Regarding the float level gauge for distillation towers

This level gauge is leaking oil quite severely right now; could anyone kind please advise?

The reason for a liquid level reading of 0 is that the liquid level has not yet reached the measurement point for negative values! If there is oil leakage, it depends on what type of float is used; I know there is one type that allows the cover to be opened in order to add filler. But it seems not suitable for use in high-temperature areas such as distillation towers; however, from a structural perspective, if the liquid level display isn’t that important, it can be covered with a box!

1. Principle of operation of the float level gauge: The QV float continuous level indicator utilizes the magnet inside the float, which changes as the liquid level changes; this change affects the resistance in the linkage as well as the voltage-dividing circuit composed of reed switches. The resulting voltage division signal can be converted by a converter into a 4–20mA signal or other standard signals. The smaller the gap in a reed switch, the higher its precision. The indicator can be used in conjunction with other gauges for remote indication; it is a level indicator with a simple principle and excellent reliability. 2. It can display 0 when there is a liquid level: Your distillation tower should be equipped with both a float level gauge and a double-flange level gauge; the zero points for these two gauges are not at the same level. Generally, the 0–100 range on the float gauge should correspond to the 30–70 range on the double-flange gauge, serving as a supplementary reference. Therefore, if the level at the bottom of the tower shows 30% (according to the double-flange gauge), the float gauge might indicate a level around 0. 3. Oil leakage at the valve stem of the float level gauge: It is recommended that you first consult with your instrumentation specialists and fitters to see whether it is possible to take some measures at the valve stem area, to check the connection between the valve stem and its sleeve, or to consider replacing it. I hope this can help you:handshake :handshake :handshake

Thank you. We have two types of level gauges. This unit has been in operation for almost 3 years now, and it might not require maintenance this year. The flow rate of the oil slurry at the bottom of the tower is much lower than before, and it’s not possible to increase that flow rate. We’re concerned that blockages could become severe in the future. The other level gauge also doesn’t work properly, which means that level control will be difficult. I saw earlier that temperature control via the gas and oil pipelines could be used to regulate the liquid level; I’m not sure if this method is effective

Simply put, a float level gauge uses the principle of a buoy to indicate the liquid level. In distillation tower bottoms, two types are generally used: one is double flange type, and the other is float type. A floating ball is still the better choice for use; as long as the temperature at the bottom of the tower is well controlled to prevent coking, it works quite well. If a leak occurs, it is usually at the packing area; if it isn’t secure enough, a small amount of steam can be used for protection, followed by re-packing. (There is some risk.)

If the float ball breaks or falls off, it will not be displayed； If it is DCS control, an over-liquid level may also result in a reading of zero

Controlling the liquid level through temperature control under the large oil and gas pipes is feasible in a short period of time. However, if the problems with the slurry system are not resolved, they will become increasingly severe. It is recommended to increase the slurry circulation rate, or to add feed oil to the bottom of the distillation tower in order to boost the slurry system’s circulation rate; otherwise, shutdown will be imminent.