The steam flow meter is inaccurate
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Orifice flow meter, but the pressure downstream is higher than that upstream. Never seen it before. Who has similar experience? Thank you!
The poster asked to be more detailed or clear: is the pressure higher downstream than upstream? Are it the pressure gauges before and after the flow meter that show it?
It can be checked from the following two aspects: 1. Check whether the orifice plate is installed incorrectly – the flared end should face downstream; please verify this. 2. Is there a short circuit between the downstream pipeline and a certain high-pressure pipeline?
This situation may be due to different amounts of condensate water in the measurement pipelines, with the liquid level in the negative-pressure chamber being higher than that in the positive-pressure chamber； It could also be due to steam supersaturation; since the measurement is taken of the vapor-liquid phase, this situation can occur. Providing information on the installation location of your throttle device will help everyone make a judgment.
Check the user’s situation to see if there is a source at the downstream end that has been connected to the pipeline network； Check the installation status, mainly to see if the condensation tank is at the same level ；
Check whether the positive and negative pressure tubes are connected reversely.
“It could also be due to steam supersaturation; since the measurement is taken of the vapor-liquid phase, this situation can occur. ”It’s very likely to be this reason. It is under renovation, with the negative pressure chamber and positive pressure chamber being lowered in position.
It is determined from the reading of the differential pressure transmitter.
1. If it’s a new installation, it could be a problem with the instrument or the installation location not meeting the requirements. 2. If it wasn’t there before but appeared after use for some time, then blockages in the condenser tank and pressure transfer lines should be considered; of course, instrument-related problems also need to be ruled out.
This is a common problem with newly installed instruments; there is a blockage in the positive pressure chamber.
This situation could be due to: 1. Air present in the positive pressure measurement line; 2. Heat tracing causing a large temperature difference between the two pressure measurement lines (with the temperature of the positive pressure line being higher)
The fault has been resolved. It was found that the high position of the condensate tank caused a mixture of gas and liquid in the pressure guide tube, leading to problems in measuring the pressure difference. Thank you all for your help! ! ! ! :handshake :handshake
It is likely that there were issues with the data used to select the instruments during the design phase, which led to this situation. Generally, the selection of flowmeters for use is determined by the properties of the medium; if those properties change significantly, it is normal for the flowmeter to give inaccurate readings. On the other hand, it would be abnormal if it provided accurate readings
I originally thought so too, but after replacing the pressure tap, I found it wasn’t that issue.