FREE-VALVE floating ball combination air release valves is a barrel shaped valve body, which consists of stainless steel floating balls,Stainless steel filter basket and plug heads.Combination air release valve is installed at the outlet of Pump or in the water supply and distribution pipeline to remove a large amount of accumulated air from the pipeline, so as to improve the efficiency of the water pipe and pumping unit. In case of negative pressure in the pipeline, the valve can quickly suck in air to protect the pipeline from damage caused by negative pressure.