Troubleshooting Rotor Pumps: Still Can’t Locate Recurring Faults? Have You Encountered These Five Common Issues?

Behind continuous production line operation, every transfer equipment performs an irreplaceable function. Rotor pumps deliver media through precise meshing between rotors and pump cavities, and their operating status directly determines smooth connection of upstream and downstream processes. Many staff tend to disassemble pumps for inspection immediately upon alarms, yet they ignore the systematic troubleshooting path covering valve status, medium properties and electrical protection.

-Bonve Pump Cam-style Twin Rotor Pump-

1.No medium discharges from the pump outlet. This problem is usually not caused by pump damage itself, but abnormal external conditions. First verify whether the motor rotation direction matches the marking on the pump body-if the rotation direction is reversed, the suction port and discharge port will swap directly, so no pressure can build up at the outlet. Second check whether manual valves on suction and discharge sides are closed, which is an easily overlooked simple error. Besides, excessively low inlet liquid level or insufficient supplementary pressure will deprive the pump of liquid suction capacity. Even though rotor pumps have self-priming capability, this capability has clear limits. A safety valve failing to close tightly due to slag trapped on its sealing surface or excessively high medium viscosity that stops rotors from grabbing materials can also lead to zero flow.

2.Outlet flow is obviously lower than the rated value. This type of fault is relatively hidden and needs item-by-item verification. Low inlet pressure will trigger cavitation, so inspect feed pipelines for blockages or air ingress. Long-term rotor wear enlarges meshing gaps and increases internal leakage, which reduces actual discharge volume. Poor sealing of the safety valve creates internal backflow, and substandard motor speed leads to flow reduction. If the medium viscosity is too low, recheck the recommended operating range of this pump model and replace the pump if necessary.

3.Abnormal vibration or shrill noise emerges during operation. Excessive coupling misalignment and dried-out grease are the most common triggers. Residual gas trapped inside the pump cavity that cannot be fully vented generates irregular gasping-like sounds. Motor malfunctions, reducer gear wear, eccentric shaft seal installation, bent pump shafts or bearing wear will all be reflected through vibration readings. Do not rush to increase load when facing such faults; conduct on-site sound detection and vibration measurement first to narrow down fault scope step by step.

4.Operating current remains high and may even trigger protection trips. Blocked outlet pipelines or insufficient valve opening cause sharp backpressure rise, which is the primary factor for overcurrent. When the actual medium viscosity exceeds the pump’s applicable range, resistance against rotor movement increases accordingly. Over-tight assembly of the shaft seal gland, stuck worn bearings and motor winding faults all manifest as abnormal current. On site, inspect outlet valve opening first and judge viscosity changes combined with medium temperature.

5.Sudden pump shutdown during operation. Common causes include external power failure, motor overload protection activation and broken coupling shear pins. Ultra-high outlet pressure triggers interlock shutdown, indicating material blockage in downstream pipelines. Foreign objects or hard particles trapped in the pump cavity, as well as seized shafts and bearings due to oil shortage, count as inherent equipment faults and require pump disassembly for inspection.

Bonve pump always adheres to the philosophy of "Wholeheartedly Making Good Rotor Pumps," committed to providing global customers with customized conveying and mixing solutions. If you have technical inquiries, selection needs, case references, or other cooperation intentions related to Bonve rotor pumps, please feel free to contact us.  

Service Hotline: 0574-87588986 13586591794  

Official Website: www.bvpumps.com  

Business Email: market@bonvepumps.com  

We look forward to working with you to drive efficiency and innovation in industrial fluid transmission with precision technology.