The double check valve DCV backflow preventers are designed to protect portable drinking water in the mains supplies from cross-connections in low risk water applications only, where no hazardous chemicals are present. A RPZ reduced pressure zone valve backflow preventer must be used instead in all other situations, when a DCV is regarded as insufficient protections by plumbing authorities. The RPZ design differs from a DCV by featuring an additional differential release valve as a mechanical fail-safe device. The differential release valve opens and dumps contaminated water to isolate from the mains water supply, if one or two of the check valves fail.
RPZ valves are usually significantly more expensive than the equivalent DCV counterparts, even though they have very similar shapes and appearances. Customers need to check with the local coucil to ensure the correct backflow preventers are used for the jobs.
All Plumbing Online stocks the full size ranges of Watts DCV and RPZ variants of device only or in an assembly with different kits options including unions, ball valves and strainers. Watts has long been the industry benchmark for its quality and value for money. The Watts DCV and RPZ are compatible with other popular brands in Australia such as Zurn, Fabco, Tyco, Wilkins and Conbraco Apollo.
