Have you ever wondered how the water in your daily use remains clean and uncontaminated? A backflow preventer makes it possible to preserve a property’s clean water condition. Not all houses require one, but most types of properties, residential and commercial, install one to ensure their homes’ water quality. Here is what you should know about it.

Understanding a Backflow Preventer: What Is It?

A backflow preventer is a device that prevents undesirable water flow and contamination in the water supply system. It connects the building’s water source and its water distribution system.

From the name itself, this device prevents the reverse flow of clean water to the plumbing fixtures or devices. It also contains the low-pressure flow of contaminated water back to the water source.

A backflow preventer may look like a small box, an attached dome, or a small cylinder. It is usually placed in a secure underground bulkhead, attached to a building’s exterior, or installed at the end of a hose bib in the home or business. The backflow preventer connects to the waterline and has a check valve inside.

How Does It Operate?

Generally, a backflow preventer is designed to release clean water into the water system and not let contaminated water pass through. Only clean water is allowed to flow through the device. Furthermore, it prevents contaminants in the water supply system from contaminating the water source. 

A backflow preventer has a valve that can be opened or closed. When the valve is open, the water from the water supply enters the device. When the valve is closed, the water supply can no longer flow into the device.

The backflow preventer has a sensor that will activate the valve to close it to the water supply if the water pressure inside the water system is low. The valve prevents contaminated water from flowing into the water supply. It also prevents water supply contamination when there is a low-pressure problem.

This device also works when there is excess water on the water supply line. Same as above, the safeguard device automatically closes the valve and prevents contaminated water from flowing into the water supply system when this happens.

The Types of Backflow Prevention Device

There are three types of backflow prevention devices: double check valves, reduced pressure zones, and pressure vacuum breakers.

Doublecheck valves are used in areas where there is slow drainage. They are mostly used for isolating a branch from the rest of the water system for residential and commercial properties.

A reduced pressure zone device is used when there is a high potential cross-connected water distribution system. This device consists of a pressure vacuum breaker and a backflow prevention device. 

The pressure vacuum breaker protects the water system when the pressure is too low, while the backflow prevention takes care of a high-pressure situation.

How to Know You Have a Broken Backflow Valve

You know you have a broken backflow valve when:

  • You Experience Water Leaks: If your water is leaking at the point where the backflow valve is installed, you may have a defective unit or a broken valve. You may also have water coming in out of the pipe. You should immediately contact a plumber to take care of the problem.
  • You Get Discolored Water: When your backflow valve is broken or improperly installed, it can allow the dirty or discolored water that is not treated to flow back to your water supply system.
  • You Get Slow Drainage: When your backflow valve is broken, it cannot let the water flow to the drainage system. This can result in slow or clogged drainage.


A backflow preventer is a safety device installed at the connection point between the water supply and the water system that prevents contaminated water from flowing into the water supply. It also contains the contamination of the clean water source. Should you notice a loose-fitting, leakage, or slow drainage, immediately contact a plumber to make the necessary repairs. Letting the problem linger can result in harmful contamination.

Extreme Irrigation & Lawn is a locally owned and operated sprinkler system installation and repair service provider in Riverside and throughout the Tulsa area. If you need experts in the field, we would love to help. Contact us!