1 Exam Prep NSF/ANSI 50 Equipment for Swimming Pools, Spas ...oneexamprep.com/temp/ansi-nsf-50-100-questions-and-answers.pdf · 1 Exam Prep - NSF/ANSI 50 2012, 2014 & 2015 1 1 Exam

1 Exam Prep - NSF/ANSI 50 2012, 2014 & 2015 1

1 Exam Prep

NSF/ANSI 50 – Equipment for Swimming Pools, Spas,

Hot Tubs and Other Recreational Water Facilities

Questions and Answers

1. The rate of application of water through a filter during backwash in US gallons per minute per square foot of

effective filter area is referred to as:

A. backwash rate

B. backwash

C. filter rate

D. media rate

2. According to Standard 50, a standard rapid rate filter has a design filtration rate not greater than

gpm per square foot for residential pools, spas, or hot tubs.

A. 2

B. 3

C. 4

D. 5

3. The design burst pressure of a pressure service sand-type filter tank shall have a minimum safety factor of:

A. 3:1

B. 4:1

C. 5:1

D. 6:1

4. According to Standard 50, the design collapse pressure of a vacuum service filter tank shall be at

least times the pressure developed by the weight of the water in the tank.

A. 1-1/2

B. 2

C. 2-1/2

D. 3

5. The maximum filtration rate for a diatomite-type filter for a public pool or spa/hot tub (with slurry feed),

shall not exceed gpm per square foot of filter area.

A. 1-1/2

B. 2-1/2

C. 2

D. 3-1/2


6. The filter media for sand-type filters shall not be removed during backwashing at a rate of

gpm per square foot of filter area or the manufacturer's recommended backwash flow rate.

A. 15

B. 20

C. 25

D. 30

7. The design filtration rate of a standard rapid sand filter shall be a maximum of gpm per square foot

for residential pools, spas/hot tubs.

A. 3

B. 4

C. 5

D. 6

8. According to Standard 50, the maximum design filtration rate for a public swimming surface type cartridge

filter shall not exceed gpm per square foot.

A. 2.75

B. 3.75

C. 4.75

D. 3.75

9. Swimming pool motors shall be open drip proof, or totally enclosed and shall be capable of operating a pump

under a full starting load to that of the data plate voltage rating, with a voltage variation of plus or minus:

A. 5%

B. 10%

C. 12%

D. 15%

10. Single-phase motors with a power rating less than horsepower shall have built-in thermal overloads

to provide locked rotor and running protection.

A. 11.5

B. 2.24

C. 2.5

D. 3

11. When testing a multiport valve for leakage, such multiport valve shall not leak more than times

the maximum design flow rate from the return-to-pool port in the 5 min test.

A. .0005 times

B. 30 mL

C. 1.5 times

D. 3 mL


12. The skimmer housing for a recessed automatic surface skimmer shall have an effective weir horizontal

opening of at least inches at the entrance throat for a spa or hot tub.

A. 4

B. 5-1/2

C. 7-1/2

D. 9-1/2

13. Recessed automatic surface skimmers shall have a readily removable and easily cleanable basket or screen,

with maximum openings of square inches.

A. 3.0

B. 0.3

C. 0.05

D. 0.5

14. According to Standard 50, positive displacement pump mechanical feeders operating with a suction lift

of feet of water, at 80% back pressure and 100% of their rated capacity, shall deliver an output rate

within manufacturer guidelines.

A. 2

B. 4

C. 6

D. 8

15. Flow-through chemical feeders shall show no evidence of rupture, leakage, burst, or permanent deformation

when subjected to a hydrostatic pressure of times the manufacturer's maximum pressure rating.

A. 1-1/2

B. 2

C. 2-1/2

D. 3

16. According to Standard 50, it is important that materials used in contact with pool or spa/hot tub (product)

water not impart undesirable levels of contaminants or color to the product water. When extraction testing for

organic contamination is warranted, the exposure water shall have a chlorine level of:

A. 0.0 mg/L

B. 1.0 mg/L + — 0.1 mg/L

C. 2.0 mg/L + — 2.0 mg/L

D. 2.0 mg/L + — 0.2 mg/L


17. Recessed automatic surface skimmers may be installed on the basis of square feet of surface area

per unit or fraction thereof for residential swimming pools.

