【Help】Discussion on the errors of flow meters at both ends of a 10-kilometer long pipeline
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Our plant has a 10 km long pipeline for transporting liquid materials. At normal temperature and pressure, the boiling point of this material is 72°. The diameter of the pipeline is DN50; the pressure at the inlet of the pipeline is approximately 7 kg, while the pressure at the outlet is about 2 kg. The flow rate ranges from 3 to 9 t/h. Emerson mass flow meters with a precision of 0.1% of the same model are installed at both the inlet and the outlet. It has been observed that there is a significant error between the two flow meters, amounting to 1%. This is the overall error over a period of one month. We would appreciate it if you could advise us on possible causes for this error. Thank you
Those familiar with metering know that for a single pipeline, two flow meters should not be installed – even if they are identical, this is not acceptable. Otherwise, endless disputes will arise, as two flow meters can never be exactly the same. Regarding the specific issue, I wonder if the parameters entered for the two flowmeters are exactly the same? Each one should enter the parameters for their respective location.
1 Perform zero-point calibration on the two flowmeters. 2 Determine which one is more accurate using other methods (such as liquid level), and adjust the coefficient of the other meter accordingly. We installed two Emerson mass flow meters side by side on the same pipeline, and there was a slight deviation; we followed the manufacturer’s advice when doing this.
Of course, a reasonable range of error is allowed
Thank you for the suggestion. At present, it has been found that the error resulting from level measurement is greater than the error between the two flowmeters
This post was last edited by 1111111 on 2018-8-1 at 20:27. 1. 0.1% accuracy? That’s just something to amuse kids – the actual accuracy of the flow meter is 1%. Anyone who disagrees, I’ll bite them with my pig’s mouth and chew them up to use as dog food :lol 2. How can they get the liquid level calculation wrong too? ! —— Damn it, idiot! That dumb bastard is dead. :Lol 3: People are so stupid; they just use the device blindly, without caring about accuracy or any other factors. If they’re rich enough and don’t mind spending money, that’s fine.
4. For vibrating tube mass flow meters, it is necessary to zero them regularly and frequently in order to achieve the desired accuracy
This suggestion can be considered, thank you
1. Check whether the media in both flowmeters is at full level in the pipe Are the parameter settings correct? ； 2. Regular zero calibration ； 3. Regularly compare the two flowmeters by placing them in close proximity at the same end; it is even better to send them for calibration on a regular basis if possible. Following the above points can reduce errors.
You must ensure that the liquid level measurement is accurate, and that the volume of the container is not affected by other factors; only then can the resulting flow rate be used as a basis for comparison.
It’s not a rule in metrology that ‘one pipeline should not have two flow meters’; rather, the supplier and the buyer agree on which meter will be used for settlement purposes (usually the meter on the upstream side), and which one will be used for monitoring and comparison. Additionally, it’s necessary to determine an acceptable range of error between the two flow meters. Under such premises, there generally won’t be endless disputes.