The highest fixture in a building is 28 ft above the meter and requires 15 psi residual. Meter loss is 5 psi and calculated friction loss in the piping is 12 psi. What minimum static pressure is needed at the meter?

Explanation

Add every loss to the required residual: 28 x 0.433 = 12.12 psi elevation, plus 5 psi meter, plus 12 psi friction, plus 15 psi residual equals 44.1 psi. The 32.0 psi answer omits the elevation loss, and 40.0 psi rounds the elevation loss down to about 8 psi. The 55.1 psi answer double counts one of the losses and would call for a booster that is not actually needed.