A. 100

B. 500

C. 600

D. 800

18. Return inlets to recessed automatic surface skimmers should be sized to provide inlet velocity of at

least feet per second for good mixing and proper dispersal of return water.

A. 5

B. 10

C. 15

D. 20

19. Piping for recessed automatic surface skimmers should not be less than 20 gpm per skimmer and should

have a minimum capacity of , of the required filter flow for residential pools.

A. 25%

B. 50%

C. 80%

D. 95%

20. Flow rates should not be reduced for pools, spas, or hot tubs with surface areas of less than 500 square feet

and capacities of less than gallons when using recessed automatic surface skimmers.

A. 64,000

B. 60,480

C. 40,000

D. 16,000

21. According to Standard 50, public spas or hot tubs using diatomite-type filters should have a recommended

turnover rate of not more than:

A. 1/2 hour

B. 6 hours

C. 8 hours

D. 12 hours

22. According to Standard 50 heavily used public pools using sand-type filters should have a recommended

turnover rate of not more than:

A. 1/2 hour

B. 6 hours

C. 8 hours

D. 12 hours


23. Total output of sand-type filters depends on the allowable filtration rate varying from gpm per

square foot depending on use and design.

A. 1 to 10

B. 2 to 15

C. 3 to 25

D. 4 to 30

24. The suction end of the pipe shall be submerged a distance of at least pipe diameters when

verifying performance curve of centrifugal pumps.

A. 5

B. 10

C. 15

D. 20

*25. Ozone process equipment that subjected to pressure shall meet a working pressure of psi.

A. 30 ***This answer is no longer found in the 2014 & 2015 version***

B. 45

C. 50

D. 60

26. Piping intended for use in applications with water at a concentration greater than shall be made from

aluminum brass, nickel-copper alloy or other specified materials.

A. 200 mg/L

B 400 mg/L

C. 600 mg/L

D. 800 mg/L

27. The head loss through the filter after cleaning the media shall not exceed of the initial head loss

through the filter.

A. 50%

B. 75%

C. 125%

D. 150%

28. The actual pump curve shall be within a range of -3% to +5% of the or -5% to +5% of

, whichever is greater.

A. total dynamic head; flow

B. flow; total dynamic head

C. net positive suction head; total dynamic suction lift

D. total dynamic suction lift; net positive suction head


29. The time required to thoroughly backwash the filter system is backwash .

A, Rate

B. Period

C. Cycle

D. Turnover rate

30. The static suction lift is the vertical distance in meters from the centerline of the pump impeller to the:

A. Skimmer level

B. Pool water level

C. 5 foot marker

D. Bottom oldie pool

31. is the time required to recirculate the entire volume of water in a swimming pool, spa or hot

tub.

A. Turnover time

B. Turnaround time

C. Turnover rate

D. Recirculation time

32. Which of the following materials are considered to have acceptable corrosion resistance for general

swimming pool equipment applications and are not required to have a protective coating?

A. concrete

B. SAE 300 stainless steel

C. thermoplastics

D. all of the above

33. Filter tanks designed for vacuum service shall withstand pressure developed by the weight of the water, with

a safety factor of:

A. 1.5

B. 2

C. 2.5

D. 3

34. Commercial vacuum DE filters with disc elements shall have the elements spaced in no less

than inches apart.

A. 1

B. 2

C. 3

D. 4


35. The filtration rate for residential spas with slurry feed for residential use shall be gpm per sq. ft. of

filter area.

A. 2

B. 2.5

C. 3

D.3.5

36. Filter sand shall have a particle size between .

A. .4mm - .55 mm

B. .45mm - .55mm

C. .55mm - 1 mm

D. 1mm - 1.5 mm

37. A high rate sand filter has a design filter rate greater than gpm per sq. ft.

A. 2

B. 3

C. 4

D. 5

38. A baffle is installed in a filter rank to prevent incoming water from flowing directly against the:

A. Connecting pipe

B. Filter surface

C. Effective filter

D. Filter valve

39. When testing a multiport valve for leakage in the filter position and the backwash position, the line pressure

shall be the maximum working pressure and a simulated differential pressure of PSI shall be arranged

between the two ports normally connected to the filter.

