Backflow Device

A backflow device is also known as an RPZ valve. RPZ stands for Reduced Pressure Zone. This device is installed onto your plumbing system to protect your drinking water and the city water supply from contaminants.

RPZ valves are required when a house or building is equipped with an irrigation system, fire suppression system, pool, fire hose reels. Grease traps. Contaminants can enter an irrigation system from fertilizer or pesticides that are sprayed onto lawns. In the case of a fire suppression system, water sits stagnant or trapped in these systems, which leads to a build-up of bacteria and increased mineral content from the piping system.

If there is a water leak in the house, house water service break, city water main break, hydrant flushing, or hydrant use due to a fire, the water pressure in the house or city water mains can drop lower than the water pressure in the Systems. This can cause water from the Systems to back-up into the drinking water supply. The next time you or a neighbour turns on a faucet for a drink of water, the water received could contain contaminants. Even small fluctuations in city or council water mains that occur due to uneven water use from one neighbourhood to the next can cause drops in pressure large enough to cause a backflow and therefore contamination to occur.

If a drop in council or building water pressure occurs, the RPZ valve will open up, dumping water out rather than allowing the potentially contaminated water to backflow into the water supply. For these reasons, Queensland State Law requires the use of a backflow device as outlined in the As. 3500 National Plumbing and drainage code and Council Local and state plumbing laws must comply with these laws. The law not only requires the use of a backflow device, but that device must be tested annually. Only a licensed plumber with a backflow Certification License can test and certify the proper operation of backflow prevention device valve. Once the device is tested, the certification paperwork is forwarded by the plumber to the relevant council 

For your convenience, Gregors Plumbing & Gas Pty Ltd can provide you with an annual reminder to have your backflow device certified to stay in compliance within your region.