Let’s discuss with everyone the issue of the density of the magnetic flap float in liquid ammonia storage tanks
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The magnetic flap level gauge in the liquid ammonia storage tank indicates that there is material inside the tank, but the gauge doesn’t rise; the float also doesn’t drop to the bottom. For example, other level gauges at the site show a level of around 1200, while the magnetic flap gauge reads around 600–700. A magnet can lift the float, so it doesn’t seem to be blocked, and once the magnet is removed, the float drops back down. The density specified in the data sheet for selection was 707 kg/m³, but our process team says that the density of the material varies significantly, ranging between 600–700. We believe this is due to changes in the material’s density. Please help us analyze this situation. If the density is 600, then it should be easier for the float to rise, right? We really feel something isn’t right here.
Additionally, the float is made of 304 material, so it shouldn’t react, right?
The working principle of a level gauge is based on the buoyancy of a float; that is, the density of the float must be less than that of the liquid in order for it to float. If the density of the material is between 600-700 kg/m³, while the set density for the magnetic flap level gauge is 707 kg/m³, this may prevent the float from rising properly in a liquid with a lower density. First, it is necessary to confirm whether the density of the float in the magnetic flap level gauge is indeed suitable for the current density of the liquid. If the buoy density originally designed for the equipment is based on 707 kg/m³, and the density of the liquid at the site drops to 600–700 kg/m³, the buoy may have insufficient lift force due to its high relative density. Secondly, check for any other mechanical obstructions or magnetic issues that might affect the proper display of the magnetic flap. Although you mentioned that it can be attracted by a magnet and fall back down after being released, which indicates that the magnetic components should be functioning properly, it is still recommended to check for any dirt or other debris that might be blocking the float or the magnetic strip. Additionally, tests can be conducted by replacing the float or adjusting its density to see if this improves the accuracy of the level indication. In summary, it is recommended to re-evaluate and select an appropriate float density based on the actual density of the material, while also carefully checking for any foreign objects or structural abnormalities inside the level gauge to ensure that the magnetic flip switch can accurately reflect the true liquid level. .
It’s very likely that the length of the float is incorrect; it’s also possible that the float is missing. If the float is missing, it should sink to the bottom. You can turn off the valve for a moment, remove the bottom flange, and take out the float to check it
Isolate the magnetic flap level gauge, drain the medium from it, open the lower flange of the gauge, and remove the float for inspection. If there are no issues, put the float back in place and push it up to check for any obstruction; if everything is fine, replace the float using a density of 600.