Case
Case
Installation and maintenance：
①Check butterfly valve specification, pressure, temperature and corrosion resistance before installation. All parts should be checked for damage or loosening.
②Butterfly valve can be installed on any angle of the pipe, should be closed installation; welding pipe flange should be the valve seal plate to prevent particles, debris contusion sealing surface, after welding remove the valve, valve sealing surface and pipe cavity cleaning, and then install fixed valve.
③Before installation, clean the sealing surface (both ends sealing surface, butterfly plate sealing surface, seat sealing surface) thoroughly, remove dust and dirt.
④Before installation, the butterfly valve should be empty, the opening and closing should be flexible, the opening and closing position should be in accordance with the pointer indication position.
⑤The butterfly plate must be in the closed position during installation to ensure that the butterfly plate does not collide with the pipe flange.
⑥The opening position should be determined according to the rotation angle of butterfly valve butterfly plate.
⑦Butterfly valve with bypass valve, open bypass valve before opening.
⑧Install butterfly valves according to medium flow arrow.
Troubleshooting and elimination methods：
| Common faults | Common faults | Exclusion methods |
| Sealing surface leakage | Butterfly valve plate, sealing ring with debris | Remove impurities and clean the valve cavity. |
| Butterfly valve plate, seal closed position is not correct. | Adjust the limit screw of the actuator such as worm gear or electric actuator. To reach the valve closing position is correct. | |
| The outlet is equipped with flange bolts with force or not pressed. | Check flange plane and bolt compression force, should be evenly pressed. | |
| The pressure test direction is not as required. | Spinning in arrow direction | |
| Leakage on both ends of valve | Failure of sealing gasket on both sides | Replace sealing gasket. |
| The pressure of the tube flange isuneven or not pressed. | Press flange bolts (uniform force). |
