... surface fall, the floater fall too. For normal automatic venting, open bonnet for a slow release of air. A ... , stop discharging. Usually, the bonnet should be open. Also can be matched with shut off valve ... fall, the floater fall too. For normal automatic venting, open bonnet for a slow release of air. A ... , stop discharging. Usually, the bonnet should be open. Also can be matched with shut-off valve ...