What is the function of a check valve?

A check valve is a mechanical device that allows fluid to flow in one direction while preventing backflow. It typically operates using a disc or ball that moves away from the seat to permit flow and returns to the seat to block reverse flow. This function is crucial in various applications, such as Plumbing, HVAC systems, and industrial processes, to protect equipment and maintain system efficiency. By preventing backflow, check valves help ensure the proper functioning of pumps and other components in fluid systems.