Rhode Island Journeyman Plumber Practice Exam

What is the purpose of a check valve in plumbing systems?

1. To regulate water pressure

2. To prevent backflow

3. To control the flow rate

4. To filter impurities

The correct answer is: To prevent backflow

The purpose of a check valve in plumbing systems is fundamentally to prevent backflow. When water is flowing in a plumbing system, there are instances where the direction of flow could reverse, such as when there is a sudden drop in pressure or a change in the flow dynamics. A check valve addresses this issue by allowing fluid to flow in only one direction through a system, thereby ensuring that, once the water has traveled downstream, it cannot flow back into the source. This function is crucial in maintaining the integrity and safety of the plumbing system, especially when dealing with potential contaminants or pressurized water lines. While water pressure regulation, flow rate control, and filtering impurities are important aspects of plumbing, they are not the primary functions of a check valve. These other mechanisms are managed by different types of devices tailored specifically for those needs—like pressure regulators for water pressure or flow control valves for managing flow rate. The specific design and functionality of the check valve make it a critical component for preventing backflow and safeguarding both the plumbing system and the water supply from contamination.