If the pressure gauge at the bottom of a 200 ft. standpipe reads 68 psi, what is the static head in feet?

To determine the static head in feet based on the pressure gauge reading, we start by applying the relationship between pressure, height, and head in a fluid system. Specifically, the static head can be calculated using the formula that relates pressure (in psi) to the height of a column of water (in feet).

The pressure at the bottom of a water column can be expressed in terms of height using the equation:

Static Head (in feet) = Pressure (in psi) x 2.31.

Here, the gauge reads 68 psi. To convert this pressure into feet of head, we multiply:

Static Head = 68 psi x 2.31 = 156.68 ft.

Rounding this value gives approximately 157 ft. Thus, when evaluating the choices provided, the answer corresponds with the calculation resulting in 157 ft, confirming it as the correct answer.

Understanding this principle is crucial in water system operations, as it allows operators to interpret pressure readings in terms of the vertical height of water, which is essential for ensuring that adequate pressure is maintained in the system and for making informed decisions about pump performance and system design.