Conversion Tables and Formulas – by Nelsen Corporation

Volume

1 U.S. Gallon 231.0 in³

0.137 ft³

3.785 liters

.00379 meters³

0.83 Imp gal

0.238 42-gal barrel

1 Imperial Gallon 1.2 U.S. gal

1 Cubic Foot 7.48 U.S. gal

0.0283 meter³

1 Liter 0.2642 U.S. gal

1 Cubic Meter 35.315 ft³

264.2 U.S gal

1 Acre Foot 43,560 ft³

325,829 U.S. gal

1 Acre Inch 3,630 ft³

27,100 U.S. gal

Length
1 Inch	2.54 centimeters

1 Meter	3.28 feet
	39.37 inches

1 Rod	16.5 feet

1 Mile	5280 Feet (1.61 Kilometers)

Capacity

1 Cubic Foot Per Second
(2nd foot) (C.F.S) 449 gpm

1 Acre Foot Per Day 227 gpm

1 Acre Inch Per Hour 454 gpm

1 Cubic Meter Per Minute 264 gpm

1,000,000 Gal. Per Day 595 gpm

Capacity
1 Cubic Foot Per Second (2nd foot) (C.F.S)	449 gpm

1 Acre Foot Per Day	227 gpm

1 Acre Inch Per Hour	454 gpm

1 Cubic Meter Per Minute	264 gpm

1,000,000 Gal. Per Day	595 gpm

Head

1 Pound Per Square Inch (p.s.i) 2.31 ft. head of water

2.04 in. mercury

0.07 kg/cm2

1 Foot of Water

0.433 lb/in2

.855 inc. mercury

1 Inch of Mercury (or vacuum)

1.132 ft of water

1 Kilogram Per Square Cm 14.22 lb/in2

1 Atmosphere (at sea level) 14.7 lb/in2

34.0 ft of water

1 Acre Foot 10.35 meters of water

1 Meter of Water 3.28 feet of water

Head
1 Pound Per Square Inch (p.s.i)	2.31 ft. head of water
	2.04 in. mercury
	0.07 kg/cm2

1 Foot of Water	0.433 lb/in2
	.855 inc. mercury

1 Inch of Mercury (or vacuum)	1.132 ft of water

1 Kilogram Per Square Cm	14.22 lb/in2

1 Atmosphere (at sea level)	14.7 lb/in2
	34.0 ft of water

1 Acre Foot	10.35 meters of water

1 Meter of Water	3.28 feet of water

To Find Capacity of a Tank or Cistern
Diameter of Tank in Feet Squared	x .7854 x	Height of Tank in Feet	x 7.48	Capacity U.S. Gallons

Horsepower

1 H.P. Equals	.746 kilowatts of 746 watts
	33,000 ft lbs per minute
	550 ft lbs per second

H.P. Input Equals	Horsepower input to motor
	1.34 x kilowatts input to motor

Water H.P. Equals	Horsepower required to lift water at

	G.P.M. x total head (in ft.)
	3960

Brake H.P. Equals	H.P. delivered by motor
	H.P. required by pump
	H.P. input x motor efficiency
	1.34 x KW input x motor efficiency
	Water horsepower
	Pump efficiency

	G.P.M x total head (ft.)
	3960 x pump efficiency

	G.P.M x total head (lbs/in2)
	103,000 x pump efficiency

Electric Power

AC	Alternating Current Power

DC	Direct Current

E	Volts

I	Amperes

W	Watts

KW	Kilowatts

Apparent Power	Volts x amperes = Volt amperes

Apparent Power	E I

Useful Power W	E I x P.F.

