Important Considerations for Using Double Disc Gate Valves

Double disc gate valves are widely used in various fluid pipeline systems due to their excellent structural design and performance characteristics. Their compact structure, flexible operation, and outstanding sealing capabilities make them an ideal choice for fluid control. To ensure efficient operation and extend the lifespan of double disc gate valves, users should pay special attention to the following aspects.

Pre-Installation Considerations

Proper preparation before installing double disc gate valves is crucial for ensuring optimal valve performance. Adequate preparation not only prevents issues during installation but also significantly prolongs the valve's service life.

1. Pipeline Cleaning

Before installation, thoroughly clean the pipeline system to ensure it is free from impurities, dirt, and foreign objects. Residual solid particles can damage the seat and discs, affecting sealing performance and lifespan.

2. Flow Direction Marking

When installing the valve, adhere to the flow direction markings on the valve to ensure alignment with the pipeline flow. Incorrect installation can lead to backflow, impairing valve performance and potentially posing safety risks.

Installation Process Considerations

Following correct operational steps and standards during the installation of double disc gate valves is key to ensuring normal valve operation. Here are some important considerations to ensure a smooth and safe installation.

1. Connection Stability

Ensure that the valve is securely connected to the pipeline to prevent leaks or disconnections due to improper connections. Use appropriate torque to tighten flange connection bolts for stability and safety.

2. Use of Proper Tools

Do not use the valve's actuator as a lifting point during installation to avoid damaging the actuator and its accessories. Additionally, avoid applying excessive force to prevent structural damage to the valve.

3. Flange Connection

When making flange connections, follow the principle of cross-tightening the flange bolts to ensure even connection. Use a torque wrench to ensure the connection reaches the specified torque value, enhancing sealing effectiveness.

Operational Considerations

Following proper operational protocols during the use of double disc gate valves is crucial for safety and reliability. Here are key considerations.

1. Opening and Closing Speed

Open and close the valve slowly. Rapid operation can cause fluid surges that damage sealing surfaces and internal structures, reducing valve lifespan. Operators should closely observe the fluid state during valve operation and adjust the speed to avoid sudden pressure changes.

2. Switch Position

Choose an appropriate switch position and avoid keeping the valve in a partially open state for extended periods, as this can lead to wear on the sealing surfaces from continuous fluid flow, affecting sealing performance and overall functionality.

3. Stroke Control

During commissioning, ensure that the gap between the limit clamp and the upper and lower limit blocks is maintained at 1.5 to 2 mm. This helps ensure smooth operation of the valve, preventing jamming or failure.

Daily Maintenance Considerations

Regular maintenance and care are essential for ensuring the performance and reliability of double disc gate valves over time. Key daily maintenance considerations include the following aspects.

1. Regular Inspections

Periodically check the valve's sealing performance, operational flexibility, and the tightness of connecting components. Any abnormalities should be addressed promptly to prevent escalation into more serious issues.

2. Fluid Drainage

When the valve will be unused for an extended period, close it and drain the fluid from the pipeline to prevent corrosion and damage. The drained valve should be inspected regularly to ensure it remains dry and free from corrosion.

3. Valve Operation

For valves that have not been used for a long time, regularly operate the handwheel or actuator to prevent scaling or jamming due to inactivity. This measure helps maintain the flexibility and reliability of internal components, ensuring the valve is ready for use.

Fault Handling Considerations

Timely identification and resolution of faults during the use of double disc gate valves are crucial. Here are key fault-handling considerations to ensure normal operation and safety:

1. Stem Seal Leakage

If stem seal leakage occurs, first check if the stem is bent and correct or replace it as needed. Additionally, inspect the gap between the packing gland and the stem to ensure it is adequate to prevent leakage. Timely packing addition is also an important maintenance measure for sealing performance.

2. Seal Gasket Issues

If the seal gasket is leaking, check whether the tightening mechanism is properly adjusted. If the tightening mechanism is not correctly engaged, readjust it. For damaged metal gaskets, replace them with compliant spare parts; for non-metal gaskets, increasing the tightening force can resolve issues and ensure normal operation.

Conclusion

Adhering to the above considerations is essential for ensuring the normal operation and extending the service life of double disc gate valves. Through regular inspections, standardized operations, and timely maintenance, potential faults can be effectively avoided, enhancing overall system efficiency and reliability. This is critical for any industrial application relying on fluid control. Effective management and maintenance will enable double disc gate valves to perform optimally in various applications, providing a solid guarantee for production safety.