Product Manual A
31609 A MTP4000-6000DZV/DZD Operating Manual 71
Section 5 - Troubleshooting
PUMP TROUBLESHOOTING
Symptom Possible Cause
No discharge 1,2,3,4,5,7,8,9,10,17,18,19,20,37
Reduced capacity 2,3,4,5,7,8,9,10,11,17,19,20,21,38,39,40,47
Reduced pressure 5,7,8,11,13,18,19,38,39,40,47
Loss of prime 2,3,4,7,10,11,20,21,22,23
Power consumption excessive, engine runs hot 6,12,13,17,18,19,24,33,34,35,36,37,38,41,42,43,44
Vibration and noise
2,4,9,10,14,15,17,26,27,28,29,30,31,32,33,34,35,36,
39,40,41,42,43,44,48
Seal: excessive leakage, short life, seal housing over-
heating
22,23,25,33,34,35,36,41,44,45,46
Bearings: overheating, short life, noise 26,27,28,29,30,31,32,33,34,35,36,41,42,43,44
Pump overheating, seizes 1,8,9,14,33,34,35,36,41,42,43,44
Corrosion, erosion, pitting, oxidation or other loss of
material
7,8,11,14,15,16
1. Pump not primed
2. Suction line not filled
3. Air pocket in suction line
4. Suction inlet or foot valve
obstructed, insufficiently sub-
merged, or too small
5. System head higher than pump
design head
6. System head lower than pump
design head
7. Insufficient Net Positive Suc-
tion Head (NPSH)
8. Parallel pump application is
incorrect
9. Suction pressure to vapor pres-
sure below minimum
10. Suction lift too high
11. Excess vapor in pumpage
12. Specific gravity of pumpage
housing different than design
13. Viscosity of pumpage different
than design
14. Operation at below rated
capacity
15. Cavitation
16. Electrolysis
17. Impeller obstructed
18. Rotation direction wrong
19. Low speed
20. Air leak into suction line
21. Air leak through mechanical
seal
22. Seal fluid contaminated, hot or
insufficient
23. Seal fluid system not vented
24. High speed
25. Mechanical seal insufficient
26. Bearing housing excessively
cooled
27. Low oil pressure (oil lube bear-
ings)
28. Improper or poor lubrication
29. Lubrication defective
30. Dirt in lubrication/bearings
31. Moisture in lubricant/bearing
housing
32. Lubricant excess
33. Pipe strain
34. Temperature growth
35. Misalignment
36. Coupling improperly installed
37. Impeller installed backwards
38. Worn wear rings
39. Impeller damage
40. Improper balance (after repair)
41. Bent shaft
42. Excessive thrust
43. Rotational element dragging
44. Worn or incorrectly installed
bearings
45. Mechanical seal not properly
set, O-rings damaged or hard-
ened
46. Shaft scored at seal
47. Volute O-ring
48. Foundation not rigid or settled