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Coriolis ELITE series installed near transmission pump.

Dear Micro Motion Coriolis Experts,

I have 2 (two) questions related to Coriolis Elite Series

1. We have Coriolis ELITE series model CMFHC2M installed at our site near transmission pump. Will this affect the coriolis accuracy due to pump vibration?,

 If Yes, what is the best installation consideration for Coriolis meter after transmission pump.

2. We are planned to installed new Coriolis Elite series at our site and the flowing product is Dirty Wet Crude Oil (contained sand & particles). We choose to install with vertical orientation (Bottom Up) as below isometric diagram, is it appropriate?

   

Thank you in advance,

Faiz

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  • It can be affected by pump vibration. Decoupling the meter and pump from one another to minimize the effects of vibration is recommended.

    Consider mounting the pump and meter in separate skids if possible.

    Using vibration damper pipe couplings to reduce vibration on pump discharge piping.

    Focus on minimizing pump to meter vibration transfer in your pump mounting design and pump selection if possible.
  • It can be affected by pump vibration. Decoupling the meter and pump from one another to minimize the effects of vibration is recommended.

    Consider mounting the pump and meter in separate skids if possible.

    Using vibration damper pipe couplings to reduce vibration on pump discharge piping.

    Focus on minimizing pump to meter vibration transfer in your pump mounting design and pump selection if possible.
  • The orientation of the meter in the diagram you have shown is ideal.
  • In reply to Tom Hayes:

    What is the minimum vibration tolerance?
  • In reply to georjoe:

    I suspect pump sensitivity a bigger problem at frequencies or harmonics of frequencies that are close to the tube frequency. The tube vibrational frequency is determined through changes in tube material stiffness and how and where the tube (or tubes) are mounted.

    Pipe supports at locations that would reduce transmission of pulsation might also help in addition to flex couplings on the pump discharge.

    Some meters appear to be sensitive to turbulent flow. Pipe vibrations from pumps might induce a similar flow disturbance problems.

    The manual will state the maximum vibrational tolerance. This tolerance is related to electrical code compliance and is a test of how reliable and precise the device electronics are under a vibration test.

    A simple test would be determining if pump vibration impacts prover meter factor.

    Prove the meter with no discharge flex coupling and record meter factor.

    Prove the meter with flex coupling if the meter factor changes, We have a problem Houston!

    I would prove at multiple flow rates and produce a md curve so you can determine if pump speed is a sensitivity.
  • In reply to Tom Hayes:

    It is correct that the interference due to mechanical vibration should normally only occur when the frequency of the pump and the vibrating frequency of the measuring tubes match to within 0.5 Hz of each other. This is quite a rare coincidence. The vibrating frequency of the flow meter tubes changes over a limited range of frequencies as the fluid density changes (this is actually how the Coriolis meter measures the density of the fluid). So if the meter and the pump area already operating at frequencies very close to each other and either the pump is varying speed up and down and/or the fluid density is changing regularly, you might see one of those cases where these two frequencies cross each other periodically. Even when this occurs, it does not always necessarily cause too much trouble for the measurement because the Micro Motion meters are now so well balanced that the measuring tubes are well isolated from external vibration sources, even when they match. As Tom pointed out, firm mounting of the meter and flex couplings can further isolate the vibrations from each other, if needed.

    Our literature does state vibration limits for the meters and electronics For example, the 5700 is rated to meet IEC 60068-2-6, endurance sweep, 5 to 2000 Hz up to 1.0 g. However, our published vibration and shock ratings are meant to protect against damage to the components and are usually of most interest if you plan on mounting the metering equipment on a truck. Other than the rare <0.5 Hz match with the measuring tube frequency, there is no other need to worry about vibration effecting the measurement accuracy.
  • In reply to Marc Buttler:

    What frequency do the Micro motion tubes typically vibrate at?
  • In reply to Tom Hayes:

    Each model and size will operate over a different range of frequencies.
    Smaller meters and meters with straight or slightly bent tubes will operate at higher frequencies than larger meters and meters that are designed for peak measurement sensitivity and accuracy.
    The larger CMFHC2 in this question typically operates in the range from 75 to 95 Hz, depending on the fluid and whether it is liquid or gas. The highest frequency meters are the straight tube meters that run close to 650Hz. These are less sensitive for flow and density measurement, but are well suited to specialty applications.
  • In reply to Tom Hayes:

    Thanks for the advise on how to ensure the Coriolis accuracy not affected by pump vibration.
  • In reply to Marc Buttler:

    Thanks for the clear explanation and technical clarification.
    Now, we don't need to worry about vibration effecting the measurement accuracy.