Which device is commonly used to control thermal expansion problems?

Thermal expansion tanks are specifically designed to address the issue of thermal expansion in water systems. When water is heated, it expands, and this increase in volume can lead to excessive pressure in the plumbing system. A thermal expansion tank provides a space for the expanded water to go, thereby alleviating the increase in pressure and preventing potential damage to pipes and fixtures.

In residential water heating systems, when the water in the heater heats up, it expands significantly. Without a thermal expansion tank to accommodate this expansion, the pressure in the system can build up to dangerous levels, which might lead to leaks, bursts, or damage to the water heater itself. By incorporating a thermal expansion tank, the excess pressure is managed, ensuring the safety and longevity of the plumbing system.

Other devices mentioned serve different purposes. For example, a pressure relief valve is intended to release excess pressure but does not specifically accommodate thermal expansion. Atmospheric vacuum breakers are designed to prevent back siphonage and maintain a proper water supply with no connection to thermal expansion. A backflow preventer is aimed at preventing contamination of the potable water supply and does not manage pressure due to thermal expansion. Thus, thermal expansion tanks are the appropriate choice for controlling thermal expansion problems.