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  1. UtahWater

    How is this possible? Q re: "identical" booster pumps

    The butterfly valves were not able to open completely to varying extents between the two pumps. The rearranged valves on the discharge allowed them both to open fully and the pumps now operate nearly identically. Lessons learned: make sure that valves can operate completely, design the suction...
  2. UtahWater

    How is this possible? Q re: "identical" booster pumps

    We pulled the pump today. No obstructions, nothing apparently out of place. The suction piping is a bit different between the two pumps, but my most recent theory is that the butterfly valves on the discharge lines are mated directly to the silent check valves. The butterfly valves are...
  3. UtahWater

    How is this possible? Q re: "identical" booster pumps

    Thank you all for your input! We are pulling and inspecting the pump with low flow later this week. Will post whatever determination we come to.
  4. UtahWater

    How is this possible? Q re: "identical" booster pumps

    Thanks, ashtree. The pumps were ordered with a non-witnessed test. The "Performance test results" included serial number and tester name as well as tabular data along with the resulting curve. Each pump has its own unique test result...two differeent S/N.
  5. UtahWater

    How is this possible? Q re: "identical" booster pumps

    Thanks, SandCounter. These are Flowserve 12EQH (100 hp, AC drivers at 1770 RPM) with 9.25" impellers. Application is for potable water service. The branch on the north line is a pressure relief valve. No leak through. Thanks for the idea that maybe something happened to an impeller on...
  6. UtahWater

    How is this possible? Q re: "identical" booster pumps

    bimr, yes the gray pipe on the right is the suction piping. It is 14" diameter. The discharge piping on the left is 12" There is a mag meter (tube) in a vault on the suction side, out of view to the lower right. There is an isolation valve on each side of the meter, but no isolation valves on...
  7. UtahWater

    How is this possible? Q re: "identical" booster pumps

    Flow is from right to left in the plan sheet above. 14" suction pipe on the right side from a ground level tank (about 40' of pipe; NPSHa calculates to about 1.6xNPSHr at low water level), 14" tee and elbow, 20" diameter cans with 14" suction flanges, 8' vertically from suction flange to 12"...
  8. UtahWater

    How is this possible? Q re: "identical" booster pumps

    Thanks, Bimr Available test data below and layout attached: 5/2/2018 3Ph/480V North Pump sequence Q (GPM) P (ft) I (amps) 2 1357 162 112 3 2146 139 122 4 2178 139 122 1 2300 145 123 5/2/2018 3Ph/480V South Pump sequence Q (GPM) P (ft) I (amps) 4 1332 162 113 3 2345 139 ? 1 2345...
  9. UtahWater

    How is this possible? Q re: "identical" booster pumps

    Sorry - very incomplete original post. Two vertical turbine can pumps pulling water out of a ground level tank. Common suction line out of tank to manifold. Only one pump operates at a time - duty/standby Each pump during their respective tests during startup, on the same gauge (moved from one...
  10. UtahWater

    How is this possible? Q re: "identical" booster pumps

    Please help me understand flows in a newly installed pump station. Two booster pumps that came with NW factory tests have materially identical performance curves, yet in practice, they produce identical discharge head, but with 7% difference in flow. How theoretically or practically is that...
  11. UtahWater

    Adhesion test and topcoating

    What kindof adhesion numbers indicate a satisfactory candidate for top-coating? We have a steel tank with a 40 y.o. lead paint on the exterior that was topcoated 18 years ago with a Macropoxy 920 primer and Corothane II Urethane. The more recent topcoat is showing localized spots of...
  12. UtahWater

    Water Model Rules of Thumb?

    We don't shoot for a certain number. We go for what looks to be spatially representative and hydraulically unique situations seem to dominate, with only a few spread throughout the 'heart' of the network. I'd say for a rough guess that we request tests on only 2-5% of the system's hydrants...
  13. UtahWater

    Poisson pull out effect restraint

    Thanks, bimr. Yes, I've studied PP813-TN lately. I'm not suggesting that the Poisson effect doesn't apply to buried pipelines, I'm looking for a specific mention of how skin friction effects (affects? I'm never quite sure) the pullout results of the Poisson effect. In the case of a buried...
  14. UtahWater

    Poisson pull out effect restraint

    rconner, do you happen to have links to the presentation and/or white paper from that conference? I haven't yet had a call back from Performance Pipe engineering to get their take on this question that I haven't seen addressed in any documentation. I would be interested in seeing what research...
  15. UtahWater

    Poisson pull out effect restraint

    FYI - I just spoke to a 30-yr veteran engineer in HDPE and he says that he's never seen pullout due to Poisson effect in a buried application. Pullout due to not letting the pipe come to thermal equilibrium, or not letting it relax after a pull, yes, but no on Poisson's.
  16. UtahWater

    Poisson pull out effect restraint

    Thanks, bimr and rconner, for the input.
  17. UtahWater

    Poisson pull out effect restraint

    Thanks, bimr. In this particular case, I've calculated 20,000#+/- Poisson effect Force and the resulting thrust block (anchor to be poured around a molded wall anchor fitting) from our structural eng. is 10' tall, 5' wide and 2' thick with #5 reinforcement on each face. I'm OK with having this...
  18. UtahWater

    Poisson pull out effect restraint

    We are designing a 20" ID HDPE potable water pipeline. PPI's design bulletins have been useful, but seem to be somewhat incomplete in at least one area. When calculating the Poisson pullout effect force, nothing is mentioned of the restraint developed due to the soil-pipe friction along the...
  19. UtahWater

    How to prevent another leaning tower of pisa

    Thanks, civilperson. You're right about the design fee being too small...$6,500 doesn't pay for very many tilted manhole sections after overhead and wages.
  20. UtahWater

    How to prevent another leaning tower of pisa

    dgillette, thanks I appreciate the feedback. It supports my theory that you can't really design something to succeed if you don't know what you're building on, you can only give an educated guess. Plus, it made me smile...man, somebody was teaching me about personality traits yesterday...I am...

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