What is the total pressure loss for 600 feet of 3-inch hose flowing 400 gpm using the Condensed Q Formula?

To determine the total pressure loss for 600 feet of 3-inch hose flowing 400 gallons per minute (gpm) using the Condensed Q Formula, it's important to understand the application of the formula itself, which is used to estimate friction loss in fire hoses.

The Condensed Q Formula is expressed as:

[ FL = C \times (Q^2) \times (L) ]

Where:

• FL is the friction loss in psi.

• C is a coefficient that depends on the diameter of the hose. For 3-inch hose, this value is typically around 0.2.

• Q is the flow rate in hundreds of gallons per minute (gpm). In this case, 400 gpm is 4 (since we use hundreds).

• L is the length of the hose in hundreds of feet. For 600 feet, this translates to 6.

Substituting the values into the formula, we calculate the friction loss:

[ FL = 0.2 \times (4^2) \times 6 ]

Calculating further:

1. ( 4^2 = 16 )

2. Multiply by the coefficient: ( 0.2 \times 16 = 3.