests at the same angle as the opening when installed, it may not create a tight seal, leading to leaks.
To prevent issues related to disc position and flange interference, it’s crucial to ensure that the valve is properly aligned during installation. This includes ensuring that the flanges are parallel and that the valve is centered between them. Additionally, it’s important to follow the manufacturer’s recommendations for bolt torque and gasket placement to create a tight seal.
In conclusion, while butterfly valves are a reliable and cost-effective choice for flow control, they are not immune to failure. By understanding the potential causes of failure and taking steps to prevent them, such as choosing the right seating material, performing regular maintenance, and ensuring proper installation, you can extend the lifespan of your butterfly valves and minimize the risk of costly downtime and repairs.