An automatic float valve works by allowing liquid within the chamber to lift a float which is linked to a valve which regulates the liquid intake. When the level is low, the float drops and opens the valve, allowing in liquid until the float rises sufficiently to close off the valve again. This is identical in principle to the ballcock valve. This automatic float valve automates the water supply to stock tanks, troughs or barrels for livestock watering. It has a 375 gallons per hour capacity. Our automatic float valves includes expansion brackets and is made of plastic.