Journeyman Plumber ExamPlumbing Code and RegulationsMedium
A journeyman plumber is tasked with installing a backflow prevention device on a non-potable water supply system used for irrigation. According to the Uniform Plumbing Code (UPC), which of the following devices offers the highest level of protection against both backpressure and backsiphonage for this application?
- AAtmospheric Vacuum Breaker (AVB)
- BDouble Check Valve Assembly (DCVA)
- CPressure Vacuum Breaker (PVB)
- DReduced Pressure Principle Backflow Preventer (RPBP)
Show answer & explanationAnswer & explanation
Correct answer: D. Reduced Pressure Principle Backflow Preventer (RPBP)
The Reduced Pressure Principle Backflow Preventer (RPBP) is designed to protect against both backpressure and backsiphonage and is suitable for high hazard applications, making it the most protective option listed for a non-potable irrigation system.
Why the other options are wrong
- A. AVB protects against backsiphonage only and requires downstream air gap, not suitable for continuous pressure or backpressure.
- B. DCVA protects against backpressure and backsiphonage but is typically used for low-to-medium hazard applications, not the highest protection.
- C. PVB protects against backsiphonage only and is not effective against backpressure.
Reduced Pressure Principle Backflow Preventer (RPBP)
A backflow prevention device featuring two independently operating check valves, an automatically operating pressure differential relief valve located between the check valves, and two shutoff valves.
- Protects against both backsiphonage and backpressure.
- Suitable for high-hazard applications.
- Must be installed above ground and requires annual testing.
Memory trick: RPBP: Really Protects Both Pressures!