Gate valves are essential components in industrial applications such as oil, petrochemical, power plants, long-distance pipelines, and shipbuilding. They control the flow of media by moving the gate up or down, switching between open and closed states. However, gate valves can develop leaks over time, posing risks to equipment, safety, and operations. Understanding the structure, working principles, and common causes of leakage can help prevent issues and improve valve performance.
Common Causes of Gate Valve Leakage
1.1 Low Precision of the Wedge Seal Ring
The sealing performance of a gate valve depends on the precision of the wedge seal ring. There are two main types: hard seals (metallic wedge rings) and soft seals (composite graphite rings). If the seal ring’s precision is low or if there are material defects, it can lead to internal leakage.
1.2 Unstable Operating Conditions
During production or operation, fluctuations in pressure and temperature can cause significant stress on the sealing ring. This can lead to deformation over time, enlarging gaps between the seal and the valve body, resulting in internal leaks.
1.3 Poor Maintenance Practices
During valve maintenance, if the sealing surface is not cleaned properly or foreign particles are left behind, they can scratch the sealing surfaces. This can cause grooves or marks, eventually leading to leaks during valve operation.
1.4 Corrosion of the Wedge Seal
Over time, the media flowing through the valve can cause corrosion, especially in harsh environments. If the sealing ring lacks sufficient corrosion resistance or strength, it can degrade, causing leaks. This issue is more common in valves handling corrosive media.
1.5 Inaccurate Actuator Control
Gate valves are often controlled by actuators. If the actuator is not correctly calibrated, it may fail to fully open or close the valve. This incomplete closure can cause internal leakage.
1.6 Valve Body Defects Leading to External Leakage
Defects such as air pockets, slag inclusions, cracks, or sand holes can occur during valve body casting. If these defects are not detected or corrected during manufacturing, they can cause external leaks during operation.
Effective Solutions for Gate Valve Leakage
2.1 Increase Bolt Preload
When internal leakage occurs, the first step is to tighten the valve body’s pressure plate. Increasing the preload on the bolts helps reduce the gap between the wedge seal ring and the valve body, improving the seal. If tightening does not significantly reduce the leakage, more advanced measures should be taken.
2.2 Inject Sealant Through Grease Fitting
For small leaks, sealant can be injected through the grease fitting to temporarily stop the leakage. This provides a short-term solution, but the valve should still be disassembled and repaired as soon as possible.
2.3 Weld to Reinforce the Valve Body
In cases of severe leakage, welding can be used to seal gaps between the valve body, packing box, and pressure plate. This requires disassembling the valve and using proper welding techniques to ensure a secure seal.
2.4 Adjust Actuator Zero Position
If leakage is due to actuator malfunction, the zero position of the actuator should be checked and adjusted. Ensure that the actuator is correctly aligned to fully open and close the valve, preventing incomplete sealing.
2.5 Weld Valve Body or Return for Repair
When the valve body has cracks or other irreparable defects, the best solution is to return the valve to the factory for repair or replacement. If welding is possible, the correct procedure and materials must be used to ensure the repaired valve meets all performance standards.
Why Choose WEIZIDOM Gate Valves?
At WEIZIDOM, we specialize in providing high-quality valve solutions designed to meet the toughest industrial demands. Our gate valves are manufactured using advanced materials and production processes, ensuring long-lasting, leak-free performance in a variety of applications. Whether it’s oil, gas, power, or marine industries, our products are built to prevent leaks, reduce downtime, and ensure reliable operation.
Additionally, we offer expert after-sales services, including regular inspections, customized maintenance plans, and technical support, to help you address any valve issues and maximize the life cycle of your equipment.
Conclusion
Gate valve leaks can be caused by various factors, but understanding these causes and applying the right solutions can help minimize risks. By choosing WEIZIDOM’s reliable, high-performance gate valves, you ensure the safety, efficiency, and longevity of your operations. Our valves are engineered for excellence, backed by expert support to ensure smooth, trouble-free performance in your industrial applications.
