23
2026
-
01
What are the common faults of multistage centrifugal pumps?
Multi-stage centrifugal pumps have a more complex structure than single-stage centrifugal pumps. Failures often center on axial force imbalance, inter-stage leakage, and abnormal hydraulic performance.
Multi-stage centrifugal pumps have a more complex structure than single-stage centrifugal pumps. Failures often center on axial force imbalance, inter-stage leakage, and abnormal hydraulic performance. Common faults, their causes, and solutions are as follows:
Insufficient Flow, Low Head
Common Causes:
- Blockage or air leakage in the suction pipeline, leading to insufficient suction in the pump and cavitation;
- Wear, corrosion, or scaling of the impeller, reducing the flow area of the impeller blades;
Worn interstage seal rings causing internal leakage, with medium backflow resulting in pressure loss;
Motor speed below rated value or unstable power supply voltage.
Solutions:
Clean the suction strainer and tighten pipeline flanges to eliminate air leaks;
Disassemble the pump casing to repair or replace worn/scaled impellers;
Replace aged interstage seal rings to ensure seal clearance within standard range;
Check motor power supply and inverter parameters to restore rated speed.
Excessive Pump Vibration and Abnormal Noise
Common Causes:
Failure of axial force balancing device (worn balancing disc, excessive balancing drum clearance) causing shaft movement;
Bent pump shaft or excessive coupling misalignment;
Bearing wear or insufficient lubrication increasing operational resistance;
Impeller imbalance or cavitation caused by high gas content in the suction medium.
Solutions:
Replace worn balance discs/drums and adjust balancing clearance;
Correct pump shaft straightness and realign coupling coaxiality;
Replace damaged bearings and refill with compatible lubricant;
Investigate cavitation causes by reducing suction lift or increasing inlet pressure.
Severe shaft seal leakage
Common causes:
Wear or deformation of mechanical seal moving/stationary rings causing poor seal face contact;
Packing seal aging or improper tightness;
Wear of pump shaft sleeve causing radial runout;
Highly corrosive medium damaging seal materials.
Solutions:
Replace mechanical seal rotating and stationary rings, ensuring clean, scratch-free sealing surfaces;
Replace aged packing and adjust gland tightness (aim for 3-5 drops per minute leakage rate);
Replace worn shaft sleeves and repair pump shaft surface damage;
Select corrosion-resistant seal materials (e.g., fluororubber, silicon carbide).
Excessive Bearing Temperature
Common Causes:
Insufficient lubricant volume, degraded oil quality, or incompatible oil type;
Excessive axial force causing bearings to bear additional thrust;
Over-tight bearing installation resulting in insufficient clearance;
Significant misalignment between pump shaft and motor shaft, increasing bearing load.
Remedial Actions:
Refill or replace with suitable lubricant, maintaining oil level at 1/2 to 2/3 of the dipstick mark;
Inspect and repair the axial balancing device to eliminate excess axial force;
Reinstall the bearing and adjust the clearance to the standard range;
Correct the coupling alignment to reduce radial bearing load.
Interstage Leakage
Common Causes:
Aged or damaged gaskets between intermediate pump casings;
Uneven tightening of pump body connecting bolts causing gaps;
Deformed pump casings resulting in poor seal surface contact.
Remedial Actions:
Replace aged gaskets with temperature- and pressure-resistant materials;
Tighten pump body bolts evenly in a diagonal sequence;
Repair or replace deformed pump casing sections.
Common Series of Wastewater Pumps and Their Core Features
Sewage pumps are centrifugal pumps specifically designed for conveying wastewater, sewage, sludge, and other media containing solid particles, fibers, and suspended solids.
What are the common faults of multistage centrifugal pumps?
Multi-stage centrifugal pumps have a more complex structure than single-stage centrifugal pumps. Failures often center on axial force imbalance, inter-stage leakage, and abnormal hydraulic performance.
The application scenarios for single-stage centrifugal pumps and multistage centrifugal pumps are primarily determined by head requirements and flow characteristics.
Email:
Phone:
Address:
North Guzhu Mountain Industrial Park Yuanquan Town Boshan District Zibo City Shandong Province, China
Copyright © 2026 Zibo Lunkin Oil Pump Manufacturing Co., Ltd. 丨 SEO
独立站建设：中企动力 淄博 外贸Google推广
Hi
Contact us for more preferential prices !