A sudden and unexpected drop in water pressure normally causes backflow. Some of the causes for this can be water main bursts, pipes freezes or unexpectedly high demand on your water system. This automatically creates a negative pressure in the water supply system. When a backflow occurs, reduced pressure may allow contaminated water from the ground, storage or other sources to enter the plumbing system. One of the biggest concerns is that this allows drinking water to be contaminated via a cross-connection of the water
A properly installed and maintained backflow device will ensure water flows safely by automatically trapping water that begins to flow in the wrong or opposite direction. This prevents water from a property being drawn back into the main drinking water supply and causing bad cross-connection.
The risk ratings of a home or building will determine what type of backflow device will need to be installed. Homes and buildings are classed as very low, medium or very high risk. A professional plumber from Local Plumber Brisbane who is an accredited plumber can confirm the risk rating of your property.
A typical backflow assembly unit will have test cocks and shut off valves. Backflow devices must be thoroughly tested when they are installed, relocated or carefully repaired. Backflow devices must also be tested annually to ensure they are in proper working order.
Brisbane Water States the following about backflow:
Each backflow prevention containment device must be tested on an annual basis. This is a condition of connection to the water supply. It means that the device is maintained and continues to operate effectively. The annual test will ensure the drinking water supply is protected from backflow.
If a device is defective or faulty, it may do the following:
- not prevent a contaminated source entering the drinking the water supply
- cause water to be wasted through the leaking devices
- impact on the water pressure supplying water your property
A backflow prevention accredited licensed plumber will need to test all of your devices. After testing your devices your licensed plumber will submit his report within 2 days on the Brisbane water website stating if the device is installed correctly and if it has passed or failed the test. The plumber Brisbane will give you a copy of the Backflow Prevention Device Inspection and Maintenance Report. If a valve fails the test and is not repaired or replaced Brisbane water can disconnect you from the main water supply.
