1. The pontoon of the exhaust valve is made of low density PPR and composite material, which will not deform even if it is soaked in high temperature water for a long time. It will not make the buoy difficult to move.

2. The pontoon lever is made of hard plastic, and the connection between the lever and the pontoon and the support is movable, so it will not rust during long-term operation, resulting in water leakage due to system failure.

3. The sealing end face of the lever is supported by spring, which can expand and contract with the movement of the lever to ensure the sealing without exhaust.