Water enters into a property’s fire protection, plumbing, or irrigation system directly from a main water supply line. However, pressure drops due to a burst pipe, a broken fire hydrant, or other issues, can draw contaminated water backwards into the portable water system, polluting the city’s water supply. Backflow contamination, or stagnant water from the fire sprinkler systems, water carrying pathogens and bacteria from air-conditioning cooling towers, water carrying fertilizers and pesticides from the irrigation system, water containing harmful chemicals from factories, and even sewage water mixing into the portable water system, poses a serious hazard to public health.
We see 32 million cases of acute gastrointestinal illness every year in USA due to contaminated water. This is why portable water supplies should be protected from a possible backflow. Enter backflow preventer valve.
What is a Backflow Preventer valve?
A backflow preventer device is designed to make sure water from the main supply main only flows in one direction: forward. These types of valves are meant to prevent the water in your main water supply lines from flowing in a reverse direction. A backflow preventer allows water from the main line to flow into the property but automatically shut off if the direction of the water is reversed.
Also check: The Importance Of Backflow Testing
Types of Backflow Preventers
Pressure Vacuum Breakers
Generally intended for lawn irrigation, these backflow preventer valves are highly affordable and one of the easiest to install. A pressure vacuum breaker helps to prevent back-siphoning of contaminated water from the sprinkler systems to your portable water supply. This type of a mechanical contraption consists of independent spring-loaded check valves which close when the flow of water stops, test valves, and an independent air inlet valve on the discharge side of the check valve.
The check valve allows water to flow freely and keeps the air inlet closed. However, if the air pressure exceeds the water pressure, the air inlet opens and breaks the suction effect of the low pressure, which prevents the reverse flow of water. Pressure vacuum breakers can be found next to an exterior wall or inside your utility closet.
Double check valve
These valves are best suited for low-hazard situations, such as near fire sprinkler systems, where they prevent water from flowing back into the main supply line. This provides dual protection, since even if one valve fails, the other will prevent backflow. These valves are usually integrated with test cocks that allow technicians to connect test equipment to check the health of a backflow preventer device.
Reduced Pressure Zones
These highly reliable and dependable valves are most commonly installed to prevent antifreeze or corrosion inhibitors from fire protection systems from entering your portable water supply and other high-hazard cross-connection places. In addition to two independent check valves that act as a double-check backflow preventer, these preventer devices also boast a third hydraulically operated differential relief valve, which makes them fail-safe. Should both the check valves fail simultaneously, the relief valve opens to release excess pressure in the chamber by discharging to a drain? These valves provide utmost protection against backsiphonage and backpressure.
When do you need backflow prevention?
While backflow prevention isn’t absolutely necessary for residential properties, but if your home has an irrigation system that cross-connects with the portable water supply, you are required by law to have a backflow preventer installed. Similarly, if you have a culinary water connection that may be used to supply a sprinkler system, you also need a backflow preventer device. But backflow preventer devices are absolutely vital for all commercial plumbing systems. Backflow preventers are generally installed in buildings where clean water cross-connects with large boilers, irrigation systems, and fire suppression systems. Since changes in pressure can cause a backflow problem, it is prudent to have a backflow preventer device installed. Regular maintenance and periodic testing of the backflow prevention device is necessary to prevent malfunctioning.
How to know if your Backflow Device is Malfunctioning?
If the water coming out of your taps is discolored, brown, yellow or even pink in color, or has a rather unpleasant odor or taste, the water may be contaminated due to a backflow. Furthermore, if you see sediment or rust particles floating in the water, it should ring a bell. Similarly, slow or interrupted water flow or uneven water level in different drains are signs of a malfunctioning backflow preventer.
All backflow devices have a lot of internal parts, such as springs, seals, test cocks, shut off valves that may wear and tear with age, and need maintenance and repair. To make sure your backflow preventer keeps functioning as intended, get your device checked and tested annually, even if it seems perfectly alright. Annual testing and repair thwart the chances of a backflow and protect your portable water supply.
