The dual color electric contact level gauge is widely used for level monitoring in industries such as power, chemical, and metallurgy due to its intuitive dual color display, high-precision measurement, and multiple protection functions. This article will systematically explain its full lifecycle management methods from four aspects: installation, debugging, daily operation, and maintenance.

1、 Installation specifications: Ensure measurement accuracy and safety

1. Vertical installation and flange connection

The equipment must be installed vertically with an inclination not exceeding±5°To ensure the freedom of the float to rise and fall with the liquid level. During installation, the flange of the liquid level gauge should be connected to the flange of the container through a sealing gasket, and the bolts should be tightened evenly using diagonal tightening method to prevent flange deformation caused by stress concentration. For example, in the monitoring of boiler steam drum liquid level, it is necessary to ensure that the flange centerline coincides with the steam drum axis to avoid the impact of medium flow on the measurement.

2. Electrode installation and sealing treatment

The electrode installation requires applying graphite oil to the threads, sealing the surface with a copper gasket, and gradually tightening until there is no leakage. For high temperature and high pressure scenarios (such as pressure>10MPa）It is recommended to use welding electrodes and ensure that the weld seam is defect free through argon arc welding process. Practice in a petrochemical enterprise has shown that standardized installation can extend the service life of electrodes to8Years or more.

3. Configuration of sewage and connecting pipes

Install at the bottom of the liquid level gaugeDN15The drain valve is connected to the container drain pipeline through a shut-off valve. For easily crystallizable media (such as sulfate solutions), a steam tracing tube should be added to the connecting pipe to prevent the float from getting stuck due to medium solidification.

2、 Debugging steps: calibration and functional verification

1. Slowly inject pressure to avoid impact

During debugging, it is necessary to first open the upper valve and then slowly open the lower valve to allow the medium to gradually flow into the sensor. For pressure>16MPaIn such situations, the injection rate should be controlled within≤0.05MPa/sTo prevent the float from being damaged due to sudden pressure changes. For example, in the commissioning of supercritical boilers, staged injection pressure is used（0-5-10-16MPa）It can effectively prevent the float magnet from falling off.

2. Water resistance setting and critical point calibration

Simulate water resistance using a resistance box (taking desalinated water)100kΩTake tap water10kΩ）Set the critical value through secondary instruments. When setting, it is necessary to ensure that the critical value is between water resistance and steam resistance (such as water resistance)150kΩSteam resistance990kΩWhen, the critical value is set to300kΩ）. After calibration, it is necessary to pass“Simulate liquid level”Verify whether the conversion of red and green light columns is consistent with the actual liquid level.

3. Alarm function test

Short circuit separately/Disconnect the electrode that sets the alarm point position, observe whether the alarm light flashes, whether the buzzer sounds, and whether the relay contacts act. The commissioning record of a certain power plant shows that this step can be excluded90%The above wiring is incorrect.

3、 Daily operation: Standardized use and exception handling

1. Regular discharge and electrode cleaning

Each shift needs to discharge sewage once, and the operation process is to close the lower connecting valve→Open the drain valve→Rinse electrode→Close the drain valve→Open the lower connecting valve. For scaling media (such as circulating water), it is necessary to dismantle the electrodes every month and use10%Soak and clean in hydrochloric acid solution.

2. Quick response to fault codes

When the instrument displays“Err”When coding, it is necessary to check according to the manual:E01For sensor malfunction (check electrode insulation),E03For communication interruption (check)RS485Wiring),E05Abnormal power supply (check)AC220VPower supply). According to statistics from a certain chemical enterprise,85%The fault can be quickly located and resolved through code.

4、 Maintenance strategy: Extend equipment lifespan

1. Seasonal maintenance focus

In winter, it is necessary to check whether the heat tracing pipe is unobstructed to prevent the medium from freezing; In summer, it is necessary to clean the dust on the heat sink to avoid overheating of the secondary instrument. Practice at a northern power plant has shown that seasonal maintenance can reduce equipment failure rates40%.

2. Spare parts management and lifespan warning

Establish inventory of key spare parts such as electrodes and seals, and record the time of each replacement. When the electrode usage exceeds5Annual or display brightness decrease30%At this time, it is necessary to proactively replace it. Through predictive maintenance, a steel plant has reduced the average lifespan of liquid level gauges from6Annual promotion to9Year.

Conclusion

The operation and maintenance of the dual color electric contact level gauge should follow“Accurate installation, standardized debugging, regular maintenance, and rapid response”The principle. By standardizing operating procedures and implementing preventive maintenance strategies, equipment reliability can be significantly improved and the risk of unplanned downtime can be reduced. For enterprises pursuing efficient operation and safe production, mastering these methods is the key to achieving intelligent management of liquid level monitoring.