What Is a Backflow Preventer and Why Are They Important?

If your backflow preventer works properly, you’ll never know it’s there. A backflow preventer is a device installed in plumbing systems that prevents contaminated water from flowing back into the main water supply, protecting clean water from potential pollutants or contaminants. When water pressure in the plumbing system gets disrupted, the flow of water reverses direction and threatens to corrupt the water we use, posing significant health risks.

What Are the Different Types of Backflow Preventers?

Pressure Vacuum Breaker (PVB)

A pressure vacuum breaker is a simple and cost-effective backflow preventer commonly used in irrigation systems. These devices employ two critical parts: a check valve and an air inlet valve. When the water pressure drops, the check valve closes to prevent backflow, while the air inlet valve opens to introduce outside air that breaks the vacuum and prevents contamination.

Double Check Valve Assembly (DCVA)

The double-check valve assembly is most often used for commercial and industrial buildings. It’s comprised of two independent check valves that help water flow in just one direction. DCVAs prevent backflow from both backpressure and back siphonage.

Reduced Pressure Zone Assembly (RPZ)

Out of all the backflow preventers, RPZ assemblies are considered the most reliable and robust. They’re made up of two check valves that prevent backflow and are separated by a relief valve that opens to discharge any excess pressure. Because of their immense strength, RPZ assemblies are often utilized in high-risk environments (e.g., hospitals and industrial facilities).

Atmospheric Vacuum Breaker (AVB)

Simple and inexpensive, an atmospheric vacuum breaker is a backflow preventer often found on small, individual fixtures, such as faucets and hose bibs. It consists of a check valve that blocks backflow and an air inlet valve that exposes atmospheric air and breaks the vacuum when necessary. AVBs are effective against back siphonage, although a drawback is that they only offer limited protection against backpressure.

Spill-Resistant Vacuum Breaker (SVB)

The spill-resistant vacuum breaker provides improved protection against backflow from backpressure. Like other backflow preventers, it incorporates a check valve and an air inlet. What makes it unique is its spill-resistant feature, which ensures water continues to flow even if the check valve fails. This design prevents cross-contamination and protects a property’s potable water supply.

Dual Check Valve

A dual check valve is a straightforward, compact backflow preventer comprised of two adjacent check valves. They are commonly employed for low-risk systems like residential homes. While not as complex as the others listed, its dual check valves give baseline protection against backflow from backpressure.

Why Backflow Preventers Are Important

1. They Protect Water Quality
   One of the main reasons backflow preventers are essential is because they safeguard the quality of the potable water supply. Without them, contaminants – including chemicals, pesticides and bacteria – could infiltrate the water we all draw from, resulting in possibly serious health risks. By ensuring that water flows in only one direction, backflow preventers protect us from cross-contamination and maintain the water supply’s integrity.
    
2. Regulations Requirements
   Building codes and regulations mandate backflow preventers to protect public health. Plumbing codes often call for specific types to be installed based on the risk level involved. Those who fail to comply with these regulations risk facing legal consequences and potential liability.
   
   
3. Preserve the System’s Integrity
   Backflow can damage the pipes underneath your home. The reverse flow of water can introduce debris, sediment and other contaminants into the system that can obstruct pipes and valves, resulting in costly repairs or replacements. Backflow preventers help maintain the efficiency and longevity of the water system underneath your feet, limiting the risk of breakdowns and extending its lifespan.
   
   
4. Guarantees Reliable Operation
   Backflow can hinder a water system’s abilities, leading to irregular water pressure, temperature fluctuations and compromised performance. Backflow preventers can ensure a consistent and reliable operation for your home or business, minimizing the chances of service interruptions and maintaining dependable and optimal comfort levels.

Our Arlington Plumbers Can Make Sure Your Backflow Preventer Is Always Performing Properly

The experts at Tom’s Mechanical Inc. can check, fix or replace your backflow preventer to ensure your family continues enjoying clean and safe water. We’re available 24/7 to provide emergency services and get everything back in order as soon as possible. To schedule plumbing services, call (817) 277-4493 or visit us online.