What is the estimated friction loss in 400 feet of 2-1/2" hose flowing at 300 gpm?

To determine the estimated friction loss in a specific length and diameter of hose flowing at a given rate, we can use the formula derived from practical firefighting guidelines. For a 2-1/2 inch hose, a common rule of thumb for calculating friction loss is:

Friction Loss = (Length in hundreds of feet) × (Flow rate in hundreds of gallons per minute)².

In this case, we have 400 feet of hose and a flow rate of 300 gpm. To apply the formula effectively, we first convert the parameters to fit the equation. The length of the hose (400 feet) becomes 4 (since 400 feet / 100 = 4), and the flow rate (300 gpm) becomes 3 (since 300 gpm / 100 = 3).

Now we can substitute these values into the equation:

Friction Loss = 4 × (3)²

Friction Loss = 4 × 9

Friction Loss = 36 psi.

This basic calculation results in a friction loss of 36 psi, but since we're considering round values and practical applications in firefighting scenarios, we need to factor in additional variables, which typically leads to an approximate adjustment.

Clearly,