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I need to select a suitable diameter for my pipes

  1. Mar 12, 2010 #1
    Hi guys,

    Please help me out, I have a project here I need to design a pipe network system using Hardy Cross method.

    I have drawn my pipe network and done my distribution of the flow rate according to the give discharge. but now I'm not sure which method I should use in selecting pipe sizes.

    Pleasr help me out.

  2. jcsd
  3. Mar 12, 2010 #2
    What is it that you are trying to optimize? Cost, volume, efficiency, weight? The only fluids related parameters pipe size effects is the pressure loss (head) in the piping system and the fluid velocity. All these relationships can be found using Moody's diagram and models such as the Hagen-Poiseuille equation.

  4. Mar 12, 2010 #3
    Surely any reasonable size will do?

    The Hardy Cross method is really an iterative method for solving a system of linear simultaneous equations.
  5. Mar 24, 2010 #4

    I was also thinking of considering Hardy Cross. But I'm only given a flow rate of 15000 cubic meters and I believe I have to make assumptions for the selection of diameters but again how far in assumptions should I get with the above flow rate?

    Also can you guys tell me: what are the properties of helium gas at 900 degrees celcuis. I believe this is an inert gas that can be solidified at high pressures
  6. Mar 24, 2010 #5

    I'm looking on both volume and cost only
  7. Mar 25, 2010 #6
    IIRC, that's incorrect. I don't even think there's a industrial use for liquid helium.

    Helium does not solidify or liquefy outside of extreme lab environs. At least on earth.
  8. Mar 25, 2010 #7
    You want to size the pipe so that your velocities are fairly low. If its something generic, size it to about 7 ft/s. Dealing with gas is a little more complicated as its compressible, really depends on how much volume you want at your outlet
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