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Recent content by sboswell

  1. sboswell

    Centrifugal pump curve falls short of factory test

    forgot the attachment. in summary to my last post, which is basically answering all of the last few questions, I've gotten the pump to run on the curve by eliminating drag inducing elements between the pumps discharge and the original discharge gauge location. The elements are still there I've...
  2. sboswell

    Centrifugal pump curve falls short of factory test

    Ten Penny, yes the CCW rotation I called out is from the suction side looking at the face of the impeller. thanks for setting me straight, i was not sure which side is the proper side to call the rotation from. It is rotating CW from the coupling side looking at the pump. We ran it backwards...
  3. sboswell

    Centrifugal pump curve falls short of factory test

    I think I have solved the issue. The discharge gauge was too far downstream of the pump and between the pump there was a 90 degree elbow, a rubber expansion joint and a bushing to 2" pipe. There were too many drag inducing components which came into play between the pump and the disch gauge...
  4. sboswell

    Centrifugal pump curve falls short of factory test

    bumped the pumps backwards in the CW direction. max flow with valves fully open was 26gpm, i could hear cavitation so I turned the pump off. I'm sure they are going in the correct direction. Based on a few things going on with the discharge piping its occured to me to simplify the piping...
  5. sboswell

    Centrifugal pump curve falls short of factory test

    CCW rotation is correct for the pump & i've verified this. I've attached pictures of the area. there is 2" piping downstream of the process diagram i uploaded; roughly 100 ft of it going up 6ft in elevation and dumping into a tank. I've also used this tank to confirm flow numbers using...
  6. sboswell

    Centrifugal pump curve falls short of factory test

    Oops. I meant to say that the pump runs quiet, and at times it is hard to tell if it is even on. by that I do not mean it changes much in loudness.
  7. sboswell

    Centrifugal pump curve falls short of factory test

    Ok, posting the original factory performance testing and my latest run of field tests as well as a process diagram. I have worked around pumps that had cavitation problems before so i can assure you this is not occurring. The pump runs extremely quiet at times its hard to tell if its even on...
  8. sboswell

    Centrifugal pump curve falls short of factory test

    thats a fair point Quality time, I would say that I am not very experienced in this field. cant speak for the people at the factory. I've corrected them using the following assumptions and removing suction pressure from the discharge pressure. the suction gauge is 1' higher than the cl of the...
  9. sboswell

    Centrifugal pump curve falls short of factory test

    Yes, these pumps have been only used for testing and are brand new. impeller clearances have also been tested at a few different settings but have stayed at the factory recommended and have not changed during the factory test or our field test. the casing and impeller material are hastelloy...
  10. sboswell

    Centrifugal pump curve falls short of factory test

    Quality time, first off thank you for your response. The calculations are done, using the catalog curves(factory testing efficiency data). they were pretty jumpy so i used a trendline and its equation to get a smooth number to use in my tests. I'll be honest here I can see that my numbers for...
  11. sboswell

    Centrifugal pump curve falls short of factory test

    Let me address the strange figures CH50H. suction pressure in the manufacturers test were denoted as being ABS or absolute pressure. I take that to mean it is an actual height of water on the suction side in a stand pipe + 1 atm or 33.9 ft. not sure why they did it that way. The figures for...
  12. sboswell

    Centrifugal pump curve falls short of factory test

    yeah it is a funky curve. what I've received from the factory is a smooth graphical pump curve that I can overlay with the hard data I also received from them. Their raw data is pretty bizarre when plotted against a smooth trendline. nonetheless what could cause the massive loss of flow in...
  13. sboswell

    Centrifugal pump curve falls short of factory test

    against the factory testing that is.. This is a drop of a substantial amount. close to 20 gpm difference at 30ft of discharge head which is the lowest our piping system will go. pump shutoff measured here and at the factory is 47 ft. NPSH is 2ft, 2.0hp, 1750rpm, pump is a 6.125"...

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