What is an expansion tank used for in a water system?

An expansion tank plays a crucial role in a water system by accommodating thermal expansion and preventing pressure buildup. When water is heated, it expands, which can lead to increased pressure within the system. An expansion tank allows for this expansion by providing a designated space where the expanded water can go, thus maintaining a safe pressure level in the plumbing system.

This function is vital because excessive pressure can cause strain on pipes and fittings, potentially leading to leaks or even catastrophic failures in the system. The design of the expansion tank typically includes a diaphragm or bladder that separates the water from a cushion of air, which helps manage the pressure fluctuations, ensuring that the system operates efficiently and safely.

In contrast, while storing excess water might seem relevant, it does not capture the primary function of managing pressure caused by thermal expansion. Filtering impurities and enhancing water pressure are roles that pertain to other components in the water treatment or distribution system, not the specific function of an expansion tank.