A. 9-11

B. 17-19

C. 23-24

D. 29-31

40. The multiport valve manufacturer shall make available a head loss curve for both filter and backwash

positions. Variations from the curve shall not exceed percent when tested at their corresponding flow

rate.

A. 5

B. 10

C. 15

D. 20


41. Skimmer units that may be closed during part of their operating cycle shall he designed to withstand the

negative pressure of Hg.

A. 20

B. 25

C. 30

D. 35

42. In public pools, the equalizer device shall be designed so that during normal operation leakage past the air

lock does not exceed of the design flow rate when ¾ “of the open area of the skimmer is blocked.

A. 5

B. 10

C. 15

D. 20

43. A chemical feeder shall pass a hydrostatic pressure test equal to times the manufacturer’s maximum

pressure rating.

A.1.5

B. 2

C. 2.5

D. 3

44. Dry chemical feeders shall be capable of operating continuous hours at 80 percent of the maximum

pressure and at the maximum output rate recommended by the manufacturer.

A. 1000

B. 2000

C. 2500

D. 4000

45. In flow through chemical feeding equipment, the feeder parts shall meet a hydrostatic pressure

of times the manufacturer’s maximum pressure rating.

A. 1.5

B. 2

C. 2 5

D. 3

46. Skimmers in residential pools should be designed to draw no less than gpm per skimmer.

A. 15

B. 20

C. 25

D. 30


47. The piping for a recessed automatic skimmer should have a minimum capacity of for public pools,

spas, or hot tubs of the required filter flow and it should not be less than 20 gpm per skimmer.

A. 50 %

B. 80 %

C. 75 %

D. 90 %

48. The recommended maximum designed turnover rate for residential swimming pools equipped with DE

filters is not more than hours.

A. 6

B. 8

C. 12

D. 24

49. The head loss through a vacuum service filter operating at the designed flow rate shall not

exceed .

A. 5 Hg

B. 10 Hg

C. The manufacturer’s maximum design head loss

D. 15 Hg

50. Electrolytic chlorine generators shall meet a working pressure of psi or be equipped with a

pressure reducing valve set at the manufacturer’s working pressure.

A. 45

B. 35

C. 40

D. 50

51. The working pressure of a pressure service filter shall be psi or greater.

A. 30

B. 45

C. 50

D. 60

52. Type 1 pool water has conductivity less than or equal to an aqueous sodium chloride solution

of ppm.

A. 1000

B. 1200

C. 1500

D. 1800


53. is hydrated aluminosilicates that contain sodium, potassium, magnesium, and calcium.

A. zeolite

B. diatomaceous earth

C. perlite

D none of the above

54. The vertical distance from the center line of the pump impeller to the pool water level is called:

A. static suction lift

B. vertical suction lift

C. suction lift

D. vertical suction rate

55. Piping made of aluminum-brass shall be used in water applications when the conductivity is greater or equal

to ppm.

A. 300

B. 500

C. 600

D. 800

56. The filter tank and its integral components shall not rupture, leakage, burst, or permanent deformation when

subjected to a hydrostatic pressure equal to times the working pressure for 300 s.

A. 1.5

B. 2

C. 2.5

D. 3

57. The actual filtration area shall be within +/- of the effective filtration area specified on the filter

data plate.

A. 2 %

B. 5 %

C. 8%

D. 10%

58. All controllers, except those labeled to be for swimming pools only, shall be tested at a water temperature

of degrees.

A. 99 + 5 F

B. 100 + 5 F

C. 102 + 5 F

D. 104 + 5 F


59. Bromine generators shall meet a working pressure of psi or be equipped with a pressure

reducing valve set at the manufacturer’s working pressure.

A. 50

B. 45

C. 40

D. 35

60. For swimming pool skimmers, the internal volume of the strainer basket shall be .

A. 140

B. 150

C. 160

D. 175

61. When the skimmer is operating at the maximum design flow rate and the water level is lowered to 2 in.

below the lowest overflow level of the weir, the flow rate through the equalizer line shall be the

maximum flow rate.

