Backflow prevention devices are devices that are mounted on a pipe that allow water to only flow in one direction. Consider it a one-way gate that permits water from the city's public water supply to flow into your home's pipes but prevents water from flowing back into the main water supply. A backflow preventer valve is a device that prevents water from flowing backward in your main water supply lines. The valve will transmit sanitary water from the main supply pipes to the underground water lines. What is a backflow prevention system? Backflow prevention systems are pipe-mounted devices that only allow water to flow in one way. Moreover, Consider it a one-way ate that enables water from the city's public water system to flow through your home's piping but prevents water from flowing backward into the main supply. The key to preventing backflow is to have a backflow prevention device that is properly installed, maintained, and inspected as part of your culinary water system. If you have a culinary water connection that could be utilized to supply a sprinkler system, you'll need backflow prevention.