RP, DC and PVB backflow assemblies explained.

RP: reduced-pressure principle assembly

An RP assembly uses two check valves with a relief valve between them. It is commonly specified where a higher degree of protection is required. The relief opening must remain visible and properly drained; it should never be enclosed or altered in a way that interferes with discharge or testing.

DC: double-check valve assembly

A DC assembly contains two independently acting check valves. It may be approved for certain lower-hazard applications, depending on the water supplier's cross-connection requirements. A double check is not automatically interchangeable with an RP assembly.

PVB: pressure vacuum breaker

A PVB is designed to protect against backsiphonage in appropriate applications, often irrigation systems. Installation height, orientation and exposure conditions matter. It is not intended to protect against every backpressure condition.

How to identify the assembly at your property

• Read the manufacturer, model and size from the assembly tag or body.
• Photograph the complete assembly, shutoff valves and surrounding piping.
• Keep the water-district notice and due date.
• Confirm the property address and water purveyor.
• Do not assume a failed assembly must be replaced; some failures can be repaired and retested.

Testing, repair and replacement are different services

Backflow testing measures assembly performance and documents the result. Backflow repair addresses failed internal components or related problems when practical. Backflow installation or replacement may be needed when an assembly is damaged, obsolete, improperly configured or not the approved protection for the application.

Your water provider determines its approval and reporting requirements. Scylla can review the notice and assembly information, then coordinate the appropriate next step.