Causes of leakage at both ends of butterfly valve:

1. Gaskets on both sides fail.

2. Pipe flange pressure is not uniform or uncompressed.

The solution of leakage at both ends of butterfly valve:

1. Replace the sealing gasket.

2. Tighten the flange bolts evenly.

Causes of butterfly valve sealing surface leakage:

1. There are debris in the butterfly plate and sealing ring of the butterfly valve.

2. The butterfly plate and butterfly valve are improperly sealed.

3. The outlet is equipped with uncompressed or uncompressed flange bolts.

4. Pressure test deviation does not meet requirements.

Key points of handling leakage of sealing surface of butterfly valve:

1. Remove impurities and clean the valve cavity.

2. Adjust limit screw of actuator (e.g. worm gear or electric actuator) to achieve accurate valve closing position.

3. Check the flange plane and bolt pressure, and compress them evenly.

4. Press the arrow bias to maintain rotation.