Side mounted magnetic flip column level gauges are widely used for level monitoring in industries such as chemical, power, and food due to their intuitive display, high-precision measurement, and corrosion resistance. However, in long-term operation, equipment may malfunction due to medium characteristics, environmental factors, or improper operation. The following is an explanation from three aspects: typical fault phenomena, cause analysis, and solutions, to help enterprises quickly identify problems and ensure production safety.

1、 The instrument shows no indication when the liquid level rises or falls

Fault phenomenon

The actual process liquid level changes, but the magnetic flip column display shows no action or display error.

Root cause analysis

Float system malfunction

Float leakage or damage: The medium seeps into the interior of the float, causing it to sink to the bottom and unable to rise or fall with the liquid level.

Float demagnetization: Long term use or high temperature environment leads to weakened magnetism, making it impossible to drive the flipping column to flip.

Float stuck: Impurities (such as sediment and crystals) deposited in the measuring tube or installed at an angle, causing the movement of the float to be obstructed.

Magnetic coupling system malfunction

Magnetic loss of flipping column: The magnetic steel inside the flipping column is aging or disturbed by external strong magnetic fields, resulting in magnetic failure.

Accumulation of dirt on the flipping shaft: Residual media can block the flipping shaft, affecting its flipping flexibility.

Solution

Float system processing

Disassemble the measuring tube, check the appearance of the float for damage, and test the magnetic properties of the float with a magnet. If the float leaks or loses magnetism, it needs to be replaced with a float of the same model.

Clean up impurities in the measuring tube: discharge the medium through the drain valve, rinse the tube wall with a soft brush or high-pressure gas to ensure smooth float movement space.

Adjust installation angle: Check the verticality of the liquid level gauge, if the deviation exceeds3°Re calibration is required to avoid the float getting stuck due to tilting.

Magnetic coupling system processing

Replace demagnetized flip column: Use a magnet to attract the flip column and test its magnetism. If the flip column does not respond, the display panel needs to be disassembled to replace the flip column component.

Clean the flipping column shaft: Dip a dust-free cloth in a small amount of industrial alcohol to wipe the shaft body, remove dirt, and apply lubricating grease to restore flipping flexibility.

2、 Instrument leakage occurs

Fault phenomenon

There is a medium leakage at the connection flange, weld or seal of the liquid level gauge.

Root cause analysis

Seal aging: Long term exposure to medium corrosion or temperature changes can cause the sealing gasket to harden or crack.

Installation issue: The flange bolts are not tightened symmetrically, resulting in uneven stress on the sealing surface.

Weld seam defects: During the manufacturing process, the weld seam is not fused or has pores, and it cracks due to vibration during use.

Solution

Replace seals: Remove the leaking flange, clean the sealing surface, and replace the corrosion-resistant gasket (such as PTFE gasket). Tighten the bolts evenly in diagonal order.

Repair welding: If the weld seam cracks, argon arc welding is required for repair welding, followed by pressure testing after welding（1.5Double work pressure, maintain pressure30No leakage in minutes.

Entrusting the manufacturer for repair: For complex leakage problems (such as tank welding), it is recommended to contact the original factory for professional repair to avoid secondary damage caused by self handling.

3、 Chaotic flipping column indication (chaotic magnetic phenomenon)

Fault phenomenon

The color display of the flip column is irregular, and the liquid level indicator fluctuates or is fixed at a certain position.

Root cause analysis

Bubble interference: The vaporization of the medium generates bubbles that enter the measuring tube, forming“Gas phase section”Pushing the float to move abnormally, resulting in magnetic coupling failure.

Changes in medium density: Process parameter adjustments result in changes in medium density, causing a mismatch between float buoyancy and liquid level.

External magnetic field interference: There are devices such as frequency converters and solenoid valves nearby, which generate strong magnetic field interference and flip column magnetism.

Solution

Eliminate bubbles: Install an exhaust valve at the top of the measuring tube to regularly discharge gas; Optimize process conditions (such as reducing temperature and increasing pressure) to reduce medium vaporization.

Adjust float density: recalculate the float specifications based on the medium density, replace the adapted float to ensure that buoyancy corresponds to the liquid level.

Shielding magnetic field interference: Keep the level gauge away from strong magnetic field sources (distance>1Or add a magnetic shielding cover (such as soft iron material) to reduce interference.

4、 Remote signal abnormality

Fault phenomenon

4-20mAThe signal output does not match the actual liquid level, or the signal is interrupted.

Root cause analysis

Malfunction of reed switch: The reed switch contacts are stuck, broken, or loosely fixed, resulting in abnormal signal transmission.

Line problem: Poor contact, virtual soldering, or electromagnetic interference on the signal line, resulting in data distortion.

Unstable power supply: The voltage fluctuation of the power supply exceeds the allowable range (such asDC24V±10%）This affects the operation of the transmitter.

Solution

Replace the reed switch: Disassemble the transmitter housing and test the reed switch's continuity with a multimeter. If it is damaged, replace it with a component of the same specification.

Check the circuit: tighten the signal line connector, replace the shielded twisted pair to reduce electromagnetic interference; Re weld the virtual solder joints.

Stable power supply: Install a stable power supply module to ensure that the power supply voltage is withinDC24V±5%Within the range, avoid voltage fluctuations that may cause signal abnormalities.

5、 Preventive maintenance recommendations

Regular cleaning: discharge pollutants once a month and remove impurities from the measuring tube; Test the magnetic properties of the float with a magnet every six months and replace aging components in a timely manner.

Environmental control: Avoid exposing the level gauge to high temperatures (>450℃）In highly corrosive environments, it is necessary to add insulation or anti-corrosion coatings when necessary.

Operation specification: When put into operation, first open the upper sampling valve, and then open the lower sampling valve to avoid medium impact on the float; When discharging, first close the lower valve and then open the discharge valve to prevent the medium from splashing.

The troubleshooting of side mounted magnetic flip column level gauges requires a comprehensive analysis of process conditions, medium characteristics, and equipment structure. By regular maintenance, standardized operation, and quick response to faults, equipment reliability can be significantly improved, providing stable liquid level monitoring guarantee for industrial production.