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I Needing to know the pressure in a water tank

  1. Nov 7, 2018 #1
    At work, we have a cylindrical tank that holds water. The tank is 5 feet round and about 6 feet long putting the highest part of the tank at about 6 feet off the ground. The tank holds 1000 gallons of water. There is a valve on the bottom that I am needing to test and I can’t seem to find a formula to give me the psi to test it on that would simulate it being filled with 1000 gallons of water. Any help is greatly appreciated
  2. jcsd
  3. Nov 7, 2018 #2


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    The max pressure at the bottom of the tank is equal to the pressure of the max depth of water above the valve.
  4. Nov 7, 2018 #3


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    The formula you need is:
    P = ρ h g
    I haven't put the numbers in but you can insert the values.
    The density (ρ)
    of water is about 62 pounds per cubic foot.
    and g is about 32 ft/s2
    That answer would be in pounds per square ft so you would need to divide by 122 for the pressure in pounds per square inch.
    The area of the tank is not a factor so you just need to use the 6 feet depth.
    Alternatively you can work on the fact that 1Atmosphere will support around 30 ft of water. Your 6ft tank will be about 1/5 of an Atmosphere and, in old money, 1Atmosphere is 14 lbs / inch2
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