Backflow Preventer Valve
Most of the time water flows “forward” from the water supply system into your home. Backflow is the term used to describe the “backward flow” of water back into the water supply system. In other words, backflow would occur when water from your home “flows back” into the public water supply. Backflow can also be caused when water from a garden hose “flows back” into your home. Backflow can be caused by either back pressure or back-siphonage of your plumbing system. If water flowing backwards contains hazardous chemicals or bacteria, it can cause an unhealthy or dangerous situation.