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Homework Help: Affinity Law and Efficiency of a Pump Curve

  1. Feb 26, 2017 #1
    1. The problem statement, all variables and given/known data
    (Pump Curve given as attachment)

    Find the point where the pump is delivering 1,200 gpm at 45 ft of head.
    What is the pump efficiency (read from the pump curve data)?
    ii. What is the hp delivered to the water?
    iii. What is the shaft hp required to drive the pump?

    2. Relevant equations
    HP = CFM * Inches of Water Column/6356 * Efficiency

    3. The attempt at a solution
    I believe the efficiency is at 72.5% looking at the graph.
    ii. 1200 * 30/6356 * .72 = 36,000/457,632 7.866 hp (I used 30 inches of water from the graph is that correct?)
    iii. plot pump hp is 19hp, shaft hp=19/0.725=26.2 hp

    Attached Files:

    • pump.png
      File size:
      142.6 KB
    Last edited: Feb 26, 2017
  2. jcsd
  3. Mar 3, 2017 #2
    Thanks for the thread! This is an automated courtesy bump. Sorry you aren't generating responses at the moment. Do you have any further information, come to any new conclusions or is it possible to reword the post? The more details the better.
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