Examples of backflow prevention devises include:
- Air gap
- Atmospheric vacuum breaker (AVB)
- Check valve (usually not a legally approved method of backflow prevention)
- Chemigation valve (primarily used in agriculture)
- Double check valve, or double check valve assembly (DCVA)
- Pressure vacuum breaker assembly (PVB)
- Reduced pressure zone device (RPZ)
- Spill resistant pressure vacuum breaker assembly (SPVB)
- Vacuum Breaker
In Western Australia, approved backflow prevention assemblies are required by law and, in accordance with plumbing or building codes such as Water Services Act 2012 and Water Services Regulations 2013, must be installed by a licensed plumbing contractor such as CH4 Gas & Plumbing.
The following building application types are assessed by the water authority for backflow risk:
- New developments
- Redevelopments of existing facilities
- Changes to any existing water service
- Additions and alterations (includes where no water service applications are included, applicable only if the property has existing meters)
- Multiple residence and/or commercial (includes where no water service applications are included, applicable only if the property has existing meters)
- Any applications that involve a fire service
- Any applications where the minimum water service size applied for is greater than 25mm in size (except fire services, where the backflow advice applies regardless of the service size).
Once your application has been approved you will be informed of the property’s initial backflow risk rating. This can be low, medium or high as per AS/NZS 3500.1:2015. At CH4 Gas & Plumbing we can supply and install the correct backflow devise that meets the level of risk assigned to your property.
A typical backflow assembly has test cocks and shut-off valves, and must be tested when installed, if relocated or repaired, and on a 12-monthly basis. If your devise is due a test, give Jason at CH4 Gas & Plumbing a call on 0401 224 220 – we can test your backflow assembly and submit the required documents to the water authority thus preventing any penalties you would incur due to non-compliance.