Backflow About Backflow - Backflow Brisbane

What is a Backflow
Prevention Device

A backflow device, also known as a backflow prevention device, is a mechanism used to protect potable water supplies from contamination or pollution due to backflow. In water supply systems, water is usually maintained at a significant pressure to allow it to flow from the tap, shower, or other fixture.

Water pressure may fail or be reduced when a water main bursts, pipes freeze, or there is unexpectedly high demand on the water system. Reduced pressure in the pipe could allow contaminated water from the ground, from storage, or from other sources to be drawn into the system.

Backflow prevention devices are designed to block this backward flow into the water supply. They are essential in commercial, industrial, and high residential risk conditions where there’s a chance that a harmful substance might enter the water supply.

How Do They Work?

But how exactly does this happen? These devices rely on specific valves: check valves or two one-way valves. These valves get lined up in a series to prevent backflow from occurring. Think of it as a one-way door—once it’s gone out, there’s no other way for it to come back in.

If any pressure coming back to the water main exceeds that of the route of flow, then the valves close, preventing backflow. So, when the sprinklers go off, the pressure releases upstream, therefore increasing the downstream (toward the water main) pressure. Valves shut, eliminating the possibility of backflow.

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