High Performance Butterfly Valves: Operation and Troubleshooting

High-performance butterfly valves are widely used in water conduits and industrial systems, renowned for their exceptional pressure resistance and enduring service life, making them crucial for regulation and flow control. Compared to traditional centerline butterfly valves, high-performance models excel in stability, especially in large-diameter applications where they consume less material and offer better cost-effectiveness. Their unique double offset design not only effectively reduces flow resistance but also significantly lowers maintenance costs, although its benefits are relatively limited in applications smaller than DN200. Moving forward, we will explore the structure and working principle of high-performance butterfly valves and analyze common faults and their remedies.

Structure and Working Principle

 
High-performance butterfly valves have been improved based on single-offset butterfly valves, with the key feature being that the valve stem is offset from both the center of the disc and the center of the valve body. This double offset design allows the disc to quickly detach from the seat when the valve opens, reducing unnecessary compression and scraping between the disc and seat. This not only significantly reduces the opening resistance but also decreases wear, thereby extending the service life of the seat.
Furthermore, the double offset design permits the use of metal seats, which is particularly important for high-temperature applications. The disc is installed in the diameter direction of the pipeline and rotates around the axis within the cylindrical channel of the valve body, with a rotation angle range of 0° to 90°. This design enables high-performance butterfly valves to effectively regulate flow; when rotated to 90°, the valve reaches its maximum opening, achieving precise flow control.

Common Faults and Remedies of High-Performance Butterfly Valves

 
Various faults may be encountered during the use of high-performance butterfly valves. Understanding the causes and remedies of these faults helps maintain the valve's efficient operation and extends its service life. Below are some common faults and their corresponding remedies.

1. Valve Failure to Change Direction

 
When a high-performance butterfly valve fails to change direction or moves slowly, it typically affects the system's operational efficiency and control precision. The following are common causes and detailed remedies.

Main Causes

 
Poor lubrication: Insufficient lubricating oil or malfunctioning lubrication systems.
Spring issues: Springs may be stuck, damaged, or have lost their elasticity.
Blockage by impurities: Grease or impurities may have jammed the sliding parts, hindering movement.

Basic Remedies

 
Inspect the lubrication system: Ensure that the oil mist generator is functioning properly and check if the viscosity of the lubricating oil is suitable for the operating conditions. Replace the lubricating oil with an appropriate one if it is too thick or too thin.
Cleaning and maintenance: Regularly clean the sliding parts of the valve to remove grease and impurities, ensuring smooth operation. Check the condition of the springs and replace damaged ones when necessary.
Lubricating oil replacement: Replace the lubricating oil promptly if it is found to be degraded or insufficient and inspect other parts of the lubrication system.

2. Wear of the Disc Seal, Stem, and Seat Damage

 
When high-performance butterfly valves exhibit wear of the disc seal, stem, and seat damage, it usually leads to gas leakage, slow valve action, or failure to operate properly. The following are possible causes and detailed remedies.

Main Causes

 
Prolonged use: Long-term use can cause wear of the seal, stem, and seat, potentially leading to gas leakage and slow valve action.
Improper operation: Excessive mechanical impact or improper use during operation may occur.

Key Remedies

 
Replace worn parts: Regularly inspect the wear of the seal, stem, and seat, and replace worn or damaged parts in a timely manner.
Check operating conditions: Ensure that valve operation complies with design specifications to avoid excessive wear caused by improper operation.

3. Solenoid Pilot Valve Failure

 
The solenoid pilot valve plays a crucial control role in the high-performance butterfly valve system. When a solenoid pilot valve fails, the valve may not change direction properly or exhibit other issues. The following are common faults and their remedies.

Main Causes

 
Blockage by debris: The intake and exhaust ports may be blocked by oil sludge or debris, preventing the valve from changing direction properly.
Leakage: The sealing performance of the pilot valve may have declined, leading to gas leakage.
Electrical faults: Including control circuit faults or solenoid coil faults, which may cause abnormal valve action.

Common Remedies

 
Cleaning and inspection: Clean the solenoid pilot valve and its movable core to remove oil sludge and impurities. Check the valve body's sealing to ensure there are no leaks.
Electrical inspection: Solenoid coil inspection: Measure the voltage of the coil to confirm it meets the rated value. If the voltage is too low, check the power supply and associated limit switch circuit in the control circuit.
Terminal inspection: Check if the terminals of the solenoid coil are loose or have poor contact. After unplugging, measure the resistance of the coil. If the resistance is abnormal, the solenoid coil should be replaced.
Repair or replacement: If cleaning and inspection do not resolve the issue, repair or replacement of the solenoid pilot valve may be necessary.

Summary

 
High-performance butterfly valves are essential for flow regulation and control in modern industries. Their double offset design boosts pressure resistance and service life, reduces flow resistance, and cuts maintenance costs. While they may have limitations in small-diameter applications, their benefits in large-diameter and high-temperature settings outweigh these drawbacks. Regular maintenance and prompt resolution of issues like directional problems, seal wear, and solenoid pilot valve failures are vital for optimal performance. As technology advances, these valves will continue to play a crucial role in complex fluid control systems, with expanding applications and enhanced performance.