Cross Connection Practice Exam

What is the required differential pressure across check valve #1 for Reduced Pressure Principle Backflow Assemblies?

1. 2.0 psid

2. 3.0 psid

3. 4.0 psid

4. 5.0 psid

The correct answer is: 3.0 psid

The required differential pressure across check valve #1 for Reduced Pressure Principle Backflow Assemblies is 3.0 psid. This pressure differential is crucial for the proper operation of the assembly, as it ensures that the pressure is maintained on the supply side of the system higher than the pressure in the atmosphere, preventing any backflow of contaminated water into the potable water supply. In Reduced Pressure Principle assemblies, the differential pressure across the first check valve needs to be suitable enough to keep the valve sealed against backflow. When the pressure differential is maintained at this level, it assures that the check valve operates effectively, minimizing the risk of potential contamination. This specific requirement also reflects industry standards for ensuring safety and compliance with plumbing codes, which are critical in protecting public health.