Hot:13112014-02-17 11:00:55 From: FTD AUTOMATION INSTRUMENTS
FTLU Vortex Flowmeter selection precautions
Vortex Flowmeter Measuring Range
Vortex flow transducer can not be used to measure fluid with low Reynolds’ Number (Re≤2×10). Since Strouhal Number changes with low Reynolds Number, Meter accuracy will become less, and high viscosity fluid will affect or even prevent eddies generated. Therefore, should select product according to flowrate range in this catalog. For stable operation, flowrate would be better at 30 ~ 70% of vortex flow transducer measuring span. 4
Application below Reynolds’ Number should be limited.
High Temperature Type
When fluid temperature ≥250℃，must use high temperature type of vortex flow transducer.
Max. Temperature for Inserted Type vortex flowmeter
Inserted transducer is just used at location with fluid temperature≤120℃.
Temperature & Pressure Compensation of Vortex Flowmeter
Normally, it does not need compensation when measure liquid volumetric flow. When measure mass flow of overheated steam and volumetric flow of gas, it needs temperature & pressure compensation, and pressure (or temperature) compensation for mass flow of saturated steam.
Dirty of Fluid
Vortex flow transducer is applicable to a wide range of fluid, however, should pay special attention to dirty of fluid. Because fluid with solid particles eroding bluff body will cause noise and wear off bluff body. Short fiber intertwining bluff body will change meter factor.
Vortex flow transducer can be used to measure gas-liquid two phase fluid mixed with little dispersive even bubbles and volumetric gas content ≤2%; also can be used to sporadic, even solid particles, but volumetric solid content should be less than 2%.
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