Troubleshooting processes for pumps

1. PUMP TROUBLESHOOTING
Brian Gongol
DJ Gongol & Associates, Inc.
September 4, 2019
Iowa WEA Operators Conference
Newton, Iowa

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

3. All pump problems are either mechanical...

4. ...or hydraulic

5. Secondarily, they are either internal...

6. ...or external to the pump

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

8. How to tell a hydraulic problem
Take measurements

9. Mechanical problems - internal to the pump

10. Bearings

11. Seals

12. Packing

13. Tightness of fit

14. Suction flap valves

15. Debris

16. Internal rubbing

17. Friction

18. Mechanical problems - external to the pump

19. Motors

20. Controls

21. Alignment

22. Balance

23. Transmission

24. Belts

25. Sheaves

26. Couplings

27. Valves (throttling)

28. Valves (isolation)

29. Valves (air-release)

30. Piping

31. Rotation

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

33. Hydraulic problems - internal to the pump

34. Recirculation

35. Clearances

36. Wearplate wear

37. Wear ring wear

38. Volute wear

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

40. Chemical attack

41. Abrasion

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

43. Hydraulic problems - external to the pump

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

45. Hydraulic problems - external - suction

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

47. Atmospheric pressure

48. Heat/vapor pressure

49. Air entrainment

50. Air in high spot

51. Turbulence

52. Vortexing

53. Minimum submergence

54. Plugged suction

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

56. Horizontal runs

57. Valves

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

59. Changes to fluid properties
For instance...

60. Gases in solution

61. Surfactants

62. Viscosity

63. Specific gravity

64. Froth/foam/bubbles

65. Hydraulic problems - external - discharge

66. Handout
Engineering data booklet

67. Valves

68. Leaks/breaks

69. Sediment

70. Debris

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

72. Air

73. Ice

74. Corrosion

75. Scaling

76. Buildup

77. Tools to assist in your investigation

78. Impeller condition: Excess wear

79. Impeller condition: Suction cavitation

80. Impeller condition: Discharge cavitation

81. Shaft breakage

82. Seal failure

83. Strange or unwelcome noises

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

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

86. Record performance

87. Keep pump curves handy

88. Gauge readings make a huge difference

89. 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

90. Gauge case studies

91. Gauge case studies

The prime that took forever

92. Gauge case studies

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

94. Gauge case studies

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

96. Gauge case studies

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

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

The sedimentation
inclination

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

The bubble, bubble, toil,
and trouble

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

The surge-and-slam

104. Gauge case studies

105. Always divide and conquer

106. Questions?

Thank you for coming!

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

108. 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