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Making my own fire hose

  1. Jan 22, 2010 #1
    I had an idea the other day and I wondered whether or not it was possible. I want to build a water tank hooked up to a hose that can fire with the force of a real fire hose ( I'd really be delighted if I only reached half that ). Here's what the numbers:

    A fire hose has roughly 8 bars of pressure.
    Roughly 10 meters deep of water creates 1 bar.

    It would be impractical to build my a cylindrical tank be roughly 80 meters high. Instead, I was thinking that I could use a conical shape tank. Would a conical tank of the same height and hole width at the bottom as a cylindrical tank have more pressure because of the extra water on it? Does it matter what size the hole is at the bottom?

    Let's say the hole was 2 centimeters wide, the cylindrical tank will need (pi*(r^2)*h) (3.14(2[centimeters]^2)*8000[centimeters]) = 100480[milliliters?]. Using (pi*(r^2)*h)/3 for the cone volume, to try to get the same volume, (3.14(2^2)*x)/3 = 100480, x = ?). My mathematical abilities all break down here. I've been trying this for a while but can't figure it out.

    Basically, will a smaller conical tank create the same pressure of a larger cylindrical tank and how high would I need the tank to be to reach the 8 bars or so pressure (I'm trying to get it all the way up to my roof).

    All responses are appreciated. Thanks :)
  2. jcsd
  3. Jan 22, 2010 #2


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    Staff: Mentor

    No, the pressure just depends on the head (height of water). You need a pump -- that's what firetrucks use anyway.
  4. Jan 22, 2010 #3
    Dang :( Thanks :D
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