Massachusetts Plumbers Journeyman Practice Exam

Where should a thermal expansion tank be installed if potential hazards or nuisances may arise due to thermal expansion from water meters or metering devices?

1. Next to the water heater

2. Inside the building foundation

3. Close to the water meter or metering devices

4. On the exterior wall

The correct answer is: Close to the water meter or metering devices

The correct placement of a thermal expansion tank is close to the water meter or metering devices when potential hazards or nuisances may arise due to thermal expansion. This is because thermal expansion tanks are designed to absorb the increased pressure from expanding water, helping to prevent damage to the plumbing system. By installing the tank near the water meter, it can effectively manage the pressure fluctuations that occur especially within the context of a closed water system, where thermal expansion is more pronounced. Positioning it in this way minimizes the pressure that builds up in the system, thereby protecting both the water meter and any downstream fixtures from strain or failure. The other locations, like next to the water heater, may not adequately address specific concerns about the water meter, while being inside the building foundation could complicate access for maintenance. An exterior wall placement also does not provide the same level of protection or functionality, as it may not effectively manage thermal expansion impacts on the water meter itself.