Cross Connection Practice Exam

In terms of backflow prevention technology, which device is commonly used to protect against back pressure?

1. Atmospheric Vacuum Breaker

2. Double Check Valve

3. Reduced Pressure Zone Device

4. Air Gap

The correct answer is: Reduced Pressure Zone Device

The Reduced Pressure Zone Device is an effective solution specifically designed to protect against back pressure in water distribution systems. This device consists of two independent check valves with a pressure zone between them, which is maintained at a lower pressure than the system pressure. This design allows the device to prevent backflow caused by back pressure, which can occur when the pressure in the downstream system exceeds that of the supply line, potentially leading to contaminated water entering the potable water supply. This type of backflow preventer is especially important in situations where hazardous substances could be present in the water supply and where the risk of back pressure is significant, such as in industrial applications. The Reduced Pressure Zone Device effectively ensures that any backflow is contained within the device itself, safeguarding the integrity of the potable water supply. The other options, while useful in certain situations, do not provide the same level of protection against back pressure. For instance, an Atmospheric Vacuum Breaker is effective for preventing back siphonage but is not designed to handle back pressure scenarios. Similarly, a Double Check Valve offers moderate protection against back pressure but lacks the additional safeguard provided by the pressure differential in a Reduced Pressure Zone Device. An Air Gap is a physical separation that prevents backflow but does not actively manage pressure different