As a precision fluid conveying equipment widely used in fields such as chemical engineering and water treatment, the stable operation of electromagnetic diaphragm metering pumps is crucial to the production process. However, due to factors such as working conditions, operating methods, and equipment aging, this type of pump often experiences various malfunctions. The following provides a systematic explanation of the fault symptoms, causes, and solutions:
1、 Unable to start or difficult to start
-Power supply abnormality: Check if the power cord is broken, if the fuse is blown, and use a multimeter to measure if the voltage is within the rated range (usually 220V ± 10%). If loose wiring terminals are found, they need to be re tightened; If the controller displays an error code, refer to the instruction manual to troubleshoot.
-Mechanical blockage: Disassemble the pump head to check if the diaphragm is deformed and if the connecting rod is corroded. If the diaphragm is damaged and causes hydraulic oil leakage, it is necessary to replace the original diaphragm and clean the pump chamber; When the connecting rod is stuck, you can use a file to polish the rust and apply lubricating oil.
-Pipeline blockage: Close the inlet and outlet valves, remove the filter and one-way valve for high-pressure flushing. For crystalline media, it is recommended to soak them in hot water or solvents before cleaning.
2、 Unstable or insufficient traffic
-Inhalation end issue
-Excessive suction: The installation height should be lower than the allowable value (generally ≤ 5m), and high viscosity media should be supplied with liquid by reverse injection.
-Valve sealing failure: Disassemble the ball valve to check the elasticity of the spring and the integrity of the rubber gasket. If the wear exceeds 0.5mm, it needs to be replaced.
-Cavitation phenomenon: Raise the tank level or install an exhaust valve, and if necessary, add a stabilizer to the inlet pipeline.
-Discharge end issue
-Insufficient back pressure: Install a pressure balance valve on the outlet pipeline and adjust it to the required head for the process.
-Check valve leakage: Disassemble and clean the valve core, grind the sealing surface, and replace it as a whole when it is severely worn.
-Travel setting error: The stroke length should be calibrated through the controller panel, and the error should be controlled within ± 1%.
3、 Abnormal vibration and noise
-Basic looseness: Use a level to calibrate the installation plane of the pump body, and the torque of the foundation bolts should reach the specified value. When the shock absorber pad ages, it should be replaced with acid and alkali resistant nitrile rubber material in a timely manner.
-Component wear: Check the radial clearance of the bearing. If it exceeds the standard value, replace the deep groove ball bearing with a higher precision level. Excessive gear mesh clearance can cause periodic abnormal noise, and the side clearance needs to be adjusted to a reasonable range.
-Cavitation corrosion: Drill holes in areas prone to cavitation for exhaust, or use a double diaphragm structure to enhance resistance to cavitation.
4、 Leakage fault
-Static seal failure: If the flange gasket is aging, a PTFE coated gasket can be used, with a surface roughness Ra ≤ 3.2 μ m. Anaerobic adhesive sealing is recommended for threaded connections.
-Dynamic seal damage: Pay attention to the direction when replacing the lip seal ring, with the opening facing the high-pressure area. The chrome plating treatment on the surface of the shaft sleeve can extend its service life.
-Diaphragm rupture: Regularly check the cleanliness of hydraulic oil, and the particle size NAS level should be ≤ 8. It is recommended to replace the diaphragm component every six months.
5、 Overheating protection contact
-Overload operation: Check if the actual working current exceeds the rated value, and switch to the backup pump unit when overloaded.
-Poor heat dissipation: Remove dust from the motor fan cover and ensure that the ventilation rate is ≥ 90% of the design value. For continuous operation conditions, it is recommended to install a forced cooling system.
-Inconsistent medium characteristics: When transporting high-temperature liquids, silicone based diaphragm materials should be used, and conventional nitrile rubber is suitable for temperatures not exceeding 120 ℃.
Through the above systematic investigation and targeted treatment, common faults of electromagnetic diaphragm metering pumps can be effectively solved. It is recommended to establish a preventive maintenance mechanism, regularly verify instrument parameters, and replace vulnerable parts in a timely manner to ensure long-term stable operation of the equipment.