How to Install a Pressure Vacuum Breaker on Your Irrigation System


A pressure vacuum breaker is one of the essential irrigation equipment that protects against the backflow of water to your home’s water storage. Water backflow or back siphoning is a phenomenon that occurs when water pressure falls in the pipe. In such situations, it starts to flow in the opposite direction due to the pressure difference.

As when the water starts to flow backward, it takes back all sand debris and other contamination along with it making your freshwater supply (drinking water) unfit for use.

You can save a lot of money by installing a pressure vacuum breaker by yourself as opposed to getting it installed from a professional.

The article features all the necessary steps to install a pressure vacuum breaker on your irrigation system.

Pressure Vacuum Breaker

Make Space to Install the Vacuum Pressure Breaker

Most of the irrigation system contains a pressure vacuum breaker, which is usually located on the outdoors next to an enclosed attached box in the ground. It is can also be installed inside the house, which is generally located under the basement near the water shut-off switch for the irrigation system.

No matter where you chose to install the vacuum pressure breaker, it is essential for you to create a flexible space for it. Make sure that you dig up a reasonable area between the main sprinkler shut-off and the valve.

In case you don’t have a shut-off valve, it would be better to install one as it works effectively to control the flow of water. 

You would only need to dig a 12-18 inches worth of space for the installation of the vacuum pressure breaker.

Ensure the Size of the PVB

Non-alignment of the pipes with the pressure-vacuum breaker is one of the common mistakes that people make while selecting the size of the PVB. People often downsize the pipe with a valve smaller than required. It can create various water volume problems in your sprinkler system.

As when you use smaller pipes, the flow of water is restricted and also creates a difference of pressure it. Also, it can compromise the structure of the pipe and damage the valve.

For you to maintain constant pressure throughout the sprinkler system, you need to ensure that the pressure-vacuum breaker valve is of the same size as that of the pipe.

Make a List of All the Essential Parts for the Installation

Now, before you begin with the installation of the various parts of the PVB, it would be great if you made a list of all the essential elements beforehand. Not only will it help you to keep a count on all the vital parts that’ll be needed at the time of installation, but it will serve as a useful backup at the times of repairs in the future. 

So, if you made a list of essential PVB parts, it would look like adapters, pipe, glue, plumber’s tape, and many other things.   

Note:  The fact you won’t necessarily need it for the winters, you might need to disassemble it. Keeping a list of inventory will help you to install it in the summers again.  

Use Plumber’s Tape for the Adapters

While installing the vacuum valve, you might need to check the area that you will need between the inlet and outlet with a PVC elbow pointing down from the outlet. To check the area, you can use a plumber’s tape to the adapters to make it tighter into the pressure-vacuum valve.

Make sure that you have a reasonable amount of area for the installation. It will also give you an idea of what amount of space that you might need if you are running short of spaces in the first place.

It is crucial for you to have a feasible plan before you cut the existing pipe for the installation.

Mark the PVC Main Line

Before you cut the main water line of the pressure vacuum breaker, you must make a precise calculation of the length of the pipe. It would be best if you mark a different section of the pipes from where it needs to be cut and label them based on the fittings. It will prevent you from getting confused between various pieces at the time of installation.

Ensure that the valve that you are using is placed at least 12 inches above the highest outlet. Also, make sure that you measure it from the center of the middle ball valve.

Measure and Cut the Pipe In Proper Sections

As when you cut a different length of pipes into several other smaller sections for the installation of a vacuum breaker, make sure that you place it at a precise height. It will help in the seamless sync between the pipe and the valve.

Note: It would be best if you leave it a little longer than the required. As if you feel the need to cut it shorter later, you won’t run short of pipe.   

Use a Level to Ensure that it is Well Positioned

Now, you have assembled all the necessary components in appropriate sizes, start with the things that need to be done first and foremost. It includes the gluing the pressure-vacuum breaker right angled elbows onto the pipe in the soil with the pipe risers.

Measure and Install All the Unions

Once you are done installing the risers to the ground, take proper measurements, and establish all the unions. Take the utmost care in measuring the length of small pieces of the pipe as these will be attached between the PVB and the outlet 90-degree elbow.

Now, cut the smaller pipes and glue them to their respective places. Make sure you also glue the 90-degree elbow to the PVB adapter.

Glue-All the Pieces Together

One of the essential steps of the installation of a PVB is the precise alignment of the different pieces of the pipes using glue. A slight miscalculation in the arrangement of the pipes may result in the malfunctioned pressure vacuum system that can be caused by the possible leakage of the water.

Make sure that you glue vertical pieces straight down on the fittings. One easy way to level the valves is dry-fitting of the parts first, but do not forget to fix the joints. The use of colorful glue would be a suitable option for you to categorize between glued and non-glued joints.     

Note: While joining the joints of the pipe, make sure that you install the PVB in the right direction. You can follow the sign of the flow of the water highlighted on the PVB to avoid the mistake.

Leave the Joints to Dry-Off

After you glued every single joint to its place, it is time for you to leave it aside for a specific amount of time, as mentioned at the backside of the glue. Once it’s dried-out, check if everything works correctly or not. 

Before testing it for the first time, make sure that both the valves are turned off on the PVB. Now, slowly & gradually turn on the main sprinkler valve. Turn on the PVB valve, but make sure that you do so one at a time. Check thoroughly for any possible leaks. 


The fact that people have the same water system for various purposes, there is always a risk of water pollution through cross-connections. Installing a pressure vacuum breaker is a great safety device to protect your irrigation equipment. Make sure you go through all the steps before you install a PVB system by yourself.


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