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Pressure Conundrum Please Help !

  1. Mar 27, 2014 #1
    Hi all !

    I currently in the process of retrofitting an old process line in which I require the outlet pressure to be 1.5 bar.

    The design just includes an open tank connected to a pump as shown in attachment. The water level of the tank is leveled with the pump outlet. The pump is currently operating to produce an outlet flow of 33 LMH in a 1.5 in pipe.

    By using Bernoulli's Equation, shown in attachment as well, I can't seem to increase the pressure by either manipulating outlet flow or reducing pipe size. I sincerely hope you guys can help by pointing out my mistake and a solution to increase the outlet pressure ?

    Thank you very much for your kind assistance ! .. :confused:

    Attached Files:

  2. jcsd
  3. Mar 28, 2014 #2


    User Avatar

    Welcome to PF Faizal.

    Is the pump capable of 1.5 bar? (see the specs)
    What do you expect to see if you would get 1.5 bar? Could it be that you get 1.5 bar and without a stop the pressure just does nothing?
    The speed of the flow is slow and there is a pump there so the two sides are not truly communicating. I see no need for the Bernoulli equation.

    Options for increasing the exit pressure:
    Overwork the pump/change the pump with something better. An overall clean-up will sometimes "up" the pressure.
    Move the water tank to a higher elevation, approximately 10m => 1bar.
    Make the exit pipes bigger for less friction.

    IMO the main culprit is the pump if you do not get 1.5 bar.

    Have fun!
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