Using the hand method, what is the estimated friction loss for 300 feet of 2 1/2-inch hose at a flow rate of 200 gpm?

• A. 12 psi
• B. 18 psi
• C. 24 psi
• D. 30 psi

Answer: (C)

The estimated friction loss for 300 feet of 2 1/2-inch hose at a flow rate of 200 gpm can be determined using the hand method, which is a simplified approach for calculating friction loss in fire hose. According to the standard tables and calculations, for a 2 1/2-inch hose, the friction loss can be approximated based on the length of the hose and the flow rate.

For every 100 feet of 2 1/2-inch hose, there is a friction loss of roughly 2 psi per 100 gpm of flow. Since the flow rate is 200 gpm, the friction loss would be doubled. Thus, for 300 feet, the calculation would proceed as follows:

1. Calculate the friction loss per 100 feet:

• The loss is approximately 4 psi for 200 gpm (2 psi for each 100 gpm of flow).

2. Then, for 300 feet:

• The friction loss for 300 feet can be calculated as:

• 4 psi (for the first 200 feet) + 2 psi (for the additional 100 feet) = 6 psi

When we combine this with the length of the hose