How to choose a suitable Coriolis mass flow meter?
Coriolis Mass flow meters are not cheap, and it is very important to choose a suitable flow meter for your applications. When choosing a suitable flowmeter, you should communicate with the Coriolis mass flowmeter manufacturer and provide field application parameters. The following methods are for your reference:
1. Provide process operating conditions to Coriolis flowmeter factory
Process operating conditions are the basis for selection and calculation, and it should include the following:
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(1) What kind of fluid you measure, is it corrosive?
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(2) Fluid state: liquid, gas, vapor, steam, slurry, mud or other forms;
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(3)Fluid Flow rate: maximum, normal, minimum;
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(4) Operation Pressure maximum, normal, minimum;
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(5) Operation Temperature: maximum, normal, minimum;
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(6) Density range;
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(7) Viscosity range ;
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(8) Process pipe diameter; is it 15mm,1 inch, 2 inch or 3 inch dial size,DN100,6" or 8 inch mass flow meter ?
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(9) Allow measurement error;
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(10) Allowable pressure loss;
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(11) Allow the maximum flow velocity.
2. Select the Coriolis flowmeter size, sensor material and temperature range
The nominal diameter (inner diameter) of the Coriolis flowmeter should be equal to or smaller than the process pipe diameter. When selecting the sensor size, you should firstly consider flow range to choose coriolis flow meter sensor dial size according to the technical data sheet of the Coriolis flow meter factory, then select the flow sensor wet parts material according to your fluids type, also choose temperature , pressure rating according to the data sheets.
3. Calculate the pressure loss of the mass flow sensor
Calculating the pressure loss of the Coriolis mass flow sensor based on the diameter of the flow sensor is important.
When the fluid flows through the sensor, due to the friction between the fluid and the pipe wall and the internal particles of the fluid, in order to overcome the frictional resistance along the pipe, a certain pressure loss will be caused. Also due to the existence of bends, necking, flaring, diverters or confluences, etc., the magnitude or direction of the flow velocity is forced to change drastically in these local areas; a certain pressure loss must be caused. Coriolis flow meter structure also cause pressure loss when fluids passing through the mass flow sensor;
However you can ask Coriolis flow meter manufacture to calculate the pressure loss after you provide fluids, viscosity, flow range, operation pressure and temperature, pipeline size to them.
After calculating the actual pressure loss, it should also consider back pressure value.
4. Calculate the fluids velocity inside flow measurement tube of Coriolis meter
In order to reduce the fluids wear to the measuring tube, and more importantly, to prevent certain flammable and explosive fluids from being dangerous due to high velocity and generating high-voltage static electricity, the upper limit flow rate is usually specified The fluids max velocity should be within the design range of Coriolis flow meter
5. Coriolis flow meter accuracy
After selecting the Coriolis sensor dial size, you should also consider zero point stability and calculate its mass flow measurement accuracy. Zero drift has little effect on large flow rate mass flow meter, but when measuring micro mass flow fluids, you should consider zero drift;
Coriolis flow meter accuracy varies according to many factors, such as fluids viscosity, flow range.,etc; Even though it is the highest accuracy flow meters which can achieve accuracy 0.1.0.2%, but for viscous liquid mass flow measurement or micro mass flow measurement, the accuracy will be poor.
6. Coriolis flow transmitter Selection
After select the Coriolis flow meter size and material, we now need to consider digital flow transmitters:
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(1) Flow sensor structure: remote display with cables or integral display?
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(2) Power supply : 24V DC or 220V AC; for remote display mass flow transmitters, the cables between sensor and transmitters could not be so long, because the mass flow signals become week after long distance transmission;
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(3) Signal output
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Some transmitters can provide multiple signal output methods at the same time, and you need to make a selection when selecting a model. For example, whether the analog s 4-20mA or 0-20mA output, or 0-5V, and pulse output or frequency output;
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(4) Choice of communication and interface
For example, do you need RS485, MODBUS, HART, or PROFIBUS protocol, etc.;
Only in above method, you can choose the correct Coriolis mass flow meters, welcome to contact www.silverinstruments.com to provide your applications parameters to us and obtain the
lowest price cost for Coriolis flow meter.
