Function classification:

1. Bypass valve: The ball valve is generally opened for still water, so the bypass valve is set to be flat pressure first, that is, the two sides are filled with water;
2. Air valve: when filling with water, the buoy will automatically close the valve when the air is removed; when draining, the buoy will drop by itself for supplementing air;
3. Pressure relief valve: When opening and closing the valve, remove the pressure water between the valve and the sealing cover, so as not to wear the sealing cover;
4. Sewage valve: discharge the sewage in the lower part of the spherical shell.

Transmission classification:

1. Pneumatic ball valve
2. Electric ball valve
3. Hydraulic ball valve
4. Gas-hydraulic ball valve
5. Electro-hydraulic ball valve
6. Turbine drive ball valve