What could be the reason why the differential pressure value of a bent-tube flowmeter is much higher than that indicated in the calculation sheet?
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For measuring water-gas, the calculation sheet is very detailed, and the conditions under standard conditions are correct as well. The differential pressure value indicated in the calculation sheet is 200 Pa, but the actual value is 1300 Pa. What could be the reason for this?
The original poster used the unit ‘pascal’. Pascal is a very small unit; purely in terms of numerical values, there is indeed a large difference. However, in practical applications, this difference isn’t that significant. Moreover, there is always a gap between theory and practice, and I personally think it’s better to rely on practical considerations
A bent-tube flow meter is not a standard throttling device; there are differences between calculations and actual values, so flow calibration is required.
Personal opinion; please correct me if I’m wrong. First, verify that the pressure sensing pipeline is unobstructed. Shut down the secondary valve assembly and drain it. Use a custom-made connector along with a standard pressure source to calibrate the transmitter. If the transmitter is functioning properly, the measured values can be trusted. Secondly, it’s difficult to obtain accurate differential pressure readings at low flow rates; it’s possible that the transmitter’s amplification circuit is too sensitive. In cases where the device is used for measuring total volume, this error becomes significant. However, for detection and control purposes, it works fine in practice. A low-cost solution is to consider a reading of 1300 Pa as normal
What is the diameter? It would be best to provide the calculation sheet to check for any errors, and also to see if water is entering due to positive pressure