About 50 of the most common problems with pumps and pumping systems, along with a simple way to narrow down your investigation of the problem.

1. PUMP TROUBLESHOOTING
Brian Gongol
DJ Gongol & Associates, Inc.
November 4, 2015
Nebraska AWWA Fall Conference
Kearney, Nebraska

2. Quick survey
Are you here for water, wastewater, or both?

3. Sir Arthur Conan Doyle (as Sherlock Holmes)
"Once you eliminate the impossible,
whatever remains, no matter how improbable,
must be the truth."

4. Handout
Pump troubleshooting flowchart

5. All pump problems are either mechanical...

6. ...or hydraulic

7. Secondarily, they are either internal...

8. ...or external to the pump

9. How to tell a mechanical problem
Take away the water

10. How to tell a hydraulic problem
Take measurements

11. Mechanical problems - internal to the pump

12. Bearings

13. Seals

14. Packing

15. Tightness of fit

16. Suction flap valves

17. Debris

18. Internal rubbing

19. Friction

20. Mechanical problems - external to the pump

21. Motors

22. Controls

23. Alignment

24. Balance

25. Transmission

26. Belts

27. Sheaves

28. Couplings

29. Valves (throttling)

30. Valves (isolation)

31. Valves (air-release)

32. Piping

33. Rotation

34. Jay-Z had 99 problems
We've come up with about 50...and this is halftime

35. Hydraulic problems - internal to the pump

36. Recirculation

37. Clearances

38. Wearplate wear

39. Wear ring wear

40. Volute wear

41. Impeller wear
In at least three flavors...

42. Chemical attack

43. Abrasion

44. Cavitation*
Cavitation damage happens inside the pump...
but it's almost always caused outside the pump

45. Hydraulic problems - external to the pump

46. Suction side or discharge side
The two flavors of external hydraulic issues

47. Hydraulic problems - external - suction

48. NPSH
NPSHa (net) = Atmospheric pressure
- vapor pressure
- safety factor
- total dynamic suction lift
- NPSHr for the pump

49. Atmospheric pressure

50. Heat/vapor pressure

51. Air entrainment

52. Air in high spot

53. Turbulence

54. Vortexing

55. Minimum submergence

56. Plugged suction

57. Debris
Never underestimate what a storm can do
...and deposit in your wetwells

58. Horizontal runs

59. Valves

60. Leaks
Not water getting out,
but air getting in

61. Changes to fluid properties
For instance...

62. Gases in solution

63. Surfactants

64. Viscosity

65. Specific gravity

66. Froth/foam/bubbles

67. Hydraulic problems - external - discharge

68. Handout
Engineering data booklet

69. Valves

70. Leaks/breaks

71. Sediment

72. Debris

73. Changes to effective pipe diameter
Caused by...

74. Air

75. Ice

76. Corrosion

77. Scaling

78. Buildup

79. Tools to assist in your investigation

80. Impeller condition: Excess wear

81. Impeller condition: Suction cavitation

82. Impeller condition: Discharge cavitation

83. Shaft breakage

84. Seal failure

85. Strange or unwelcome noises

86. Strange or unwelcome noises
Suction cavitation
Discharge cavitation
Surges
The scream

87. Use all of your available senses (minus taste)

88. Record performance

89. Keep pump curves handy

90. Gauge readings make a huge difference

91. Gauge readings make a huge difference
Look in the direction of change
Was the change gradual or abrupt?
Some are dead giveaways,
others just point in the right direction

92. Gauge case studies

93. Gauge case studies
 The prime that took forever

94. Gauge case studies

95. Gauge case studies
 The prime that took forever
 The hole in the suction line

96. Gauge case studies

97. Gauge case studies
 The prime that took forever
 The hole in the suction line
 The plugged suction

98. Gauge case studies

99. Gauge case studies
 The prime that took forever
 The hole in the suction line
 The plugged suction
 The forcemain failure

100. Gauge case studies

101. Gauge case studies
 The prime that took forever
 The hole in the suction line
 The plugged suction
 The forcemain failure
 The sedimentation
inclination

102. Gauge case studies

103. Gauge case studies
 The prime that took forever
 The hole in the suction line
 The plugged suction
 The forcemain failure
 The sedimentation
inclination
 The bubble, bubble, toil,
and trouble

104. Gauge case studies

105. Gauge case studies
 The prime that took forever
 The hole in the suction line
 The plugged suction
 The forcemain failure
 The sedimentation
inclination
 The bubble, bubble, toil,
and trouble
 The surge-and-slam

106. Gauge case studies

107. Always divide and conquer

108. Questions?
 Thank you for coming!

109. Thank you for your attention!
 Contact us anytime with
questions
 Brian Gongol
 DJ Gongol & Associates
 515-223-4144
 info@djgongol.com

110. References:
 Photo: Mechanic tightening nut (public domain)
 http://loc.gov/pictures/resource/fsac.1a35263/
 All other photos are original work by and copyright reserved
to Brian Gongol