Backflow prevention is critical for protecting your drinking water from contamination. Whether you’re managing a commercial building or an industrial facility, choosing the right backflow prevention device can safeguard your water supply—and your reputation.
At Backflow Inspector, we’ve helped hundreds of property owners across Ontario choose and maintain the correct backflow solutions. In this guide, we’ll break down the most common types of backflow prevention devices, when to use them, and why they matter.
What Is Backflow?
Backflow happens when water flows in the opposite direction from its intended path, potentially carrying contaminants like chemicals, fertilizers, or wastewater into the clean water supply. It can result from backpressure or backsiphonage and poses serious health risks.
Ontario’s Building Code mandates proper backflow prevention for many building types to ensure clean, safe water for all.
Main Types of Backflow Prevention Devices
1. Reduced Pressure Zone (RPZ) Valve
Best for: High-hazard conditions (e.g., medical facilities, chemical plants)
How it works: RPZ valves have two check valves with a pressure-monitored chamber in between. If either check valve fails, the relief valve opens to discharge water and prevent contamination.
Advantages:
Offers the highest level of protection
Detects and relieves pressure failures automatically
Required in severe risk applications
Learn more about our Reduced Pressure Zone Valve installation services
2. Double Check Valve Assembly (DCVA)
Best for: Medium-hazard conditions (e.g., apartment complexes, commercial boilers)
How it works: Contains two check valves in series. If one fails, the other still provides protection.
Advantages:
Suitable for most commercial and institutional buildings
Compact and reliable
Easier to install and maintain than RPZs
3. Pressure Vacuum Breaker (PVB)
Best for: Outdoor irrigation systems
How it works: A spring-loaded poppet valve opens to allow air in when pressure drops, preventing siphonage.
Advantages:
Simple and affordable
Works well for lawn sprinklers
Requires above-ground installation
4. Atmospheric Vacuum Breaker (AVB)
Best for: Single fixture or appliance use (e.g., janitor sinks)
How it works: Uses air pressure to stop water from reversing once flow stops.
Advantages:
Inexpensive
Compact
Easy to install
Limitations:
Can’t be tested or used where continuous pressure is needed
Must be installed downstream of the last valve
How to Choose the Right Device
Choosing the correct device depends on your building type, water usage, and potential hazard level. Factors to consider:
Water system design
Risk of contamination
Regulatory requirements
Maintenance access
A certified backflow professional can perform a hazard assessment and ensure you meet all provincial and municipal codes.
The Importance of Regular Testing
All backflow prevention devices must be tested annually by a certified technician. This ensures:
Continued protection against contamination
Compliance with local regulations
Identification of wear and potential failure
Schedule your backflow preventer testing with our certified team
Trust the Experts at Backflow Inspector
At Backflow Inspector, our certified plumbers specialize in backflow prevention installation, testing, and maintenance for industrial, commercial, institutional, and multi-residential properties. We follow the Ontario Building Code and hold all necessary certifications to keep your water supply safe.
We offer:
10+ years of industry experience
Fully licensed and insured technicians
Transparent pricing and reliable service
Visit backflowinspector.ca to learn more or request a consultation today.
