Butterfly valve failures and eliminations

Malfunction: Leakage at the Sealing Surface

1. Debris may be caught between the butterfly plate and the sealing ring, causing improper sealing.
2. The butterfly plate may not align properly with the sealing seat, leading to gaps and leakage.
3. Flange bolts might not be tightened correctly—either too loose or unevenly compressed.
4. The pressure test was conducted in the wrong direction, which can cause internal stress and damage.

Elimination Methods:

1. Remove any foreign particles and thoroughly clean the interior of the valve.
2. Adjust the actuator's limit screw (such as a worm gear or electric actuator) to ensure the valve closes in the correct position.
3. Inspect the flange surfaces and bolt tightening force. Make sure they are evenly pressed and properly aligned.
4. Perform the pressure test in the direction indicated by the arrow on the valve to avoid incorrect pressure application.

Malfunction: Leakage at Both Ends of the Valve

1. The gaskets on both sides of the valve may be damaged or worn out, leading to leaks.
2. Uneven or insufficient tightening of the pipe flange bolts can result in misalignment and leakage.

Elimination Methods:

1. Replace the damaged or worn-out gaskets with new ones that match the specifications.
2. Tighten the flange bolts evenly using a cross-tightening pattern to ensure uniform pressure across the entire flange surface.

Additional Tips:

Regular maintenance is crucial for preventing such issues. Always inspect the valve before and after operation, and follow the manufacturer's guidelines for installation and testing. If you're unsure about the process, consult a qualified technician to avoid further damage or safety risks.