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Micro Motion Coriolis Installation Orientation for dirty wet crude oil

Dear Micro Motion Coriolis Experts,

We have Coriolis ELITE series model CMFHC2M installed at our site, the flowing product is Dirty Wet Crude Oil (confirmed contained sand & particles).

Due to the limited space, we have to installed this unit at horizontal pipe. So, there's no self draining for this installation.

The question is which one is better between these option below related to accuracy and easy maintenance purpose.

1. Install coriolis with tube on below.

Potential weakness  : accumulated sand & debris on tube.

2. Install coriolis with tube on top.

Potential weakness  : gas trap on tube.

Please advise and recommendations, which one is preferred for our installation orientation related to accuracy and easy maintenance purpose.

Note : 

- Due to limited space, it has to be on horizontal pipe

- Service : Dirty wet crude oil

Thank you in advance,


  • Hello Faiz, there are a couple things that may affect our recommendation, but our standard recommendation for liquid flow in a horizontal line is for the tubes to be "down". A couple of comments:

    1) If the fluid has some viscosity (i.e. heavy or cool), it will hold the BS&W in suspension with very little settling or build-up expected.

    2) If the velocity can be maintained above about 1 m/sec, it has a self-cleaning effect whereby the moving fluid carrying particles will naturally scrape away any sediment that may have collected or adhered to the pipe surfaces.

    3) If sediment does settle out into the sensor tubes, the density measurement will be reflective of the combined sediment plus liquid (i.e. it will appear heavier than just the liquid portion), and the zero will be affected due to the imbalance of material between the two tubes, but the mass flow rate should still be an accurate reflection of the mass that is moving through the meter.

    4) Alternatively, allowing any bubbles to collect in a tubes-up orientation (i.e. light oil, low viscosity, hot) will cause significant measurement errors in the density AND the measured flow rates due to the decoupling effect of two-phase conditions.

    If you would like a more thorough review of your specific conditions, please send an email to with your fluid properties, flow rates, pressure, temperature, and installation details (separator type (2 or 3 phase), level control (snap or modulating), sketch of piping up and downstream of metering point with all equipment identified). Thanks for escalating your concern.