1. Bypass valve: The ball valve is generally opened by static water, so the bypass valve is first pressed, that is, both sides are filled with water;
2. Air valve: When filling the water, remove the air and take the float to close the valve; when draining, replenish the air and the float will descend by itself;
3. Pressure relief valve: When opening and closing the valve, the pressure water between the valve and the sealing cover is excluded to avoid wearing the sealing cover;
4. Drainage valve: discharges the sewage in the lower part of the ball housing.
