Calculating the Pressure Drop and Power in Pipe Flow: Summary

The answers to the ConcepTests are given below and will open in a separate window. 
Key points from this module:
  • The mechanical energy equations include head loss which accounts for friction in the flow.
  • Major head losses consist of straight pipe while the minor losses take into account changes in the pipe, including bends and turns as well as valves, pumps, etc.
  • Friction factors can be determined from the Moody chart.
  • Pressure drop can be calculated using the energy equation.
  • Power can be calculated by determining the pump head.
From studying this module, you should now be able to:
  • Calculate the pressure drop of a pipe given its diameter and length as well as the fluid flow rate.  
  • Use the Moody chart to calculate friction factors.
  • Calculate major and minor head loss for both laminar and turbulent flow. 
  • Calculate power based on the pump head term in the energy equation.


Prepared by Janet deGrazia, Department of Chemical and Biological Engineering, University of Colorado Boulder