Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Water friction in pipes, hot vs cold?

  1. Jul 7, 2006 #1
    I usually use an average number of 2 kPa friction loss for normal tap water in pipes. Does anyone know if this number changes significantly up or down for water which is around 80 degrees C instead of 5?
  2. jcsd
  3. Jul 7, 2006 #2


    User Avatar
    Science Advisor

    Well, you're looking at only a 3% change in density but a factor of 4 change in the viscosity. Looking at Reynolds numbers (with a constant velocity and ID), this results in a very similar friction factor. I get about .01 vs. .012 for a smooth pipe. I didn't really go any further with the numbers. It looks though like you're not going to see anything noticible. You might do a couple of quick calcs adjusting your density and viscosity to match the two temps.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook