What is a backflow preventer?

By Catalogs Editorial Staff

What is a backflow preventor? It's important for safe, clean water!

What is a backflow preventor? It’s important for safe, clean water!

Everyone likes their water to be clean, and thinking about contaminated water coming into your home is something that can make even the bravest of us shudder. The solution to contaminated water will be answered with the question, “What is a backflow preventer?”

Clean drinking water is often something that is taken for granted. We turn on the tap to wash our hands or rinse off a head of lettuce. Sometimes, however, that water isn’t quite as clean as you’d like it to be due to backflow.

What’s backflow?

Back flow is basically what the name implies … when used water flows back to the source of water instead of the waste collection system. This may not sound alarming at first, but consider all the uses of water.

Even simple uses such as doing your laundry or running the dishwasher can have drastic effects if the water flows back to the source.All of the soap and dirt from your dishes and clothes would then flow backwards into the supply–ready for reuse. All of the water would then be contaminated. What about people who use pesticides on their lawn? Something like this could have horrific consequences.

What causes backflow?

Backflow can happen when there is a sudden drop of water pressure, which allows the water to flow backwards; this is the most common type of backflow and is called backsiphonage. What causes a sudden drop in water pressure, you might ask? This can be caused by a broken water main, frozen pipes, or a sudden, unexpected high demand of water supply–such as a fire hydrant being used. Because of the massive amount of water suddenly being used (or leaking out), the water pressure drops dramatically… allowing backsiphonage to take place.

What’s a backflow preventer?

It’s certainly not all bad news, because there’s such a thing as a backflow preventer. This is a device which is in place to prevent all types of backflow. There are many different types of backflow preventers, here are a few of them:

air gap: this is the space between the water outlet and the flood level of a fixture. This allows water to easily flow through a fixture (such as a sink), but doesn’t allow water to flow in the opposite direction.

atmospheric vacuum breaker: this is a device which allows air to enter the system if water pressure drops too low.

pressure vacuum breaker: similar to the atmospheric vacuum breaker, the PVB has a spring loaded poppet, whereas the AVB poppet is “held up” by the water

Keep in mind that backflow preventers are required by law to be put in when a house is built, so if your home is up to code, you have nothing to worry about. Knowing more about backflow preventers can help keep you aware of the state of your household water and what it takes to keep it clean. Backflow preventers are a very important part of our daily lives whether we know it or not. Making sure that your home is up to code with its backflow preventers is an important step to keeping your water safe and clean.

References:
Your drinking water
American Backflow Prevention Association