Backflow preventers overview
Backflow preventers keep dirty water from fouling city water supplies. Backflow valves are required in many cities. They are standard on many sprinkler systems. They ensure that water flows one way through the piping and cannot re-enter the water supply.
The technology
Backflow occurs when water flows from a home or office backwards into the local water main. It may be caused by back-siphonage or by backpressure. Back-siphonage means the city’s water pressure is too low. Water is sucked from the home or office into the water main. Backpressure means water pressure in the home or office is too high. Water forces its way back into the water main.
Backflow preventers use a one-way valve. Most have a ball assembly that lets water flow in one direction only. If the water direction changes, the valve closes and blocks the flow. Foul water is kept out of the main.
Backflow brings non-potable water into the city water main. This can contaminate the local water supply. Drinking water quality may suffer. In some cases, it can be dangerous. (This is a special concern for businesses that use chemicals, such as dry cleaners.) Backflow preventers are installed between the city water main and the home or office water main. It ensures that backflow cannot occur. It is made to withstand differences in the water pressure between the city and private water mains. Many cities require a backflow preventer on any water system, even a lawn sprinkler system. They usually must be tested once a year. This must be done by a certified fire system tester.
A backflow preventer is also called a cross-connection control.
Applications
Most municipalities require a backflow preventer on every sprinkler system. They are needed anywhere there is a concern that non-potable water may enter the city’s water main.
Call Global Fire Prevention today at (845) 781-0117 to learn how we can help protect your building.