Magnetic flap level gauge
Thread Content
There are liquefied petroleum gas tanks in the factory, and on-site magnetic flap level gauges are used to measure the liquid level. The density of the material used for the floats is appropriate, yet the readings from these magnetic flap level gauges are inaccurate, with large errors. After the gauge is put into use, it shows a level of two meters; after a few minutes, the level starts to drop slowly, and once it reaches one meter, it begins to rise again, eventually reaching two and a half meters. This situation occurs frequently. Could you please explain this to me? Thank you!
The gas-liquid phase transition causes the float to rise
A magnetic flap, in essence, is just a communicating vessel – nothing special about it. The fact that the float can move up and down indicates that there is no problem with it. You need to determine the actual liquid level inside the tank; you can use a temperature gun to measure the temperature gradually from the bottom of the tank upward. Generally, a temperature difference will be detected at the top of the liquid surface, allowing you to confirm the liquid level and see if it matches what the magnetic flap indicates. If the explanation above is clear, you can also use a magnet or wrench on the magnetic plate connection tube to check and confirm the correct position of the float; don’t rely on the surface of the plate, as it can be inaccurate at times
You need to confirm whether a communicating vessel has been formed: the upper and lower tubes must be connected
Check the temperature inside the tank to see if it is caused by the gas-liquid transition
Check whether there is a difference between the temperature inside the tank and the ambient temperature; if so, it is likely that vaporization or liquefaction is causing the inaccurate liquid level
Try brushing it from top to bottom with a magnet.
It must be caused by the vaporization of a liquid
Uncertainty is inevitable when a gas-liquid two-phase state exists