A. + 2%

B. + 5%

C. + 8%

D. + 10%

62. Circular weirs shall have a minimum diameter of inches.

A. 3

B. 4

C. 5

D. 6

63. Maximum load amps is the maximum current, in amperes, under the service factor horse power at percent of

its rated voltage.

A. 20

B. 15

C. 12

D. 10

64. A filter shall reduce water turbidity by percent or more when tested in accordance with Annex B.

A. 80

B. 75

C. 70

D. 60


65. The clearance between the filter tank and cartridge(s) shall be at least shall be in.

A. .25

B. .50

C. .75

D. None of the above

66. According to Standard 50, the maximum design filtration rate for a residential swimming surface type

cartridge filter shall not exceed gpm per square foot.

A. 8

B. 3

C. 1

D. 3.75

67. The maximum filtration rate for a diatomite-type filter for a public pool or spa/hot tub (without slurry feed),

shall not exceed gpm per square foot of filter area.

A. 1-1/2

B. 2-1/2

C. 2

D. 3-1/2

68. The design filtration rate of a standard rapid sand filter shall be a maximum of gpm per square foot

for public pools, spas/hot tubs.

A. 3

B. 4

C. 5

D. 6

69. Strainers with an inlet connection with a nominal pipe size of or greater shall have a strainer basket

with a minimum internal volume of 90

A. 1”

B. 1.5”

C. 2”

D. 2.5”

70. Pumps with a rating of HP or less are not required to have a NPSH curve.

A. 5

B. 3

C. 2.5

D. 2


71. Single-phase motors with a power rating less than HP shall have built-in thermal overloads to

provide locked rotor and running protection.

A. 5

B. 3

C. 2.5

D. 2

72. A motor does not require which of the follow information on the data plate:

A. service factor

B. speed

C. frame size

D. warranty information

73. A skimmer shall have a weir that operates freely with continuous action and adjust automatically to

variations in water level over a minimum range of in if an auto-fill pool water level control device is

used when operated at the maximum design flow rate.

A. 5

B. 4

C. 3

D. 2

74. For spa/hot tub skimmers, the internal volume of the strainer basket shall be .

A. 84

B. 66

C. 44

D. 33

75. Electrolytic copper/silver and copper ion generation systems are intended for supplemental treatment of

water. These systems are designated to operate with no less than ppm free chlorine.

A. 0.4

B. 0.5

C. 1.0

D. 3.0

76. Type 2 pool water has conductivity less than or equal to an aqueous sodium chloride solution

of ppm.

A. 1000

B. 1500

C. 3000

D. 6000


77. According to Standard 50, the maximum design filtration rate for a residential swimming depth-type

cartridge filter shall not exceed gpm per square foot.

A. 8

B. 3

C. 1

D. 3.75

78. The maximum filtration rate for a diatomite-type filter for a residential pool or spa/hot tub (without slurry

feed), shall not exceed gpm per square foot of filter area.

A. 1-1/2

B. 2-1/2

C. 2

D. 3-1/2

79. The piping for a recessed automatic skimmer should have a minimum capacity of _____ for residential

pools, spas, or hot tubs of the required filter flow and it should not be less than 20 gpm per skimmer.

A. 80 %

B. 50 %

C. 90 %

D. 75 %

80. The filter tank and its integral components shall not rupture, leakage, burst, or permanent deformation when

subjected to a hydrostatic pressure equal to times the working pressure.

A. 1.5

B. 2

C. 2.5

D. 3

81. Chlorine chemical generators and feeders for pool chlorinator systems should be capable of supplying no

less than lb(s) of chlorine per day, per 10,000 gallons.

A. 1

B. 2

C. 2.5

D. 3

82. To clean a filter by reversing the direction of the flow of water through the filter elements is called?

A. Air assist back wash

B. Backwash

C. Backwash cycle

D. Spray rinse, mechanical


83. The head loss through a filter operating at the design flow rate shall exceed the manufacturer’s design head

loss as long as it is in accordance with Annex B.

A. True

B. False

84. According to Standard 50, motors for centrifugal pumps shall be or totally closed.

A. open-drip proof

B. open-vent-proof

C. energy-efficient

D. semi-closed-drip proof

85. According to Standard 50, a multiport valve and its integral components shall not rupture leak or burst, or

sustain permanent deformation when subjected to hydrostatic pressure of times the working pressure

(Note for students using 2014/2015 version: answer the question based on when initially testing for 300 s).

