Backflow is the unintended flow of water or other liquids from a potentially polluted source making its way into the potable water supply.
A backflow valve is used to protect water supplies from contamination or pollution.
Only a licensed plumbers with backflow prevention accreditation issued by a registered training organisation can install, inspect, commission and test backflow devices. Hawkesbury River Plumbing Pty Ltd holds this accreditation and would be only too happy to help with you enquiry.