To determine the head pressure, you divide the height of the column in feet by which number?

To determine the head pressure in a fire service context, the correct method involves converting the height of the water column into pressure. This is done using the conversion factor based on the specific weight of water. In the U.S. customary system, the number used is 2.31. This means that for every 2.31 feet in height of a water column, there is a corresponding pressure of 1 psi (pound per square inch).

Using this conversion, if you have a certain height of water measured in feet, dividing that height by 2.31 gives you the pressure exerted by that water column in psi. This relationship is crucial for firefighters and operators to understand as it allows them to calculate the required pressure to overcome the elevation and any friction losses in hoses and other equipment.

The other options typically relate to other measurements or units not applicable to this specific conversion. Therefore, recognizing that 2.31 is the established factor for this specific circumstance confirms its correctness in this scenario.