Backflow Prevention Practice Exam

What does the check valve number 1 in a reduced pressure principle assembly primarily do?

1. Create a pressure head increase

2. Create a reduction in water pressure

3. Provide water pressure to the relief valve diaphragm

4. Reduce system pressure to the plumbing code limit

The correct answer is: Create a reduction in water pressure

The function of check valve number 1 in a reduced pressure principle assembly is to allow water to flow into the assembly while preventing backflow. This valve is critical in maintaining a distinct difference in pressure within the assembly, which is integral to its operation. When water enters the assembly, check valve number 1 opens, enabling the flow towards the system or the desired area. However, if there is a drop in pressure on the downstream side, the check valve closes to prevent contaminated water from flowing back into the potable water supply. This action effectively ensures that a reduced pressure zone is created, which is essential for backflow prevention. This distinct mechanism therefore illustrates that the check valve primarily contributes to maintaining a reduction in the water pressure within the assembly, which is why this choice is accurate. Other options might describe functions related but do not encapsulate the primary role of check valve number 1 as effectively.