1. Bypass valve: the ball valve is generally opened in still water, so the bypass valve is set to level pressure first, that is, both sides are filled with water;
2. Air valve: when filling water, the float will automatically close the valve after removing air; During drainage, air shall be supplemented and the pontoon shall descend automatically;
3. Pressure relief valve: when opening and closing the valve, drain the pressure water between the valve and the sealing cover to avoid wearing the sealing cover;
4. Blowdown valve: discharge the sewage from the lower part of the spherical shell.
