If you have a sprinkler or irrigation system, you may have seen a brass valve installed above ground near your home. This device is called a pressure vacuum breaker (PVB), and it plays an important role in protecting your home’s water supply.
Like other plumbing components, a PVB can eventually wear out, leak or become damaged. When that happens, replacing the pressure vacuum breaker may be necessary to keep your irrigation system operating properly and help protect your drinking water.
In this video, Jamyn Young, owner of Young Plumbing in Gilbert, Arizona, demonstrates the process of replacing an irrigation PVB and shows some of the tools and techniques professional plumbers use to make the job easier.
What Is a Pressure Vacuum Breaker?
A pressure vacuum breaker, commonly called a PVB, is a type of backflow prevention device used on irrigation systems.
Its job is to help prevent contaminated irrigation water from flowing backward into your home’s clean water supply. Because irrigation water can potentially come into contact with soil, fertilizers, pesticides and other contaminants, backflow prevention is an important part of an irrigation system.
The PVB is typically installed above ground and incorporates a series of valves and an air inlet that help prevent unwanted reverse flow.
When Does an Irrigation PVB Need to Be Replaced?
There are several signs that your pressure vacuum breaker may need attention.
You may notice:
- Water leaking from the PVB
- Constant dripping or spraying
- A damaged or corroded valve
- Problems with your irrigation system maintaining proper water flow
- A PVB that has frozen or been damaged by weather
- Failed backflow testing
- Visible damage to the connected copper or PVC piping
Sometimes a PVB can be repaired with replacement parts. In other cases, replacing the entire pressure vacuum breaker is the better option.
Replacing an Irrigation PVB
Replacing a PVB involves more than simply unscrewing the old valve and installing a new one. The existing piping and fittings may need to be modified to accommodate the replacement valve.
1. Shut Off the Water
The first step is to shut off the water supply feeding the irrigation system.
Once the water is off, open a nearby hose bib or other outlet to release pressure from the line. This makes the system safer to work on and helps prevent water from continuing to flow while the piping is being cut.
2. Remove the Existing Piping
The old piping connected to the PVB can then be cut and removed.
In the video, Young Plumbing uses an automatic pipe cutter and a multi-tool to make clean cuts through the copper piping. Allowing the water to drain before using power tools is an important consideration when working around water.
Once the old piping is removed, the remaining copper can be cleaned and prepared for the new installation.
3. Prepare the Copper Pipe
Before installing new fittings, the copper pipe needs to be properly prepared.
This includes cleaning the pipe and removing burrs from the inside and outside of the cut ends. Cleaning the copper helps ensure that fittings seat properly and creates a clean surface for the connection.
The video demonstrates using abrasive cloth and a Scotch-Brite-style pad to clean and polish the copper.
4. Install the New PVB Fittings
The new pressure vacuum breaker requires threaded adapters that connect the PVB to the plumbing.
Thread sealant and Teflon tape can be used on the threaded connections according to the fitting and manufacturer’s requirements.
One particularly important detail is the direction of water flow.
Look for the arrow on the PVB and make sure it points in the direction the water is supposed to travel. Installing the device backward can prevent it from functioning properly.
5. Measure and Rebuild the Piping
Once the new PVB is positioned, the surrounding piping can be measured and rebuilt.
This may require additional copper pipe and fittings, including 90-degree elbows, to connect the PVB to the existing irrigation line.
Careful measuring is important. The goal is to create a secure connection while keeping the new assembly properly positioned and supported.
Every installation is different, so the exact pipe lengths and fittings required will depend on the existing irrigation system.
6. Connect the Pipes
After the measurements have been taken and the copper has been cut and cleaned, the new sections of pipe and fittings can be assembled.
The video demonstrates using a ProPress system to make the copper connections. One advantage of press fittings is that they can make secure connections without requiring traditional soldering.
In tight spaces, specialized ProPress jaws can also make it possible to reach fittings that would otherwise require additional excavation or modification of the piping.
7. Slowly Turn the Water Back On
Once the new PVB and piping are installed, the water can be turned back on slowly.
The connections should be inspected carefully for leaks, and the irrigation system should be checked to make sure everything is operating correctly.
If the PVB is part of a system subject to local backflow-prevention requirements, appropriate testing should also be completed by a qualified professional.
Should You Replace an Irrigation PVB Yourself?
While some homeowners are comfortable working on irrigation systems, replacing a pressure vacuum breaker involves working with your home’s water supply and, depending on the installation, copper and PVC piping.
A mistake during installation can result in leaks, improper backflow protection or damage to the plumbing system.
If you’re not familiar with plumbing fittings, copper pipe, backflow prevention or the requirements for your local irrigation system, hiring a professional plumber can be the safer choice.
Need Irrigation Valve or PVB Replacement in the East Valley?
A properly functioning irrigation system helps keep your landscaping healthy, but the plumbing components that supply that system need to work correctly, too.
If your pressure vacuum breaker is leaking, damaged or no longer functioning properly, Young Plumbing can help diagnose the problem and determine whether repair or replacement is the best solution.
Young Plumbing provides plumbing services throughout the East Valley, including Gilbert, Chandler, Mesa, Queen Creek and San Tan Valley.
Need help with an irrigation valve or pressure vacuum breaker? If you have an emergency or would like to schedule Young Plumbing to come out for an estimate, call or text 480-549-6711.