This is a series where I share my interesting work/cases as an EI (Electrical Instrument) technician that I do with my team. The purpose of this series is for me to learn and evaluate my actions.
Series 1. May 15th, 2024
In the primary brine area, one of the level gauges in the Brine tank had a problem. The issue was that the magnet indicator level gauge was stuck at ±50% when the Level Transmitter showed 60%. We used a smaller magnet to locate the magnet inside the level gauge. Additionally, the tank was hot, with a temperature around ±60°C.
To determine whether the level gauge or the level transmitter was the problem, we considered two points:
1. The operator could adjust the tank's level. If the operator lowered the level of the tank and the magnet inside the level gauge did not move, it was clear that the magnet was stuck.
2. Because the brine tank was hot, when the magnet stayed at ±50% of the tank but the heat of the level gauge felt like it was at 60%, we knew that the magnet was stuck. We came up with this idea because at 70% the level gauge was cold.
Once we were certain that the magnet was stuck, we tried to drain it and found that the brine inside the level gauge came out black. After flushing it with water, we removed the magnet and found it to be dirty with blackness on top, which led us to believe that this was the reason it was stuck. After cleaning it, we tested the level gauge with confidence, but unfortunately, the level gauge magnet was still stuck in the same place.
Clearly, we made a mistake. The mistake was that we did not look inside the level gauge; we were too focused on the magnet and neglected to check the condition inside the level gauge itself.
The reason the magnet was stuck was because there was a bump inside the level gauge at 50% that intrupt the magnet to float upwards. The level gauge was coated with a material called Teflon, and we could see this bump clearly from the picture below. I believe that the bump occurred inside the level gauge due to the deformation of the Teflon.
A question arose: why was there a bump inside this level gauge?
Check comments below if you want to see my opinions!