Backflow Prevention

This website is designed to provide information to people around Australia on Backflow Prevention.
We are your local backflow prevention expert plumbers with a working knowledge of installation, maintenance and approved testing of such devices in your area.

Why are backflow prevention devices used and why do you need backflow prevention devices?
A backflow prevention device, or air gap, is used to protect a potable water supply (drinking water) from pollution or contamination due to a back pressure in the pipe supplying the water.
In mains water supply systems, the mains normally provide a water pressure above 140 kpa; sufficient pressure to enable the water to flow easily from a tap, shower, hand basin and other fixtures.  If water pressure fails, is disrupted or is reduced for any reason, for instance when a water main bursts, pipes freeze or the main is turned off for repair work, water can flow back from your premise to the main supply, thus potentially contaminating that supply.  Fire-fighting or a water truck filling up in the street are other examples of a loss in water supply.  Basically what happens is the back pressure syphons your water, which may contain chemicals or tank water contamination, back into the mains supply, causing sickness or even death to the mains supply customers.

Terminology
Back-siphonage occurs when the supply water pressure drops, causing the flow in a pipe to decrease.  When the supply pressure is lower than the mains or tank supply, the water reverses it’s direction of flow.  The pipe siphons back the liquid into the original supply, thus contaminating the supply.   Contamination can be chemicals from a swimming pool, factory or grey water, not something you would like to drink when the original supply is re-instated.

Backflow means the undesirable reversal of flow of water, gas or a liquid into potable water supply.

Devices can be installed into a water supply pipe to stop drinking water been mixed with non-drinking water.Other potential sources of contaminated water may come from the backflow of things like dishwasher s or washing machines in your home.  Each mixes a chemical with water to clean.  On a bigger scale, factories use tanks to clean parts or cool air conditioners, each have a potential to backflow into the mains water supply.
This non-potable water or non-drinkable water must be prevented from re-entering the drinking water supply. Fire sprinkler systems have water in pipes around the buildings under pressure at all times just in case of fire.  This water in a backflow situation can also become not suitable to drink as years can pass without use.  Stagnate water can contain bacteria.  Similarly if the main water supplying the fire system loses it’s pressure, it may backflow to the mains water (water that has been sitting for years).  Not pleasant water for you to be drinking when it eventually re-enters your normal drinking water supply.  This may cause sickness or death without the appropriate safety backflow device to stop such occurrences from happening.

History of Backflow Prevention

Although the Australian/New Zealand Standard (AS/NZS 3500.1) on Backflow Prevention was published in 2003 it has been in more recent years that the importance of it, as a result of a number of incidents, that backflow prevention has gained more importance.
Certainly since about 2010 backflow prevention has become a more important new regulatory requirement throughout Australia.  The regulations vary slightly from state to state, but essentially all houses and businesses are required to fit backflow prevention devices where there is a risk that any contaminated water can flow back from a premise into the main water supply.  The risk is mainly from industrial properties but houses too can be a risk, for instance where pool water can syphon back into the main water supply.

Our mission is to ensure the protection of your mains water supply

Backflow Prevention is a specialised area of plumbing requiring a Backflow Accreditation licence.   Not all plumbers are experienced or licenced to do backflow prevention.
Backflow Prevention is accredited and has the specialised equipment for the testing of such devices.
Backflow Prevention requires specialised equipment which is tested and calibrated each year to ensure it complies with the regulatory requirements.
Backflow Prevention is represented across Australia by local specially qualified plumbers, working together in each state with mains water authorities, to provide backflow prevention services.

Slogan:              Protecting essential clean water for your better health
Without Backflow Prevention your health is at risk
What is Backflow Prevention
Backflow is a reversal of the normal direction of water flow in a water supply plumbing system whereby contaminates can enter the normal drinking water supply.

Categories of Risk
There are three categories of Risk
High – where the potential failure or absence of backflow prevention may cause death
Medium – where the potential failure or absence of backflow prevention may endanger health
Low – where the potential failure or absence of backflow prevention may cause a nuisance but does not endanger health or cause injury.