The impact of insufficient length in the straight sections before and after a steam vortex flow meter on measurement errors
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Recently, the company installed steam vortex flow meters, but the straight pipe sections before and after the installation location do not meet the required specifications. The steam pipeline has a diameter of DN150, and according to the requirements in Chart 16R405, the straight pipe section ahead of the flow meter should be 2250 mm long, while the straight pipe section behind it should be 1050 mm long. In reality, the length of both straight pipe sections is less than 400 mm, and there are multiple bends and valves within 1 meter of each end. Such conditions will certainly result in large measurement errors; I would like to know whether these errors are negative or positive. Thank you all, guys
It’s difficult to clarify this situation, but from a theoretical perspective, the flow meter reading should increase because there isn’t enough straight pipe section; especially ahead of the flow meter, the flow of fluid in the pipeline becomes chaotic, resulting in pipeline vibration. Since vortex flow meters measure flow based on frequency, the flow rate will increase.
There is an error, but it’s not that large! The key is to see what the steam flow is like.