Four categories of questions that a conscientious pump buyer ought to consider in the process of selecting a well pump

1. Selecting a Well Pump
Brian Gongol
DJ Gongol & Associates, Inc.
February 2, 2018
Iowa Water Well Association Annual Conference
Altoona, Iowa

2. [Part 1] Categories

3. Vertical turbine pumps

4. Submersible turbine pumps

5. [Part 2] Basic constraints

6. Flow

7. Head

8. Physical shape and size

9. Laws of physics

10. [Part 3] Other limitations

11. Power

12. Hydraulic thrust

13. Downthrust

14. Shaft elongation

15. [Part 4] Additional considerations

16. Power source

17. Discharge head

18. Lubrication

19. Part 1: Categories

20. 1.1 When to choose a vertical turbine

21. Default option for wells

22. Motor accessible for maintenance and repair

23. Alignment maintenance is accessible

24. Upper bearings are accessible

25. Alternate power options are available

26. 1.2 When to choose a submersible turbine

27. Extremely deep wells

28. Crooked wells

29. Sites with surface fooding problems

30. Highly noise-sensitive applications

31. Extreme surface site constraints

32. High risk of vandalism

33. Horizontal pipeline boosters

34. Part 2: Basic constraints

35. 2.1. Flow

36. Usually the one "given" in advance

37. Floor is usually set by demand

38. Ceiling is usually set by well capacity

39. 2.2. Head

40. Combination of static and dynamic factors

41. Static: Water level to pump discharge

42. Static factors: Drawdown at rated fow

43. Dynamic factors: Friction inside column

44. Wild card: Desired pressure at discharge head

45. Simple if a fxed discharge at a fxed elevation

46. More complex: Multiple destinations

47. More complex: Multiple fows

48. More complex: Varying pressures

49. 2.3. Physical shape and size

50. Size of hole available

51. Straightness of the drilled well

52. Larger diameters mean lower friction loss

53. Generally seek the most generous size that fts

54. Constraints at grade level: Footprint

55. Constraints at grade level: Overhead

56. 2.4. Laws of physics

57. Do the bowls ft?

58. Is minimum submergence achieved?

59. Is sufcient NPSH available?

60. Is the total head less than the bowl's limits?

61. Part 3: Other limitations

62. 3.1. Power

63. Hydraulic efciency

64. Drive (motor) efciency

65. Proper grounding is essential

66. Sizing for non-overloading power

67. Motor cooling: Above-grade

68. Motor cooling: Submersible

69. 3.2. Hydraulic thrust

70. Multiply total head by thrust factor

71. 3.3. Downthrust in three easy calculations

72. (a) Hydraulic thrust

73. (b) Weight per stage times number of stages

74. (c) Weight per foot of shaft times length

75. Downthrust = (a) + (b) + (c)

76. 3.4. Shaft elongation

77. Shaft & column stretch due to hydraulic thrust

78. Impellers must not rub against bowls

79. Net elongation = column - shaft elongation

80. Elongation is proportional to thrust

81. Elongation inversely proportional to shaft area

82. Bigger shafts mean less elongation

83. 4.1. Power source

84. Vertical turbine: Usually weather-protected

85. Premium efciency motors now dominant

86. Rate engines carefully for demand

87. 4.2. Discharge head

88. Determined by column, header, and driver size

89. Cast discharge heads usually start cheaper

90. High horsepowers require fabricated heads

91. VFD operations require fabricated heads

92. 4.3. Lubrication

93. Open lineshaft (usually)

94. Pumped fuid provides the lubrication

95. Closed lineshaft is usually lubricated by oil

96. Finally...

97. Certifcations
NSF-61 for safe use in drinking water
ISO 9001 for quality control
Hydraulic Institute for performance standards

98. Materials
No-lead is here to stay
Sometimes stainless steel makes sense

99. Questions?
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Thank you for your attention!

Brian Gongol

DJ Gongol & Associates

515-223-4144

brian@gongol.net

@djgongol on Facebook and Twitter

www.gongol.net or www.djgongol.com

100. Credits
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Saturn from NASA
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https://www.nasa.gov/jpl/cassini/pia18295
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Bedrock aquifers from Iowa Geological Survey
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https://www.iihr.uiowa.edu/igs/silurian-devonian-aquifer/
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San Francisco real estate (retrieved Feb. 1, 2018):
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https://www.trulia.com/real_estate/San_Francisco-California/market-trends/
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Drawdown graph and photo of well in a parking lot from USGS
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https://pubs.usgs.gov/sir/2010/5212/pdf/sir2010-5212.pdf
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Many photos, drawings, and engineering data items were supplied courtesy of
National Pump Co. for the purposes of this presentation
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Other photos and illustrations are the original work of the author and all rights
are reserved