Home » All Calculators » Engineering Tools » Fire Hose Friction Loss Calculator

Fire Hose Friction Loss Calculator

Photo of author
Published on

When it comes to firefighting, every second counts. The Fire Hose Friction Loss Calculator is an essential tool designed to help firefighters quickly calculate the loss of pressure due to the friction within fire hoses. This information is crucial for effectively combating fires, as it influences the decision-making process regarding which hoses and tactics to employ.

Understanding the Calculator's Purpose and Functionality

The primary purpose of the Fire Hose Friction Loss Calculator is to ensure that firefighters can predict and manage the water pressure needed at the nozzle to effectively fight a fire. The friction loss calculation is based on the Hazen-Williams equation, simplified for practical firefighting use. This simplification considers variables like hose diameter, flow rate, and hose length, which are critical for accurate calculations.

The friction loss (FL) formula is given as:

FL = C * (Q^2) * L

  • FL: Friction loss in pounds per square inch (psi)
  • C: Coefficient related to the hose diameter and type
  • Q: Flow rate through the hose in hundreds of gallons per minute (gpm)
  • L: Length of the hose in hundreds of feet

This formula allows firefighters to quickly determine the pressure loss, ensuring that the water reaches the fire with enough force to be effective.

Step-by-Step Examples

Example 1: Calculating the friction loss in a 1.5" diameter hose, 100 feet in length, with a flow rate of 200 gpm.

  1. Convert the flow rate to hundreds of gpm: 200 gpm becomes 2.
  2. Convert the hose length to hundreds of feet: 100 feet becomes 1.
  3. Use a common coefficient for a 1.5" hose, which is approximately 24.
  4. Apply the formula: FL = 24 * (2^2) * 1 = 96 psi.

The friction loss in this scenario is 96 psi.

Example 2: Calculating for a 2.5" hose, 50 feet long, with a flow rate of 300 gpm.

  1. Flow rate in hundreds of gpm: 300 gpm is 3.
  2. Hose length in hundreds of feet: 50 feet is 0.5.
  3. Common coefficient for a 2.5" hose is around 2.
  4. Apply the formula: FL = 2 * (3^2) * 0.5 = 9 psi.

The friction loss here is 9 psi.

Relevant Information Table

Hose Diameter (in)Coefficient (C)Example Flow Rate (gpm)Example Hose Length (ft)Friction Loss (psi)


The Fire Hose Friction Loss Calculator is an invaluable tool for the firefighting community. It simplifies complex calculations, allowing for rapid decision-making in critical situations. Understanding the friction loss in fire hoses ensures that firefighters can effectively manage water pressure, an essential factor in firefighting tactics. By optimizing hose selection and deployment strategies, firefighters can save time, conserve water, and, most importantly, save lives and property. The calculator's ease of use and the immediate provision of crucial data make it a staple in the firefighter's toolkit, proving its worth across numerous scenarios.

Leave a Comment