Whenever we turn on the tap to use available water, it arrives in our homes and offices clean, from a regulated pure source, such as a filtration plant. Once we use it and dispose of it, it goes back out of our home through the waste water pipes set up to handle it. But, things happen and there might be times when the outlet becomes blocked off. At this point, backflow can occur, which means that the waste water we just disposed of will try and flow back into the clean water supply. Modern plumbing systems can have a solution built into them to keep this from happening: backflow preventers.
Dangers of Water Contamination
Waste water coming from a home generally consists of flushed material from toilets or washing machines, containing fecal matter and chemicals that could be hazardous to our health should it be allowed to reach the clean water supply. The bacteria that exist in it can cause things like salmonella and E coli to taint the clean water, leading to a host of serious medical conditions in those who then consume that water supply.
Chemicals resident in waste water could potentially taint the clean supply with poisonous materials, leading to serious health hazards the longer it remains there. Backflow preventers are tools installed by a plumber to prevent this from happening by installing them at the sources of clean water entering the home.
How Backflow Preventers Help
Under normal conditions, there should be enough pressure existent in any water line, coming in or going out, that will keep the water flowing in the direction it should be. If the pressure drops due to main breaks, frozen pipes or other plumbing problems, the waste water is no longer flowing in the direction it should, and could easily backflow into the main line.
The anti-backflow valves available to plumbers come in several different types, and all of them work hard to prevent the contaminated water from ever coming into contact with the clean supply. All of them work to block and reverse the path of the water so that it goes to where it should. Among the many types available for this special tool are air gap valves, double check valves, reduced pressure detectors and valves, and lastly, vacuum breakers.
Types of Backflow Preventers Available
Air gap valves are the simplest version of these preventers, and they create a literal gap that the backflow cannot breach. Usually mounted just below a faucet, it blocks the backflow from ever reaching the same level as the faucet intake. Double check valves act as gates to prevent backflow from reaching the water source, and can actually reverse the backflow into the right direction. Vacuum breakers are mounted at least 6 inches above the pipes, and its elbow design uses pressure to keep access to fresh supply blocked.
With reduced pressure backflow preventers, there is a separate chamber between the check valves that keep track of the amount of pressure within the pipes it is connected to. The chamber itself is kept at a pressure lower than the outlet pipe the waste water would be traveling, so that if pressure drops in the outlet pipe, the check valve to the fresh water is kept closed and the reduced pressure keeps the backflow from reaching a level that would breach it.