Micromotion Coriolis Mass Flow Meters

[butelja]

Has anyone come across any allowable ambient vibration spectrum parameters for locations where Micromotion coriolis mass flowmeters will be installed? From experience, we know that "high" ambient vibration is a problem. However, our knowledge is only qualitative, not quantitative.

For those not familiar with these flow meters, they function by sending fluid through 2 U shaped tubes which act as cantilever beams. The tubes are vibrated in oposition to one another. Mass flow around the U bends leads to coriolis effects which cause a twisting of the tubes. This twisting is detected as a phase shift between the 2 U tube legs. I believe the meters operate at a frequency around 80 Hz.

 

[ArtR]

MicroMotion does not publish quantitative data on allowable vibration.
However, the sensor instruction manual, section 3, mounting, does give pipe support guidlines, and the names of 2 companies that make vibration isolators.

Most chemical plants do not have high ambient vibration, unless you attach the meter directly to a reciprocating pump. Putting a flex section upstream of the meter, and mounting the meter to a building column usually works.

 

[dcasto]

Flow induced vibration is a problem for liquids near their vapor pressure We used them on ethylene near 1000 psig and 70 degrees F and had problems with noise that shutdown the electronics as the rates increased and the ethylene flashed in the tubes. We never saw any other problems from typical piston pump feeding them on other products like ethane/propane mixes.