Static pressure at the main is 72 psi. Meter loss at design flow is 9 psi, the highest fixture is 26 ft above the meter, and 15 psi residual is required at that fixture. How much pressure is available to overcome friction loss in the piping?

Giải thích

Elevation loss is 26 x 0.433 = 11.26 psi, so 72 - 9 - 11.26 - 15 = 36.7 psi available for friction. The 48.0 psi answer forgets the required residual pressure, and 41.2 psi forgets part of the elevation loss. The 25.5 psi answer subtracts the residual twice or uses a 20 psi flushometer residual that this problem did not specify.