A. 1.5

B. 2

C. 2.5

D. 3

86. Skimmer housings whose inlets may be closed during part of operating cycle shall not sustain damage when

exposed to a negative pressure of:

A. 10 in Hg

B. 15 in Hg

C. 25 in Hg

D. 50 in Hg

87. For swimming pool skimmers, the total open area in the strainer basket shall be a minimum of .

A. 15

B. 20

C. 25

D. 30

88. Positive displacement pump mechanical feeders shall deliver an output rate that is within +/- 10% of the

delivery specified by the manufacturer when said feeder is operating at with a ft. suction lift at100%

of their rated capacity and 80% back pressure.

A. 2

B. 3

C. 4

D. 6


89. If a pump is designated as a self-priming pump, the true priming time for each shall not exceed minutes

or the manufacturers recommended time, whichever is greater.

A. 6

B. 5

C. 4

D. 3

90. According to Standard 50, the maximum design filtration rate for a public spa depth-type cartridge filter

shall not exceed gpm per square foot.

A. 8

B. 3

C. 1

D. 3.75

91. To test the structural integrity of a recessed automatic skimmer when it is closed, a vacuum is attached to

the skimmer outlet and is held for minutes at an internal vacuum of 25+ 1 in Hg.

A. 2

B. 3

C. 5

D. 6

92. Clear vertical distance in a sand-type filter between the top of the filter media and the lowest outlet of upper

distribution system is called:

A. Freeboard

B. Friction loss

C. Clearboard

D. Open zone

93. Components of mechanical chemical feeders that normally operates under pressure shall show no evidence

of rupture, leakage, burst, or permanent deformation when subjected to a hydrostatic pressure of times

the manufacturer's maximum pressure rating.

A. 1-1/2

B. 2

C. 2-1/2

D. 3

94. In a test to verify the hydrostatic integrity of a pressure service tank filter, after the filter is connected to the

pressure-testing rig and filled with water it is important not to bleed of any air.

A. True

B. False


95. The piping for a recessed automatic skimmer should have a minimum capacity of 50% for residential pools,

spas, or hot tubs of the required filter flow and it should not be less than gpm per skimmer.

A. 10

B. 15

C. 20

D. 25

96. Chlorine chemical generators and feeders for pool chlorinator systems should be capable of supplying no

less than 3 lb(s) of chlorine per day, per gallons.

A. 5,000

B. 10,000

C. 15,000

D. 20,000

97. According to Standard 50, multiport valves shall be designed to have a burst pressure of at least times the

working pressure.

A. 1-1/2

B. 2-1/2

C. 3

D. 4

98. Ozone levels exceeding ppm are not acceptable in the pool, spa/hot tub water.

A. 0.1

B. 0.2

C. 0.3

D. 0.5

99. A total pressure drop in psi of water between inlet and outlet of a component is referred to as:

A. Freeboard

B. Friction loss

C. Negative displacement

D. Head loss

100. For a spa skimmer, the total open area in the strainer basket shall be or greater.

A. 8

B. 10

C. 11

D. 12


1 Exam Prep

NSF/ANSI 50 – Equipment for Swimming Pools, Spas, Hot Tubs and Other Recreational Water Facilities

