| The possibility of failure | Why | Elimination method |
| Seal leakage | 1. The butterfly plate, seal with sundry 2. Butterfly plate, seal off match is not straight 3. Exports are equipped with uneven flange bolt stress or pressure 4. Pressure direction according to the requirements of figure2 |
1. Eliminate impurities, clean the valve cavity 2. Is worm gear or electric actuator adjusting screw of the actuator, the valve closed position in order to achieve correct 3. Check with telescopic flange plane and bolt clamping force, should be uniform pressure 4. According to the direction of arrow seal to pressure |
| Two transverse leakage valve | 1. On both sides of the sealing gasket failure 2. Uneven tube flange clamp force without pressure 3. Sealing ring, sealing ring gasket failure |
1. Eliminate impurities, clean the valve cavity 2. Is worm gear or electric actuator adjusting screw of the actuator, the valve closed position in order to achieve correct 3. Check with telescopic flange plane and bolt clamping force, should be uniform pressure 4. According to the direction of arrow seal to pressure |
