PVB (Pressure Vaccum Breaker) Basics

Also commonly referred to as a Backflow Preventor.

A PVB is a device that allows water to enter through it in one direction, but prevents it from going backwards in the opposite direction.

The PVB is used to keep unsafe water from reversing it’s flow and contaminating the clean water supply.

In New Jersey, it has become a law that EVERY lawn sprinkler system must have a PVB installed. If your sprinkler is 10 years or older, it may have either an AVB (atmospheric vacuum breaker) or nothing installed as it was not mandated. If you currently have a sprinkler system that has either nothing or an AVB, if there are any needed repairs, a PVB MUST be installed in order to bring lawn sprinkler to NJ code.


Why do I need a PVB?

Lawn sprinklers contain a chemical called dihydrogen monoxide. This chemical is known to be lethal if inhaled. OK, so now I will let you in on the name we all use for this chemical…H2O or plain old water. DON’T take everything you see or read on the internet as the Gospel truth. So to answer the question “Why do I need a PVB?”, the answer is that your grass and landscaping have a ton of nasty stuff that if ingested can make you and your family very sick. Does it make sense that you don’t want what is considered to be a health hazard to end up in your drinking water? I mean what’s in that water? Well lets see…Pesticides, Fertilizers, Weed killer and animal waste to name just a few. I personally  DO NOT wish to drink that, thank you very much!


Usually the sprinkler system’s water pressure itself will keep the water from going backwards, but how about those times when the water pressure drops? This occurs more often than we realize. Good examples of what can and do effect water pressure are

  • Using city water and all neighbors are consuming water at same time (watering their lawns, washing cars, topping off the pool, etc.)
  • When the water company has to shut off water to repair a broken pipe.
  • When the fire department is using water to put out a fire.

Now I know most of you are saying ” I only drink bottled spring water so I don’t need a PVB”. But, don’t you cook with tap water? How about your pets, don’t they drink tap water or LOL from the toilet (also tap water). I know I shower in tap water and assume you do also. Now I could go on but I am guessing you get the idea.

So, now you know what a PVB is, why you need one and what may occur if you don’t have one. Hopefully I hae given you enough information to make the correct decision.