Calibration pressure for metal tube float flow meters
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This post was last edited by A Chao syc62100 on 2017-2-18 at 11:50. Condition description: Nitrogen pipeline, with a pressure of 5 MPa; a metal tube float flow meter of DN25 is installed at the outlet, and the outlet of the flow meter has a DN25 flange that leads to external venting. Question: Is it appropriate to calibrate this flow meter using standard conditions (20°C, 101325 Pa)? The technical staff from the flow meter manufacturer say that the inlet pressure of a flow meter equals the outlet pressure plus the flow meter’s own pressure loss. Therefore, there is no need to consider the 5 MPa pressure in the upstream pipeline; since the flow meter discharges directly to the outside, its inlet pressure is equal to atmospheric pressure (101325 Pa). Of course, the flow meter’s own pressure loss is very small and can be ignored for now. So, atmospheric pressure is used as the calibration pressure. Is this statement correct? I’m confused; the pipeline pressure on the front end is clearly 5 MPa, right? Thank you to all the masters and fellow sea travelers.
1. First, check whether this float-type flow meter is capable of measuring the flow rate, and whether its range is appropriate. If it is, use it as such; you can then see what the range of flow rate variations is. 2. I have a question: why is the metal tube float flow meter emptied directly? There is no outlet valve, which doesn’t comply with the installation specifications! 3. As the manufacturer, we will ask you about the pressure required when placing an order; I will then determine how to provide that pressure in order to meet your requirements. 4. If technical discussions take place before placing an order, I would recommend that the flow meter be equipped with valves at both the inlet and outlet. When in use, all the inlet valves should be opened, while the outlet valve is used to regulate the flow rate. The pressure will be calibrated at 5 MPa; this approach can also help address issues related to fluctuations in flow rate. In summary, what you said is incorrect; your flow meter cannot be emptied directly – a valve is required. Therefore, the pressure should be calibrated at 5 MPa.
Thank you, I’ll think about it further, {:1_90:}
5MPa, just vent it directly through the flow meter? Is there no noise at the site? Use a flow meter as a throttle valve?
Designed specifically for carrying out certain test experiments, hehe