Technical

Possible causes

Aspiration failure

1. The pump has not been filled before operation; 2. The suction pipe of the pump is not full of fluid; 3. The net suction head is not enough; 4. There is too much air or gas in the fluid

5. There is no flowing air cavity in the suction pipe; 6. The air leaks into the suction pipe; 7. The air enters the pump through the stuffing box or mechanical seal; 8. There is air in the source of the sealing fluid

9. The water seal pipe is blocked; 10. The packing ring in the stuffing box is not installed properly; 11. The suction pipe is not completely immersed in the liquid; 12. There is eddy current at the suction inlet

13. When the pump is running, the suction valve is closed or partially closed; 14. The suction filter is blocked; 15. The suction pipe is blocked; 16. The friction resistance of the suction pipe is too large

17. Impeller clogging

Other hydraulic problems

18. Wrong rotation direction; 20. The instrument is not calibrated; 21. The impeller diameter is smaller than the specified; 22. The impeller diameter is larger than the specified value;

23. When the pump is running, the discharge valve is closed, and the bypass is not opened; 24. Run the pump under the minimum flow; 25. The friction loss of the system is greater than the calculated value

26. The maximum pressure head of the system is greater than the design head of the pump; 27. The maximum pressure head of the system is less than the design head of the pump; 28. The pump is operated in an excessive flow state (for a specific low-speed pump)

29. Operate the pump at too low flow rate (for specific high-speed pump); 30. The specific gravity of the fluid does not conform to the design conditions; 31. The viscosity of the fluid does not conform to the design conditions

32. The internal operating clearance is too large due to wear; 33. The leakage pipeline of the balancing device is blocked;

Mechanical fault generality

34. Poor alignment; 35. Insufficient rigidity of foundation; 36. Missing foundation bolts; 37.