Backflow Prevention Practice Exam 2025 – 400 Free Practice Questions to Pass the Exam

When both shut-off valves are closed on a reduced pressure principle assembly and test cock 2 is opened, the expected result is that the relief valve will discharge. This happens due to the design and function of the reduced pressure principle assembly, which is intended to protect the potable water supply from contamination.

In this setup, when the shut-off valves are closed, the pressure within the assembly drops. If the pressure in the downstream piping becomes less than the pressure in the area between the two check valves, the relief valve will open to prevent back-siphonage or backflow. It functions as a safeguard to maintain system integrity by allowing any potentially contaminated water to safely discharge rather than entering the potable water supply.

The relief valve discharges to the atmosphere, which is intended to ensure that any negative pressure does not cause backflow into the supply line. This illustrates the importance of relief valves in managing risk within backflow prevention assemblies effectively.