What does an expansion tank do in piping systems?

An expansion tank plays a crucial role in piping systems by absorbing changes in water volume that occur due to temperature fluctuations. When water is heated, it expands, which can create excessive pressure within the piping system. The expansion tank provides a space for this expanded water to flow into, thereby preventing potential damage to the pipes, valves, and other components. This mechanism helps maintain a balanced pressure in the system, ensuring it operates safely and efficiently.

While filtering impurities, increasing water pressure, or serving as a backup supply are important functions in various plumbing contexts, they do not pertain to the specific purpose of an expansion tank. The primary focus of the expansion tank is to accommodate the variations in water volume and maintain system integrity rather than address these other functions.