What is the approximate gpm when a 1 1/4-inch solid stream nozzle operates at 50 psi?

• A. 150 gpm
• B. 256 gpm
• C. 328 gpm
• D. 400 gpm

Answer: (C)

To determine the approximate gallons per minute (gpm) that a 1 1/4-inch solid stream nozzle operates at 50 psi, it is essential to consider the relationship between nozzle size, pressure, and flow rate.

The flow rate for a nozzle can be estimated using the formula:

[ \text{gpm} = \frac{29.7 \times d^2 \times \sqrt{P}}{\text{C}} ]

where:

• ( d ) is the diameter of the nozzle in inches,

• ( P ) is the pressure in psi,

• ( C ) is a constant that can vary but typically is assumed to be 1 for solid stream nozzles.

For a 1 1/4-inch nozzle, the diameter, ( d ), is 1.25 inches. When applying the given formula:

[ \text{gpm} = 29.7 \times (1.25)^2 \times \sqrt{50} ]

First, calculate ( (1.25)^2 = 1.5625 ). The square root of 50 is approximately 7.07.

Now plug these values into the formula:

[ \text{g