1. It can drain successively with stable performance ,large displacement and low air leakage.
2. It can saturate water successively so as to have little condensate water of equipment,rapid heating up and stable heating temperature.
3. Automatic cold air exhaust mechanism with reliable operation ,but without air lock or noise.
The ball float inside the va e body lifts up and down as water level changes so as to close or open the va e viz. both drainage and air resistant.