Cross Connection Practice Exam

To protect the potable water supply linked to a fire sprinkler system using a contaminated auxiliary water supply, what type of backflow preventer should be used?

1. Air Gap Device

2. Double Check Valve Assembly

3. Reduced Pressure Principle Backflow Assembly

4. Pressure Vacuum Breaker Assembly

The correct answer is: Reduced Pressure Principle Backflow Assembly

The correct answer is the Reduced Pressure Principle Backflow Assembly, which is specifically designed to prevent backflow from contaminated sources into a potable water supply. This type of backflow preventer is particularly effective because it has two check valves and a pressure differential relief valve that maintains a reduced pressure zone. This design allows it to handle both backsiphonage and backpressure, making it suitable for protecting against potential contamination that may stem from a fire sprinkler system utilizing an auxiliary water supply. By maintaining a reduced pressure in the system, the Reduced Pressure Principle Backflow Assembly ensures that water cannot flow backward from the contaminated source into the clean water supply, effectively preventing cross connection hazards that could compromise public health. This is especially crucial when dealing with sources of contamination that may be more hazardous. In contrast, other devices, such as an air gap device or double check valve assembly, may not provide the same level of protection against all forms of backflow in scenarios where there is a high risk of contamination, particularly those associated with fire systems. A pressure vacuum breaker assembly is also less effective in scenarios involving constant pressure systems like those typically associated with fire sprinkler systems. Therefore, the Reduced Pressure Principle Backflow Assembly is the most suitable choice for this context.