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Outdoot shot of an old water pipe draining water

What is a Backflow Prevention Device?

Backflow is a term that describes the backward flow of a source of water that has been contaminated by sewage that comes back into the home. Although this is an extremely unpleasant phenomenon and a disgusting mess to clean, there are wider implications. The contaminants carried in the backflow represent a significant health hazard that can linger in your home for a long time after the cleanup is finished. The contaminants can include bacteria and viruses that multiple at a tremendous rate, making deep cleaning difficult and necessary. A backflow prevention device is designed to prevent a backflow from occurring altogether, and we will explain how it works in this article. Backflow Prevention Valves These types of devices are designed to prevent the water from flowing in both directions. Once the water has passed through a backflow prevention valve, it cannot flow in a reverse direction and back into your home. There are two main types of backflow prevention valves in common domestic use; they are check valves and double check valves. Check Valves: A simple check valve is designed to automatically prevent the increase in pressure that can cause backflow. This is the most common form of backflow device found in a modern domestic plumbing system. Double Check Valves: A double check valve, as the name would suggest, has a pair of valves. Each valve works independently, and they can substitute for each other in the event of a failure. The two way check valves have a pair of openings that allow the water to enter and exit efficiently. Both types of check valves are pretty small in size, and they have a clean and basic design. There are various sizes available to fit different sizes of pipes, but they all work in the same way. Each check flow valve has an automatic trigger that is not controlled by any external force, and they require no power supply. They work in a similar fashion to an automatic heart valve that will shut if blood attempts to flow back into the chamber. Check Valve Maintenance, Repairs and Replacements Check valves are simple components, but they can suffer from deterioration over time. The formation of cracks on the surface is typically followed by a failure. A good check valve can last 10-20 years in a domestic setting, but in a crowded building, it’s likely to be at the lower end of the time scale. There are a few signs to look out for that your check valve needs replacement, such as water leaks, discolored water, bad tasting water, and unpleasant odors. Repairing the check valve can be a difficult proposition, and it often makes better sense to simply replace the component. Most domestic and commercial plumbing systems are now supplied with at least a single check valve as a backflow prevention device. It’s important to install and maintain these components to improve health and safety. If you’re not sure if you have a backflow prevention device, contact your local certified plumber and ask them to check the health of your plumbing system. By Giovanni Longo President Flood Brothers Plumbing Giovanni Longo is a 3rd generation master plumber who has been practicing his craft and trade in the greater Los Angeles area for well over a decade and a half. A plumbing and hydraulics-engineering innovator, Giovanni’s particular world-class expertise focuses on dealing with challenging sewer system designs as well as resolving complex commercial and residential draining issues. As a certified Flood Mitigation expert, he is also well versed in a wide variety of water damage and remediation solution.