What is the purpose of a check valve?

A check valve serves a critical role in piping systems by allowing fluid to flow in one direction while preventing any backflow. This function is vital in maintaining the efficiency and safety of plumbing and industrial systems, as backflow can lead to contamination, system failures, or equipment damage.

The primary mechanism of a check valve is to utilize pressure differences; when fluid flows in the intended direction, it opens the valve, allowing passage. Conversely, if there’s a reversal in flow, the check valve closes, ensuring that the fluid cannot return. This one-way operation is crucial for systems such as water supply, where preventing backflow protects potable water from potential pollutants.

Understanding this purpose clarifies why the valve's design supports this function, as opposed to allowing bidirectional flow, which would not serve the purpose of preventing backflow. Additionally, the other options—measuring water pressure or removing debris—represent different types of devices used in plumbing and fluid systems that do not encompass the primary function of a check valve.