What role do check valves play in plumbing systems?

Check valves are essential components in plumbing systems primarily designed to prevent backflow of water. Their main function is to allow water to flow in only one direction, effectively blocking any reverse flow that could occur due to pressure fluctuations or changes in the system. This is crucial for protecting the supply lines from contamination, as backflow can introduce pollutants into the clean water supply.

By maintaining a one-way flow, check valves ensure the integrity and safety of the plumbing system, which is vital for public health and adhering to plumbing codes. They are widely used in various applications, from residential plumbing to industrial systems, particularly in areas where backflow could pose significant risks.