What is the Difference Between a Backflow Preventer and a Backflow Assembly?

Backflow prevention is a crucial part of protecting clean water supplies from contamination. However, when discussing backflow prevention systems, two terms often come up: backflow preventer and backflow assembly. While they are sometimes used interchangeably, these two terms are not the same.

Understanding the difference is crucial for ensuring your water system complies with local regulations and functions properly. In this blog, we’ll break down the difference between a backflow preventer and a backflow assembly, and their roles in safeguarding your water supply.

What is a Backflow Preventer?

A backflow preventer is any device or mechanism designed to stop the unwanted reversal of water flow. Its primary job is to protect clean, potable water from contamination caused by backpressure or backsiphonage.

Backflow preventers come in various types, ranging from simple air gaps to more complex mechanical devices.

Common Types of Backflow Preventers:

1. Air Gaps – A physical gap between the water source and potential contaminants (e.g., the gap between a faucet and a sink basin). It’s one of the simplest and most reliable forms of backflow prevention.

2. Check Valves – These are basic, one-way valves that prevent water from flowing backward.

3. Vacuum Breakers – Devices that prevent backsiphonage by introducing air into the system when pressure drops.

Key Characteristics of Backflow Preventers:

• Simple in design and function.

• Can be used in low-risk or individual applications.

• Typically not tested or certified annually unless required.

What is a Backflow Assembly?

A backflow assembly, on the other hand, is a more advanced and certified form of backflow prevention. It is a mechanical device made up of multiple components, specifically designed to prevent backflow. Backflow assemblies are required in systems where the risk of contamination is higher, such as commercial or industrial settings.Common Types of

Backflow Assemblies:

1. Double Check Valve Assembly (DCVA) – A unit with two independently operating check valves to prevent both backpressure and backsiphonage.

2. Reduced Pressure Zone Assembly (RPZ) – Offers the highest level of protection, with a pressure relief valve to handle high-risk situations.

3. Pressure Vacuum Breaker Assembly (PVB) – Designed to prevent contamination caused by backsiphonage.

Key Characteristics of Backflow Assemblies:

• Require annual testing by a certified backflow tester to ensure functionality.

• Consist of multiple components, including shutoff valves, test cocks, and check valves.

• Typically used in high-risk applications, such as irrigation systems, chemical plants, or fire suppression systems.

Which One Do You Need?

The choice between a backflow preventer and a backflow assembly depends on your specific water system and its associated risks. For residential or low-risk applications, a basic backflow preventer like an air gap or vacuum breaker may suffice.

However, for high-risk situations, such as commercial irrigation systems or industrial facilities, a certified backflow assembly is not only recommended but often legally required.

Final Thoughts

Understanding the difference between a backflow preventer and a backflow assembly is essential for maintaining a safe and compliant water system. While a backflow preventer is suitable for simple, low-risk scenarios, a backflow assembly is a more robust solution for high-risk applications. Always consult with a Long Beach backflow testing professional or backflow specialist to ensure you have the right protection for your specific needs.

By installing the correct device and adhering to testing requirements, you can safeguard your water supply, avoid contamination, and comply with local regulations. Protecting your water system is not just a legal responsibility—it’s a commitment to health and safety.