Answers

2012 2014 / 2015

1. A 2.11 A 2.11

2. D 2.102 D 2.116

3. B 5.1.1.1 B 5.1.1.1

4. A 5.1.2.1 A 5.1.2.1

5. B 5.28 (Table 5.1) B 5.28 (Table 5.1)

6. A 5.3.5.1 A 5.3.5.1

7. C 5.3.9.1 (Table 5.3) C 5.3.9.1 (Table 5.3)

8. D 5.4.10 (Table 5.4) D 5.4.10 (Table 5.4)

9. B 6.10.2 B 6.10.2

10. D 6.10.3 D 6.10.3

11. A 8.5 B 8.5

12. A 9.1.3 A 9.1.3

13. C 9.3.3 C 9.3.3

14. B F.6.1 B F.6.1

15. A 11.3 A 11.3

16. A A.3.3 A A.3.3

17. D K-1 D K-1

18. B K-1 B K-1

19. B Annex K B Annex K

20. D Annex K D Annex K

21. A L.1.1 A L.1.1

22. B L.1.1 B L.1.1

23. C 5.3.9.1 C 5.3.9.1

24. B C.1.4 B C.1.4

25. C 13.3 **** Info removed from 2014/2015 version

26. C 3.6.2 C 3.6.2

27. D 5.1.8 D 5.1.8

28. A 6.6.2 A 6.6.2

29. C 2.10 C 2.10

30. B 2.103 B 2.117

31. C 2.117 C 2.131

32. D 3.3 D 3.3

33. A 5.1.2.1 A 5.1.2.1

34. A 5.2.3.1 A 5.2.3.1

35. C 5.28 (Table 5.1) C 5.28 (Table 5.1)

36. A 5.3.4.1 A 5.3.4.1

37. D 2.5.1 D 2.55

38. C 5.4.2 C 5.4.2

39. C D.2.4(c) C D.3.4.1(c)

40. B 8.6.2 A 8.6.2

41. B 9.1.1 B 9.1.1

42. B 9.4.3 B 9.4.3 (2014), 9.4.4 (2015)

43. A F.1.1 A F.1.1

44. C 10.2.2 C 10.2.2

45. A 11.3 A 11.3 46. B Annex K B Annex K



48. C L.1.1 C L.1.1

49. C 5.1.4 C 5.1.4

50. D 16.3 D 16.3

51. C 5.1.1.1 C 5.1.1.1

52. C 2.70 C 2.80

53. A 2.125 A 2.140

54. A 2.103 A 2.117

55. C 3.6.2 C 3.6.2

56. A 5.1.1.2 A 5.1.1.2

57. B 5.2.1.1 B 5.2.1.1

58. C N.1.2 C N.1.2

59. A 16.3 A 16.3

60. C 9.3.5 C 9.3.5

61. B 9.4.2 B 9.4.2 (2014), 9.4.3 (2015)

62. B 9.2.3 B 9.2.3

63. D 2.58 D 2.65

64. C 5.1.9 C 5.1.9

65. A 5.4.1 A 5.4.1

66. C 5.3.9.1 (Table 5.4) C 5.3.9.1 (Table 5.4)

67. C 5.28 (Table 5.1) C 5.28 (Table 5.1)

68. A 5.3.9.1 (Table 5.3) A 5.3.9.1 (Table 5.3)

69. C 6.3.5 C 6.3.5

70. A 6.6.1 A 6.6.1

71. B 6.10.3 B 6.10.3

72 D 6.10.4 D 6.10.4

73. C 9.2.1 C 9.2.1

74. C 9.3.5 C 9.3.5

75. A 17.1.1 A 17.1.1

76. D 2.70 D 2.80

77. A 5.4.10 (Table 5.4) A 5.4.10 (Table 5.4)

78. B 5.28 (Table 5.1) B 5.28 (Table 5.1)


80. B 5.1.1.2 B 5.1.1.2

81. D J.5.1.1.1 D J.5.1.1.1

82. B 2.9 B 2.9

83. B 5.1.4 B 5.1.4

84. A 6.10.1 A 6.10.1

85. A 8.4 A 8.4 and B.1.4(c)

86. C 9.1.1 C 9.1.1

87. D 9.3.4 D 9.3.4

88. C F.6.5 C F.6.5

89 A C.3.5 A C.3.5

90. B 5.4.10 (Table 5.4) B 5.4.10 (Table 5.4)

91 C E.1.3 C E.1.3

92. A 9.45 A 9.45

93. A 10.5 A 10.5

94. B B1.4 B B1.4

95. C Annex K C Annex K

96. B J.5.1.1.1 B J.5.1.1.1

97. D 8.3 D 8.3

98. A 13.10 A 13.10

99. D 2.4.9 D 2.5.3

100. C 9.3.4 C 9.3.4

Documents

1 Exam Prep NSF/ANSI 50 Equipment for Swimming Pools, Spas ...oneexamprep.com/temp/ansi-nsf-50-100-questions-and-answers.pdf · 1 Exam Prep - NSF/ANSI 50 2012, 2014 & 2015 1 1 Exam