Even the sturdiest tanks and vessels become susceptible to oxidation as they age. Regular and proper maintenance helps keep them in good shape, yet oxidation still occurs, releasing ferrites into the liquid stream. Ferrites not only alter the quality of the product, but also have a detrimental effect on instrumentation reliant on magnetism, hurting its accuracy and reducing its lifespan.

Ferrites are compounds made of iron oxide and one or more additional metals. They are attracted to other magnetic pieces, such as the magnet found in the float of magnetic level gauges and indicators, and can cause the float to become lodged inside the pipe. Because of this, ferrite buildup can result in inaccurate level readings in indicators and magnetically activated transmitters.

Solution: Magnetic Traps

Particularly in aging plants, it is very difficult to completely eliminate oxidation and the associated ferrite formation within the process itself. WIKA offers magnetic traps to minimize this effect. When installed directly in the process line, between the magnetic level indicator and the vessel, the magnetic trap catches ferrites, taking them out of the liquid stream and preventing them from affecting the measuring instrument. The trap has a set of powerful magnets that attract ferrites before they can reach the magnetic level indicator. Isolation valves allow the operator to easily remove the dirtied magnets from the trap, perform preventive maintenance, and then reinsert the cleaned magnets to continue running the process with very little downtime.

Older equipment, especially those tanks and vessels made of mild steel found in chemical and refining plants, get extra benefits from magnetic traps. They not only ensure proper level readings, but also keep the product purer. A major oil refining company in Texas, for example, installed magnetic traps to extract the ferrites that were being released into the process in some of the distillation towers it uses for styrene production. The magnetic traps isolated the particles, allowing them to be removed. This helped maintain the purity and quality of the product with less extensive daily testing and cleanup.

Magnetic traps are reliable, cost effective, and low maintenance. They are a good solution for offsetting the effects of ferrite buildup, maintaining accuracy, and extending the life of magnetic level indicators.

WIKA experts work individually with each customer to identify the best solution for each process. They have years of field experience optimizing level measuring in a variety of applications. Contact them today.

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