Which backflow device is known not to prevent back pressure?

The proper understanding of backflow prevention devices is crucial for ensuring safe and clean drinking water. The Pressure Vacuum Breaker (PVB) is designed primarily to prevent back siphonage, which occurs when there is a drop in water pressure that can cause contaminated water to be pulled back into the potable water supply. However, it is important to note that PVBs do not provide protection against back pressure, which occurs when pressure in the piping system exceeds the supply pressure.

Back pressure can happen in situations where there are pumps or elevated systems creating pressure greater than the incoming water source. PVBs lack the necessary components to mitigate back pressure, making them insufficient for situations where both back siphonage and back pressure could pose a risk.

In contrast, other devices like the Reduced Pressure Principle Assembly (RPPA) effectively address both concerns of back siphonage and back pressure, making them preferable in complex systems where these risks may arise. Understanding the limitations and appropriate applications of each type of backflow prevention device is critical for maintaining public health standards and regulatory compliance.