What piping arrangement prevents a boiler from draining to a dangerous level?

The Hartford loop is a piping arrangement that helps to prevent a boiler from draining to a dangerous level. This system involves the installation of a loop of pipe that connects the return line of the boiler back to a point above the boiler’s waterline. The purpose of this loop is to ensure that, in the event of a loss of water in the boiler, there is always a continuous path for the water to return to the boiler.

If the water level drops too low, the Hartford loop allows water from the return line to flow back into the boiler, effectively preventing the risk of the boiler operating with insufficient water. This is crucial because running a boiler without adequate water can lead to overheating and potentially catastrophic failure.

While other options like equalizer piping, dry return, and wet return serve specific functions in a piping system, they do not serve the specific purpose of maintaining a safe water level in a boiler as effectively as the Hartford loop does.