Are atmospheric type vacuum breakers and pressure vacuum breaker assemblies effective for protection against backpressure?

Atmospheric type vacuum breakers and pressure vacuum breaker assemblies are specifically designed to protect against backflow caused by back siphonage, not backpressure. Backpressure can occur when the pressure in a downstream system exceeds the pressure in the water supply, which could force contaminated water back into the potable water supply.

Atmospheric vacuum breakers operate by allowing air to enter the system to prevent a vacuum from forming; however, they do not prevent backpressure. Similarly, pressure vacuum breakers also rely on atmospheric pressure to maintain flow direction but are not designed to handle scenarios where backpressure is present.

Both types of devices are limited in their protective capabilities and are thus considered ineffective in scenarios where backpressure is a concern. Consequently, stating that they are effective for protection against backpressure is incorrect, affirming that the answer is accurately identified as false.