Boyuan brine valve is a combination of air check valve and liquid level control valve.the working process is as following. 1.the working process starts when floater is drew downwards because of suction.as a result liquid level control valve be opened and brine will be sucked into the resin tank to regenerate resin. 2.When all brine flow into the tank,the air check valve will be closed automatically to prevent air going into the tank. 3.When the process of resin regeneration is complete ,water will be added into tank through the brine valve and air check valve will be opened at the same time. 4.The floater will raise as the water level has reached preset level,liquid level control valve will be triggered to close.as a result,water stop going into the tank. 5.At this point,one working cycle has complete,a new cycle will begin when the floater is again lowered.