If 300 gpm is flowing from a nozzle, what is the total pressure loss due to friction for 400 feet of 2 1/2 inch hose?

If 300 gpm is flowing from a nozzle, what is the total pressure loss due to friction for 400 feet of 2 1/2 inch hose?

• A. 50 psi
• B. 72 psi
• C. 100 psi
• D. 120 psi

Answer: (B)

To determine the total pressure loss due to friction for 400 feet of 2 1/2 inch hose when 300 gpm is flowing from a nozzle, it is essential to refer to established friction loss formulas or tables specific to fire service hydraulics. For 2 1/2 inch diameter hose, the friction loss can typically be calculated using the formula: **Friction Loss (FL) = (Q^2 × L) / C** where: - FL is the friction loss in psi, - Q is the flow in hundred gallons per minute, - L is the length of hose in feet, - C is a constant derived from hose diameter. At 300 gpm (which can be expressed as 3 when using the formula since Q is in hundreds of gpm), and referring to common friction loss coefficients for 2 1/2 inch hose, it is common to find a loss of approximately 2 psi per 100 feet of hose for this flow rate. Thus, for 400 feet, the calculation would be: **Friction Loss = (3^2) × (400/100) = 9 × 4 = 36 psi** However, due to the specifics of certain calculator tables

To determine the total pressure loss due to friction for 400 feet of 2 1/2 inch hose when 300 gpm is flowing from a nozzle, it is essential to refer to established friction loss formulas or tables specific to fire service hydraulics.

For 2 1/2 inch diameter hose, the friction loss can typically be calculated using the formula:

Friction Loss (FL) = (Q^2 × L) / C

where:

• FL is the friction loss in psi,

• Q is the flow in hundred gallons per minute,

• L is the length of hose in feet,

• C is a constant derived from hose diameter.

At 300 gpm (which can be expressed as 3 when using the formula since Q is in hundreds of gpm), and referring to common friction loss coefficients for 2 1/2 inch hose, it is common to find a loss of approximately 2 psi per 100 feet of hose for this flow rate.

Thus, for 400 feet, the calculation would be:

Friction Loss = (3^2) × (400/100) = 9 × 4 = 36 psi

However, due to the specifics of certain calculator tables