Parallel Double Disc Gate Valve Pressure Test Process

The pressure testing of parallel double disc gate valves is a critical procedure to ensure the valve's quality and reliability. Through a scientific and rigorous testing process, it is possible to verify the valve's pressure-bearing capacity, sealing performance, and service life under various operational conditions. By following standardized testing steps, the gate valve can meet design specifications and maintain excellent performance during operation, ensuring the safety and stability of industrial production.

Preliminary Inspection and Preparation

Before conducting the pressure test, a comprehensive and detailed inspection of the parallel double disc gate valve is required. This step ensures that the valve is in optimal condition, preventing any defects from impacting the test results.

Inspection items include:

Valve Appearance: Check for visible damage, cracks, or corrosion on the valve body.
Valve Body and Cover: Inspect for cracks, deformation, or any mechanical damage.
Discs and Seals: Ensure that the gate discs are free from wear or cracks, and that the seals are intact with no signs of aging, damage, or failure.
Connection Parts: Inspect the flanges, bolts, and other connection parts to ensure they are securely fastened and free from any loosening risks.
Only after meeting all technical requirements should the pressure test proceed.

Determining Test Parameters

To ensure the effectiveness of the pressure test, the test pressure and duration must be determined based on the gate valve's technical specifications, usage environment, and operational pressure requirements.

Common test parameters include:

Test Pressure: Typically, the test pressure should be set at 1.5 times the gate valve's working pressure to evaluate its maximum pressure capacity and sealing performance. The pressure range may vary depending on the valve type and specific model.
Test Duration: The duration of the test directly impacts the valve's sealing ability. The test should last long enough to ensure that the valve does not leak or experience any structural changes under prolonged pressure. Typically, the test lasts between 15 and 30 minutes, but this can be adjusted in special circumstances.
Proper pressure and time settings will effectively test the valve's performance while avoiding potential damage from excessive pressure or overly long durations.

Pressure Testing Process

During the pressure test, precise and professional equipment is required to ensure the accuracy and reliability of the test. Commonly used equipment includes pressure gauges, pressure pumps, and leak detection devices.

The specific steps are as follows:

Connect Testing Equipment: First, connect the pressure pump to the valve's inlet, ensuring all joints are sealed to prevent leakage.
Gradually Increase Pressure: Start the pressure pump and slowly increase the pressure to the preset value. The pressure should be raised steadily to avoid sudden impacts that could negatively affect the gate valve.
Monitor the Test: Once the test pressure is reached, continuously monitor the valve's performance, especially for any leaks, deformation, or other abnormal conditions. At the same time, ensure the pressure gauge maintains the test pressure within the preset range.
Leak Detection: Use specialized tools to check all connection points and sealing areas for any leaks.
End of Test: After the designated test duration, gradually release the pressure to prevent sudden pressure drops that could impact the valve.

Test Result Evaluation and Action

After the pressure test, a comprehensive evaluation of the results is necessary. If the gate valve performs stably under high pressure without leakage, deformation, or other abnormalities, it indicates that the valve has good pressure-bearing and sealing performance.

Evaluation standards include:
Pressure Capacity: Whether the gate valve can withstand the pressure as per the design requirements.
Sealing Performance: Whether the valve's sealing is intact under high pressure and if any leaks are detected.
Structural Integrity: Whether the valve retains its original shape without deformation or damage during the test.

If any issues, such as leaks, deformation, or failure to operate properly, are found, testing should be stopped immediately. The cause of the issue should be identified, and the relevant parts should be repaired or replaced. If necessary, the pressure test should be repeated until the gate valve meets quality standards.

Post-Test Inspection and Maintenance

After completing the pressure test and confirming that the gate valve meets performance standards, the following actions should be taken.

Cleaning: Check the valve's interior for any residual moisture or impurities to ensure it is clean and free from contamination.
Lubrication: Inspect seals and moving parts to determine if lubrication is needed to ensure smooth operation.
Storage or Installation: Depending on usage requirements, the tested valve should be either stored appropriately or installed directly in the production system.

Conclusion

The pressure testing of parallel double disc gate valves is a key procedure for ensuring their quality and reliability. By following a strict testing process, the valve's pressure-bearing and sealing performance can be effectively evaluated, guaranteeing long-term stable operation and supporting the safety and efficient functioning of industrial production. Through comprehensive inspections, scientifically determined parameters, precise operations, and strict evaluations, the gate valve can demonstrate excellent performance in various complex environments.