A 101 on backflow prevention devices

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Backflows are among the most annoying, most inconvenient and the most harmful of all plumbing emergencies that you have to watch out for. This article features the importance of installing backflow prevention devices and other related information that you should know as a homeowner.

Have you ever experienced water contamination in your home due to wastewater reversal? I hope not. Backflows are among the most annoying, most inconvenient and the most harmful of all plumbing emergencies that you have to watch out for. You see, while we may get totally irritated at not being able to use our supposedly potable drinking water, we should not forget that ingestion is the bigger problem. What if a loved one accidentally drinks that toxic water? What if it’s your kid who intakes that foul-smelling, bacteria infested liquid? Backflows may cause more harm than what you thought it could. And that it is why we need backflow prevention devices.

What causes backflows?
Backflows are the reversal of the unfavorable substances in your drainage system including gasses, sewage, industrial wastes and other harmful liquids and / or elements. They result from the cross-connection in your plumbing system specifically when pressure changes. For example, you might be doing some gardening and have a bucket of herbicide ready for your plants. You decide to water your greens and while you are doing the task, your spouse calls you and because you’re in a hurry to get inside, you accidentally put the end of the hose into the bucket. You forget that it’s not supposed to be put in there. The hose creates some kind of suction effect and siphons some herbicide into the system. The liquid then travels from the tube into your tap and straight to your water lines, contaminating your clean water. That’s one example of a backflow occurrence. Now what you have to remember is that since there are a lot of cross-connections in your plumbing, backflows may actually happen anytime --- if you don’t have a preventer installed.

What are backflow prevention devices?
Backflow prevention devices protect your clean water lines from contamination that result from the reversal of undesirable liquid and other substances into the system. Its main function is to maintain a specific amount of pressure so that in case of a plumbing emergency such as pipe bursting or freezing, wastewater won’t travel back to your potable water supplies. It most cases, backflow preventers create air gaps in the system to accomplish what they are tasked to do. Air gaps are open spaces found between a valve or fixture and a place where water can accumulate or pool. Because of the air gap, pressure is maintained and soiled water is restricted from backing up.

Are there types of backflow preventers?
Yes, there are several types of backflow preventers. We have the pressure vacuum breaker or PVB; the double check assembly or DCA; the reduced pressure zone or RPZ and the atmospheric vacuum breaker or AVB. The first three are installed just right after the isolation valve while the last one (AVB) is installed after the zone control valve, specifically on each of the sprinkler system zone.