What is a characteristic of a reduced pressure backflow device?

A reduced pressure backflow device is specifically designed to prevent contamination of potable water systems by ensuring that any potential backflow of contaminated water is effectively managed. One of its key characteristics is the inclusion of a differential pressure relief valve, which plays a critical role in maintaining the proper function of the device.

The differential pressure relief valve allows the device to operate under conditions where there could be a drop in pressure within the system. It discharges excess water if the pressure within the device becomes lower than the upstream pressure, which helps to mitigate the risks of backflow that could lead to contamination.

Understanding the function of the differential pressure relief valve is crucial for ensuring that the plumbing system remains safe and compliant with health standards. This is why the option highlighting the presence of this valve is correct, as it directly aligns with the operational mechanism of a reduced pressure backflow device.