What does a 'check valve' do?

A check valve is designed specifically to prevent backflow in a piping system. It ensures that fluid can only flow in one direction, which is crucial for maintaining the integrity and functionality of various systems where backflow could lead to contamination or damage. By utilizing a moving component, typically a disc or ball, the check valve automatically closes when the flow reverses, effectively blocking the fluid and stopping it from returning to its source. This is vital in applications such as water supply systems, heating systems, and any other scenario where reverse flow could create safety hazards or operational issues. Thus, the function of a check valve is critical in maintaining the proper direction and pressure of fluid within a system.