Fire Protection Research Foundation report: "Determination of Fire Hose Friction Loss Characteristics"
Author: Joseph L. Scheffey, Eric W. Forssell and Matthew E. Benfer
Date of issue: April 2012
(revised October 2013)
The calculation of friction loss in fire hose is a common task for fire fighters responsible for operating fire apparatus pumps. This is required to deliver water at the proper flow rate and pressure to fire fighters controlling the fire hose nozzle. Pressures and flow rates too low will be insufficient for fire control, while pressures and flow rates too high create dangerous conditions with handling the nozzle, burst hose and other hazards.
Baseline friction loss coefficients used by today’s fire fighters for calculating fire hose pressure loss were derived using hose design technology from upwards of 50 years ago. A need exists to update these coefficients for use with today’s fire hose. Modern fire hose is generally perceived by fire fighting professionals as having less friction loss and different performance characteristics than the hose on which these coefficients were originally based. The focus of this study has been to develop baseline friction loss coefficients for the types of fire hose commonly used by today’s fire service, and identify any additional performance characteristics that should be considered for friction loss calculations.
Notice of Revision (October 2013: This report was issued in April 2012 and revised in October 2013. Changes other than editorial are indicated by a vertical rule beside the paragraph, table or figure in which the change occurred. These rules are included as an aid to the user in identifying changes from the previous edition. Changes have been made due to an error in the calculation of the dimensionless friction factor, ƒ. The calculations of the C factor and the CD factor were not affected by the error. The revision effected Tables 6, 8, 9, and 10, Figure 9 in the main body of the report and Figures C.1 through C.7 in Appendix C. Equation 5a on page 6 was revised and a note was added below this equation.