How should the metal tube float flowmeter be calibrated when the inlet gas pressure is 10 MPa?
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Dear sea friends: A metal tube float flow meter is required for the pipeline system, with a diameter of DN25. The gas pressure at the inlet of the flow meter is 10 MPa, while the outlet leads directly to the atmosphere. Therefore, when ordering this metal tube float flow meter from the manufacturer, should the calibration pressure be set at 10 MPa or at atmospheric pressure of 101325 Pa? If calibrated at 10 MPa, it doesn’t seem quite right ； But if calibrated at normal pressure, it seems there is a pressure of 10 MPa at the inlet of the flow meter – what a dilemma! Thank you!
If the pressure that can be withstood is 10 Mpa, then it should be customized for 16 Mpa, right?
The factory calibration of rotameters is generally carried out using air as the medium under conditions close to those of actual operation. However, for factory calibration, it may not be carried out at a pressure of 10 MPa; instead, calibration can be done under a lower pressure, and then conversion can be performed using relevant factors related to pressure and the medium. The accuracy requirement for rotameters is not high; calibration is sufficient.
I’ve never seen a flow meter installed on a hydrogen vent pipe~~ It’s generally not used for continuous venting, so what’s the point of installing a flow meter?~~
The metal tube float flow meter mentioned by the poster probably won’t work: the gas pressure at the inlet of the flow meter is 10 MPa, while the outlet leads directly to the atmosphere; in other words, the pressure difference across the flow meter is 10 MPa, which results in a very high flow velocity that far exceeds the normal flow rate allowed by the flow meter.
This post was last edited by hlgcqx on 2017-6-13 at 15:47. It’s not feasible to install a metal rotameter for venting; as a reference, one can consider whether a flow meter can be installed on the main vent pipe of the combustible gas venting system - Powered by Discuz! http://bbs.hcbbs.com/thread-616696-1-1.html
The nitrogen is vented from the testing setup, and the customer needs to know the flow rate of nitrogen vented during a particular test. Is it appropriate to install a flow meter at the end of the pipeline? Is it accurate?
For the pressure rating after the vent valve, N can be chosen, which corresponds to 25 bar~~ But as mentioned above, it’s difficult to select an appropriate flow rate in your case; since venting involves variable flow rates, the flow meter should be selected based on the maximum instantaneous flow rate~~ Can you afford such an investment? The original poster might consider using other methods for measurement, such as yield or volume changes~~
I wonder where I saw the term “hydrogen”~~ Hehe~~:L
The pipeline is relatively thin and the flow rate is not high, at 20 Nm3/h; it’s just that the inlet pressure is high. In such a situation, it seems that using a flow meter calibrated at atmospheric pressure isn’t very appropriate – is the value displayed the actual flow rate?
It’s difficult to make a choice~~ It’s more practical to determine the vent volume indirectly~~