For what purpose are thermal expansion tanks used?

Thermal expansion tanks are specifically designed to control thermal expansion within a plumbing system. When water is heated, it expands. If this expansion occurs in a closed system, such as a hot water heating system, it can lead to increased pressure within the pipes. This pressure can be harmful, potentially causing leaks or even ruptures.

The thermal expansion tank mitigates this issue by providing an additional space for the expanded water to go. It usually consists of a tank that has an air bladder or diaphragm inside, which allows for the expansion of water while maintaining the overall system pressure within safe limits. This ensures that the plumbing system operates efficiently and safely without risking damage from excess pressure due to thermal expansion.

Understanding this function highlights the importance of thermal expansion tanks in maintaining the integrity of hot water systems, particularly in residential and commercial settings where hot water is frequently used.