How to perform daily maintenance on Dalian chemical pumps?

Dalian Chemical Pump Daily Maintenance Guide

Chemical pumps are core equipment in chemical production processes for transporting corrosive, flammable, explosive, and toxic media. Their stable operation directly affects production safety and efficiency. Dalian experiences cold winters and high humidity, so chemical pump maintenance must consider both media characteristics and local environmental conditions. The following details the key points of chemical pump maintenance from four aspects: daily monitoring, periodic maintenance, fault prevention, and safety regulations.

I. Real-Time Daily Operation Monitoring

Daily maintenance of chemical pumps should focus on operating parameters and the condition of key components, aiming for "early detection and early treatment":

Parameter Monitoring: Record the pump's inlet and outlet pressure, flow rate, medium temperature, and motor current in real time. Pressure fluctuations should be controlled within ±5%. If a sudden pressure drop or abnormal flow occurs, check for inlet pipeline blockage, impeller wear, or cavitation issues. If the motor current exceeds the rated value by 10%, check whether the bearings are lacking oil or if the pump body is stuck.

Seal Inspection: The mechanical seal is crucial for preventing leakage in chemical pumps. Under normal conditions, mechanical seal leakage should be ≤5 drops per minute. If leakage increases or medium drips appear, check for worn sealing faces, insufficient spring tension, or aging O-rings. For gland packing, a slight seepage (10-20 drops per minute) should be maintained to avoid dry friction that wears the shaft sleeve.

Lubrication System: Bearing lubrication requires regular checks of oil level (maintain at 1/2 to 2/3 of the oil level sight glass) and oil quality. If the oil turns black, contains impurities, or becomes emulsified, replace it immediately. For grease lubrication, replenish grease monthly (filling to 1/3 to 1/2 of the bearing cavity) to avoid overheating caused by over-lubrication.

Motor and Vibration: The motor housing temperature should be ≤70°C; if it exceeds 80°C, stop the pump for inspection. Pump body vibration should be ≤0.08 mm. If abnormal vibration occurs, check for coupling misalignment, impeller imbalance, or loose foundation.

II. Periodic Maintenance at Different Intervals

Establish a tiered maintenance schedule based on operating frequency and media characteristics:

Weekly Maintenance: Clean oil stains and dust from the pump body surface, check seal leakage, and verify normal lubricating system oil levels. Inspect the insulation layer of outdoor pumps to prevent winter freezing and cracking.

Monthly Maintenance: Check coupling bolts for looseness and adjust misalignment (radial ≤0.1 mm, axial ≤0.05 mm). Tighten the foundation bolts of the pump body and motor to prevent increased vibration. Clean the inlet filter to prevent impurities from entering the pump body.

Quarterly Maintenance: Dismantle and inspect mechanical seal components, replacing worn sealing rings or O-rings. Measure bearing clearance; replace bearings if radial clearance exceeds 0.15 mm. For pumps handling media prone to crystallization, flush the pipelines with hot water or solvent to prevent crystal blockage.

Annual Maintenance: Completely dismantle the pump body, inspect the impeller and pump casing for corrosion and wear (replace if corrosion depth exceeds 10% of wall thickness). Replace all seals and aged rubber components. Perform an insulation test on the motor (insulation resistance ≥0.5 MΩ) to ensure electrical safety.

III. Key Fault Prevention Measures

Focus on preventing the following issues, considering Dalian's climate and chemical media characteristics:

Cavitation Prevention: Ensure there are no leaks in the inlet pipeline to prevent air ingress. Control the medium temperature below its saturated vapor pressure; for high-temperature media, increase the inlet pressure or reduce the medium temperature. Regularly clean the inlet filter to prevent blockage leading to insufficient inlet pressure.

Crystallization and Freezing Blockage: For media prone to crystallization (e.g., salt solutions), install heat tracing (steam or electric) on the pump body to maintain the medium temperature 5-10°C above its crystallization point. After winter shutdowns, drain the medium from the pump body and pipelines, or circulate antifreeze solution to prevent freezing and cracking the pump casing.

Corrosion Protection: Select appropriate materials (e.g., 316L stainless steel, fluoroplastics) based on media corrosivity, and regularly inspect internal corrosion. For highly corrosive media, apply anti-corrosion coatings inside the pump to extend service life.

IV. Safe Operation Procedures

Chemical pump maintenance must strictly adhere to safety regulations to prevent accidents:

Shutdown Preparation: Before maintenance, disconnect the power supply and hang a "Do Not Close" warning sign. For toxic, flammable, or explosive media, first close the inlet and outlet valves, then purge the pump body with an inert gas (nitrogen) to ensure the medium concentration is below the safe limit.

Personal Protective Equipment (PPE): Wear acid and alkali-resistant protective clothing, rubber gloves, and goggles to avoid direct contact with the medium. If a medium leak occurs, initiate emergency response procedures immediately, evacuate personnel, and ventilate the area.

Maintenance Records: Establish maintenance files, recording the time, parameters, faults, and corrective actions for each inspection. Use data analysis to predict issues like bearing wear and seal aging, enabling preventive maintenance.

Conclusion

Daily maintenance of Dalian chemical pumps must integrate media characteristics with the local environment. Through real-time monitoring, periodic maintenance, and fault prevention, stable equipment operation can be ensured. Scientific maintenance not only extends pump service life but also reduces production safety risks, providing a guarantee for efficient production in chemical enterprises.