Common Butterfly Valve Faults and Troubleshooting Methods

Introduction

Butterfly valves play a crucial role in industrial fluid control, offering efficient shut-off, flow regulation, and throttling capabilities. However, improper installation, wear, and operational conditions can lead to performance issues. At YAXING VALVE INDUSTRY, we specialize in manufacturing high-quality cast iron butterfly valves and understand the challenges that industries face. This article provides a detailed analysis of common butterfly valve faults and step-by-step troubleshooting methods to help B2B procurement professionals and maintenance engineers maintain optimal valve performance.

Common Butterfly Valve Faults and Causes

1. Valve Leakage (Seat or Flange Leakage)

1.1Potential Causes:

• Foreign particles or deposits on the sealing surfaces

• Improper installation or misalignment of the disc

• Uneven or incorrect torque applied to flange bolts

• Aged, worn, or damaged valve seat material

1.2Troubleshooting Steps:

Inspect and Clean Sealing Surfaces:

• Shut off the pipeline and depressurize the system.

• Open the valve slightly and inspect the seat for debris or scaling.

• Use a soft brush or compressed air to remove particles. If scaling is severe, use an industrial descaling agent compatible with the valve material.

Check Disc Alignment:

• Operate the valve manually to check whether the disc closes symmetrically.

• If the disc appears misaligned, adjust the actuator settings or inspect the stem connection for mechanical faults.

Tighten Flange Bolts Properly:

• Loosen all flange bolts and re-tighten them in a crisscross pattern using a torque wrench to ensure even compression.

• Refer to the manufacturer's torque specifications for your valve size.

Replace Worn Valve Seat:

• If the leakage persists, remove the valve from the pipeline and inspect the seat for wear or deformation.

• If the seat is replaceable, remove it using the appropriate extraction tool and install a new seat compatible with the fluid medium.

2. Packing or Stem Seal Leakage

2.1Potential Causes:

• Worn or aged packing material

• Excessive force applied to the valve stem

• Incorrect packing gland tightening

• Insufficient or improper lubrication

2.2Troubleshooting Steps:

Check Packing Condition and Replace if Necessary:

• If leakage is observed around the stem, isolate the valve from the system.

• Loosen the packing gland bolts and remove the old packing using a packing removal tool.

• Install new packing rings, ensuring that each ring is seated properly and staggered to prevent leakage paths.

Proper Gland Tightening:

• Tighten the packing gland bolts gradually in a cross pattern to ensure even compression.

• Over-tightening can lead to excessive stem friction, so follow manufacturer torque recommendations.

Lubrication and Preventive Measures:

• Use a compatible valve stem lubricant to reduce friction.

• If the stem is visibly worn or corroded, replace it with an OEM-compatible part.

3. Hard-to-Operate or Sticking Disc

3.1Potential Causes:

• Buildup of scale, rust, or debris on the valve disc or seat

• Lack of proper lubrication on the shaft or bearings

• Mechanical damage or bending of the valve shaft

• Over-tightened packing causing excessive friction

3.2Troubleshooting Steps:

Inspect and Remove Debris:

• Open the valve and inspect the disc surface for rust, scale, or deposits.

• Use a non-abrasive cleaning agent or fine sandpaper (600-grit or higher) to remove surface impurities.

Lubricate Moving Parts:

• Apply industrial-grade grease to the shaft bearings and stem to ensure smooth rotation.

• If the valve has a gear operator, check internal lubrication levels and replenish if necessary.

Check for Mechanical Damage:

• Remove the actuator or handle and manually turn the valve stem. If resistance is high, inspect the stem for bending or damage.

• If the valve disc appears to be binding against the seat, adjust the actuator settings or inspect for misalignment in the pipe system.

Adjust Packing Gland if Over-Tightened:

• Loosen the gland bolts slightly and test the operation of the valve. If the valve moves freely after loosening, the packing gland may have been excessively tightened.

4. Actuator Malfunctions (Pneumatic or Electric Operated Valves)

4.1Potential Causes:

• Incorrect air pressure or insufficient power supply

• Solenoid valve blockage or air leaks in pneumatic systems

• Faulty motor wiring in electric actuators

• Worn-out actuator components, such as gears or control modules

4.2Troubleshooting Steps:

Check Power Supply and Control Signals (Electric Actuators):

• Verify that the voltage and current supplied to the actuator match the manufacturer's specifications.

• Inspect the wiring connections for loose terminals or signs of overheating.

• If the actuator fails to respond, test the motor separately using an independent power source.

Inspect and Maintain Pneumatic Components:

• Check the air pressure supplied to the actuator. Low pressure may cause sluggish operation.

• Remove and clean the solenoid valve and air filters to prevent blockages.

• Inspect pneumatic tubing for leaks and tighten connections if necessary.

Lubricate and Replace Worn Actuator Parts:

• If the actuator is slow or unresponsive, inspect internal gears and moving components for excessive wear.

• Apply the recommended lubricant to gear mechanisms or replace damaged parts as needed.

Preventative Maintenance for Butterfly Valves

To ensure long-term reliability, we recommend the following preventative maintenance measures:

Regular Inspections: Conduct visual and functional inspections every 3–6 months, checking for leaks, misalignment, or wear.

Routine Cleaning: Remove buildup of debris, rust, or scale that may affect valve operation.

Proper Lubrication: Apply high-quality lubricants to moving parts, including stems, bearings, and actuator components.

Correct Installation: Ensure that valves are installed according to the manufacturer's guidelines, avoiding excessive pipeline stress or misalignment.

Periodic Actuator Testing: For automated systems, test actuators under no-load and load conditions to verify proper functionality.

When to Seek Professional Assistance

If the valve continues to experience recurring faults despite troubleshooting efforts, consult an experienced technician. YAXING VALVE INDUSTRY provides expert technical support, spare parts, and professional maintenance services to keep your systems running smoothly.

Conclusion

By understanding common butterfly valve faults and applying these detailed troubleshooting methods, maintenance teams and procurement professionals can minimize downtime and extend the operational life of their valves. At YAXING VALVE INDUSTRY, we are committed to delivering high-quality cast iron valves and comprehensive support to ensure the best performance for your industrial applications.

For technical inquiries or custom valve solutions, feel free to contact our expert team.