WISY 4″ Multifunction Overflow Device

In the event that your rainwater tank is full and additional rain continues to enter, the system would overflow. Therefore a tank overflow outlet pipe of equal or greater volume than any inlet pipe(s), is used to discharge overflow rainwater to grade, storm sewer system, infiltration gallery, or sump/lift chamber. The angled skimming overflow pipe inside the tank will remove floating debris from the water surface. A ball float backflow preventer device is used to prevent backup of water, as well as unwanted debris and vermin from entering the rainwater tank. This device is located inside the rainwater tank.