New Mexico Pipe Fitter Journeyman (JPF) Practice Exam

What is the function of a check valve?

1. To regulate fluid pressure.

2. To prevent backflow in piping systems.

3. To control the temperature of the fluid.

4. To create a seal under high pressure.

The correct answer is: To prevent backflow in piping systems.

The function of a check valve is to prevent backflow in piping systems. This type of valve allows fluid to flow in one direction only, effectively blocking it from reversing direction when there's a drop in pressure or when the flow stops. This is crucial in various piping applications, as backflow can lead to contamination, system inefficiencies, or damage to the equipment. Check valves rely on the pressure of the fluid to open and close, ensuring that they only permit flow in the intended direction. Other options describe functions that are typically served by different types of valves. Regulating fluid pressure, controlling temperature, and creating seals under high pressure pertain to valves such as pressure relief valves, thermostatic mixing valves, and ball valves, respectively. Each of these serves distinct functions essential for the overall operation and safety of piping systems, but they do not fulfill the essential role of preventing backflow like check valves do.