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Volume of water flow

  1. Jan 5, 2009 #1
    A pipe broke on the roof of a public building here in Chicago. Although I am an electrical engineer and very rusty on hydraulics and water flow, I have been asked to estimate the amount of water dumped on the roof of this building, as follows:

    Diameter of the burst pipe: 3/4 in.
    Water temperature: 130 degr F
    Pressure: 15 lbs

    Water flowed for 45 minutes before being shut off. I assume the break allowed water to flow freely from a 3/4 in diameter opening.

    I would appreciate it if someone can send me the formula for this calculation. I have searched a number of PF postings, without luck.


  2. jcsd
  3. Jan 6, 2009 #2


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    Welcome to PF!

    Hi berniebs! Welcome to PF! :smile:

    Bernoulli's equation along a streamline (essentially, KE = work done ), assuming zero speed at zero pressure:
    pressure + (density)(speed)2/2 = 0

    and of course flow rate = speed x area.

    (For details to impress your colleagues with, see the PF Library :wink:)
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