As a liquid level measuring instrument based on the principle of magnetic coupling, the magnetic flip column level gauge is widely used in liquid level monitoring in fields such as petrochemicals, food and medicine, and power energy due to its high reliability, strong adaptability, and intuitive display characteristics. This article will provide a detailed analysis from two aspects: working principle and installation specifications.

1、 Working principle of magnetic flip column level gauge

1. Magnetic coupling measurement mechanism

The core of a magnetic flip column level gauge consists of three parts: a floating ball, a magnetic flip column indicator, and a level sensor. The floating ball is integrated with permanent magnet steel inside, and its density is designed according to the specific gravity of the medium to ensure that it always floats on the liquid surface. When the liquid level rises and falls, the floating ball moves synchronously with the liquid level, and its internal magnetic steel drives the external magnetic flip column indicator to flip through non-contact magnetic coupling.

Specific process:

When the floating ball rises, the top magnetic steel attracts the red magnetic piece in the magnetic flip column indicator to flip (red above the displayed liquid level);

When the floating ball descends, the bottom magnetic steel flips the green magnetic plate (green below the displayed liquid level);

The red green boundary is the real-time liquid level height, which achieves visual indication.

2. Signal Conversion and Transmission

Liquid level switch: Install a magnetic liquid level switch at the preset liquid level point. When the float magnetic triggers the switch, output relay signals (such as high level alarm, low level interlock).

Transmitter conversion: The liquid level sensor changes the resistance value through the magnetic force of the float, and is converted into4-20mAStandard current signal for remote monitoring and automated control.
For example, in chemical storage tanks, magnetic flip column level gauges can synchronously output on-site indications andDCSSystem signal, meets“本地+remote”Dual monitoring requirements.

2、 Installation precautions for magnetic flip column level gauge

1. Installation position and direction

Verticality requirement: The liquid level gauge must be installed vertically with an inclination angle≤±3°Otherwise, it may cause the float to get stuck or the magnetic flip column to indicate incorrectly.

Avoid interference sources: Stay away from strong magnetic field equipment (such as motors, frequency converters) and vibration sources (such as pump bodies) to prevent magnetic coupling failure or column flipping misoperation.

Observation angle optimization: The magnetic flip column panel should face the operator to ensure that it15-60Clearly visible within a distance of meters. A case study from a certain refinery shows that tilted panel installation can lead to a shorter visible distance at night60%.

2. Media adaptation and sealing treatment

Medium density matching: The float density needs to be between the medium density and the gas density (such as medium density)1.2g/cm³When selecting the floating ball density0.8-1.0g/cm³）.

High temperature and high pressure sealing:

The process connection flange needs to be selected according to the pressure level of the medium (such asPN16for2.5MPaThe following scenario);

The flange sealing gasket is selected according to the characteristics of the medium (such asPTFEGaskets are corrosion-resistant, and metal wrapped gaskets are resistant to high pressure;

Welded connections are suitable for ultra-high pressure environments (such asPN40Above), it is necessary to ensure that the weld seam is defect free through argon arc welding.

3. Electrical connection and explosion-proof requirements

Signal line shielding:4-20mAThe signal line needs to use twisted pair shielded cables, with the shielding layer grounded at one end to avoid electromagnetic interference causing signal fluctuations.

Explosion proof area selection: in explosive hazardous areas (such asEx dⅡCT4）Explosion proof liquid level switches and transmitters should be selected, and the electrical interface should be ensured to comply withIP65Protection level.

Power stability: The fluctuation of power supply voltage needs to be controlled within±10%Within (such as220V ACVoltage range during power supply198-242V）To prevent damage to the transmitter.

4. Debugging and Calibration Process

Injection speed control: Slowly inject the medium, injection rate≤0.5m/minTo prevent the magnetic steel from falling off due to the impact of floating balls.

Zero point and range calibration:

Adjust the zero point of the transmitter when the tank is empty, so that the output current is4mA；

Adjust the range when the tank is full, so that the output current is20mA；

Repeat calibration3Secondly, the error needs to be≤±1mm.

Verification of column flipping action: Manually move the float up and down to check if the magnetic flipping column flips synchronously and without any jamming.

3、 Typical application scenarios and maintenance recommendations

1. Petrochemical storage tanks

Medium adaptation: For crude oil (high viscosity), a heating jacket type liquid level gauge should be selected to prevent medium solidification; For hydrochloric acid (strong corrosion), Hastelloy alloy float balls should be selected.

Maintenance cycle: Check the flange sealing every quarter and replace the sealing gasket once a year.

2. Food and pharmaceutical industry

Hygiene requirements: Selection316LStainless steel material, surface roughness≤Ra0.8μm, in accordance withGMPauthentication.

Cleaning standard: usingCIP(In situ cleaning) process to avoid contamination caused by disassembly.

Conclusion

The magnetic flip column level gauge achieves high reliability and visualization of liquid level measurement through magnetic coupling technology, and its installation must strictly follow specifications such as verticality, sealing, and explosion-proof. From float density matching to electrical interference shielding, from slow liquid injection debugging to regular maintenance calibration, every step directly affects equipment performance. For enterprises pursuing long-term stable operation, mastering these principles and installation points is the key to ensuring production safety.