Butterfly valves are widely used as regulating and shut-off devices in industrial piping systems, valued for their simple structure, lightweight design, and rapid open-close operation. They find applications across water treatment, chemical, metallurgical, power, oil, and gas industries.

 

However, even high-quality butterfly valves can experience performance degradation if proper maintenance is neglected over long-term operation.This article explores the structural features, common issues, and maintenance practices to help effectively extend the service life of butterfly valves.

 

1. Understanding the Operational Characteristics of Butterfly Valves

 

A butterfly valve primarily consists of a valve body, disc, stem, sealing elements, and an actuator. Its operation relies on the rotation of the disc, driven by the stem, to control fluid flow.

 

During operation, the disc remains immersed in the fluid, subject to erosion, corrosion, and pressure shocks. Therefore, the valve’s lifespan is closely related to sealing performance, material selection, and the operating environment.

 

2. Common Factors Affecting Butterfly Valve Lifespan

 

Frequent Operation and High Differential Pressure

High-frequency cycling or prolonged operation under high pressure and flow velocity can cause valve seat wear and stem seal aging.

 

Corrosive Media and Sediment Build-Up

Chemical fluids or particulate-laden media can corrode the disc and clog sealing surfaces, reducing smooth operation.

 

Improper Installation

Misalignment between the valve and pipeline, or uneven bolt tightening, may lead to eccentric disc friction and damage to sealing elements.

 

Lack of Regular Maintenance

Neglecting routine cleaning and lubrication can increase operating torque, accelerate seal wear, and shorten the valve’s overall service life.

 

3. Maintenance Tips to Extend Butterfly Valve Lifespan

 

1. Proper Installation as the Foundation

Ensure the valve body is aligned with the pipeline center to avoid eccentric stress.

Use appropriate gaskets between the valve and flange to prevent localized stress.

For actuated butterfly valves, confirm correct travel adjustment to avoid exceeding torque limits.

 

2. Regular Cleaning and Inspection

Periodically remove deposits and debris from the disc surface to prevent seal surface damage.

Check stem packing and seals; replace immediately if signs of aging are detected.

For pipelines carrying particulate-laden media, flush the valve regularly to prevent clogging.

 

3. Lubrication and Corrosion Protection

Apply grease to the stem, bearings, and drive components regularly to maintain smooth operation.

For valves operating in seawater or corrosive environments, select corrosion-resistant coatings or materials such as aluminum bronze or duplex stainless steel.

 

4. Proper Operation and Control 

Avoid rapid or forced operation to prevent disc deformation from impact.

If the valve remains idle for extended periods, keep it partially open and rotate the disc periodically to prevent sticking.

 

5. Periodic Seal Performance Testing

Conduct air-tightness or hydrostatic tests every 6–12 months.

Replace sealing elements promptly if they show signs of aging or loss of elasticity.

 

4. Maintenance Differences for Various Types of Butterfly Valves

 

Soft-Seated Butterfly Valves: Focus on monitoring the aging and compression deformation of rubber or PTFE seals.

Metal Hard-Seated Butterfly Valves: Regularly inspect the contact surfaces between the disc and seat to prevent erosion and wear.

Electric or Pneumatic Butterfly Valves: In addition to valve body maintenance, periodically check actuator signal feedback and torque protection settings.

 

5. Summary

 

The lifespan of a butterfly valve depends not only on product quality but also on proper routine maintenance.

Correct installation, regular lubrication, corrosion protection, and proper operation are key to extending valve life.

A well-maintained butterfly valve can reduce failure rates, lower maintenance costs, and enhance the safety and stability of the system.

 

Q&A – Common Questions

 

Q1: How often should a butterfly valve be maintained?

It is recommended to perform routine inspections every six months, including checking the seals, lubricating the stem, and testing actuator operation.

 

Q2: Will a butterfly valve seize if left unused for a long time?

Yes. Prolonged inactivity can cause the disc and seals to stick together. The valve should be operated periodically or kept in a partially open position.

 

Q3: Which is more durable, soft-seated or metal-seated butterfly valves?

Soft-seated valves offer better sealing performance but are not suitable for high-temperature applications. Metal-seated valves are designed for high-temperature and high-pressure conditions and generally have a longer service life.

 

Q4: Does rust on the valve body affect its performance?

Minor surface rust can be treated with cleaning and anti-rust coatings. However, if corrosion significantly compromises structural strength, the valve should be replaced.