Journeyman Plumber Practice Exam

A reduced pressure principle assembly is specifically designed to protect the potable water supply from contamination due to backflow. This assembly is particularly important in preventing pollutants from entering the water supply system in various applications, such as irrigation or industrial processes.

The key components of a reduced pressure principle assembly include two check valves and a differential relief valve. The two check valves are arranged in series, which allows for a balanced pressure condition between them. If the pressure drops below a certain level, the differential relief valve allows any potentially contaminated water to be relieved to the atmosphere, thus ensuring that the water supply remains safe and uncontaminated.

This configuration is crucial for the assembly's operation, as the presence of both check valves helps prevent the backflow of non-potable water, while the relief valve serves as a fail-safe mechanism. The combination of these components is what makes the assembly effective in maintaining safe water supply systems.