INDUSTRY APPLICATION

Precautions for Using Magnetic Level Gauges to Measure Highly Corrosive Media

When using magnetic level gauges (such as magnetic flap level gauges) to measure highly corrosive media, safety and accuracy depend heavily on comprehensive management—from model selection to maintenance. Key factors include material compatibility, proper installation, and regular maintenance.

magnetic level gauges

 

I. Precise Material Selection: The Foundation of Corrosion Resistance

Material selection is the primary and most critical step. Standard stainless steel (such as 304) corrodes rapidly; therefore, specialized corrosion-resistant models must be selected based on the medium's properties.

Body and Float Materials: For media such as strong acids or alkalis, level gauges with corrosion-resistant linings (e.g., PTFE or F46) or all-plastic construction (e.g., PP, PVC) must be used. PTFE linings are suitable for most highly corrosive liquids, while F46 offers superior protection against highly permeable media (such as liquid chlorine). As the core component, the float must also be made of corrosion-resistant material, such as a fluoropolymer lining.

Operating Conditions: Material selection must account for the medium's temperature and pressure. High temperatures or pressures may exceed the limits of plastic or lining materials, necessitating products with higher temperature and pressure ratings.

System-Wide Compatibility: Materials for all wetted parts—including flanges, gaskets, and bolts—must be compatible with the main body to prevent electrochemical corrosion caused by material mismatch.

II. Proper Installation: The Guarantee of Reliable Operation

Avoid Magnetic Fields: The instrument should be kept away from equipment that generates strong magnetic fields, such as large motors and transformers. Additionally, iron wire must not be used for securing the unit, as this could interfere with magnetic coupling and lead to measurement inaccuracies.

Install Valves: Shut-off valves should be installed between the level gauge and the vessel to allow the medium to be isolated during future cleaning and maintenance.

Maintain Verticality and Stability: The instrument must be installed vertically to ensure the float moves freely. During startup, open the upper valve first, then slowly open the lower valve to allow the medium to flow in steadily, preventing impact damage to the float.

III. Rigorous Operation and Regular Maintenance: The Key to Longevity

Regular Inspections: Periodically inspect the float and the corrosion-resistant lining on the inner wall of the chamber for detachment or cracking, and check whether the float's magnetic strength has diminished. Timely Replacement: Faulty valves, aged gaskets, or damaged indicator flaps must be replaced promptly. It is recommended to replace shut-off valves and flange gaskets annually.

Regular Cleaning: Depending on the nature of the medium, the interior of the float chamber should be drained and cleaned periodically to prevent impurities, crystallization, or sediment from causing the float to jam.

magnetic level gauges

In summary, simply selecting a "corrosion-resistant" magnetic level gauge is not a complete solution for measuring highly corrosive media. Only by effectively combining precise material selection, proper installation, careful operation, and regular maintenance can the instrument's long-term stable, safe, and accurate operation be ensured.

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