Power Factor	ratio of useful power to
	apparent power

Power Factor	W
	e i = PF

KW Hr.	Kilowatt Hour

Single Phase	E x I x PF
Power W

3 Phase Power W	1.73 x E x I x PF

Where E	Average voltage between phases

I	Average current in each phase

Electric Power

Efficiency Equals	Power Output Power Input

Motor Efficiency Equals	H.P. Output K.W. input x 1.34

Pump Efficiency Equals	G.P.M. x total head (ft.) 103,000 x B.H.P

Efficiency

Efficiency Equals	Power Output Power Input

Motor Efficiency Equals	H.P. Output K.W. input x 1.34

Pump Efficiency Equals	G.P.M. x total head (ft.) 103,000 x B.H.P

Pressure/Feet of Head

Lbs. Per Sq. In. Feet Head Feet Head Lbs. Per Sq. In.

1 2.31 1 0.43

2 4.62 2 0.87

3 6.93 3 1.3

4 9.24 4 1.73

5 11.54 5 2.17

6 13.85 6 2.6

7 16.16 7 3.03

8 18.47 8 3.46

9 20.78 9 3.9

10 23.09 10 4.33

15 34.63 15 8.66

20 46.18 20 12.99

25 57.72 25 17.32

30 69.27 30 21.65

40 92.36 40 25.99

50 115.45 50 30.32

60 138.54 60 34.65

70 161.63 70 38.98

80 184.72 80 43.31

90 207.81 90 47.65

100 230.9 100 51.97

110 253.98 110 56.3

120 277.07 120 60.63

125 288.62 125 64.96

130 300.16 130 69.29

140 323.25 140 73.63

150 346.34 150 77.96

160 369.43 160 82.29

170 392.52 170 86.62

180 415.61 180 97.45

190 438.9 190 108.27

200 461.78 200 119.1

225 519.51 225 129.93

250 577.24 250 140.75

275 643.03 275 151.58

300 692.69 300 173.24

325 750.41 325 216.55

350 808.13 350 259.85

375 865.89 375 303.16

400 922.58 400 346.47

500 1154.48 500 389.78

1000 2309 1000 433.09

Pressure/Feet of Head

Lbs. Per Sq. In.	Feet Head	Feet Head	Lbs. Per Sq. In.

1	2.31	1	0.43
2	4.62	2	0.87
3	6.93	3	1.3
4	9.24	4	1.73
5	11.54	5	2.17
6	13.85	6	2.6
7	16.16	7	3.03
8	18.47	8	3.46
9	20.78	9	3.9
10	23.09	10	4.33
15	34.63	15	8.66
20	46.18	20	12.99
25	57.72	25	17.32
30	69.27	30	21.65
40	92.36	40	25.99
50	115.45	50	30.32
60	138.54	60	34.65
70	161.63	70	38.98
80	184.72	80	43.31
90	207.81	90	47.65
100	230.9	100	51.97
110	253.98	110	56.3
120	277.07	120	60.63
125	288.62	125	64.96
130	300.16	130	69.29
140	323.25	140	73.63
150	346.34	150	77.96
160	369.43	160	82.29
170	392.52	170	86.62
180	415.61	180	97.45
190	438.9	190	108.27
200	461.78	200	119.1
225	519.51	225	129.93
250	577.24	250	140.75
275	643.03	275	151.58
300	692.69	300	173.24
325	750.41	325	216.55
350	808.13	350	259.85
375	865.89	375	303.16
400	922.58	400	346.47
500	1154.48	500	389.78
1000	2309	1000	433.09

Storage Capacity of Well Casing and Vertical Tanks

Diameter Gal. Per Ft. Diameter Gal. Per Ft.

2 in. 0.16 8.5 ft. 424.5

3 in. 0.37 9 ft. 475.9

4 in. 0.65 9.5 ft. 530.2

5 in. 1 10 ft. 587.5

6 in. 1.5 11 ft. 711

8 in. 2.6 12 ft. 846

10 in. 4.1 13 ft. 993

12 in. 5.9 14 ft. 1151

16 in. 10.4 15 ft. 1322

18 in. 13.2 16 ft. 1504

20 in. 16.3 17 ft. 1698

24 in. 23.5 18 ft. 1904

30 in. 36.7 19 ft. 2121

36 in. 52.9 20 ft. 2352

42 in. 72 21 ft. 2591

48 in. 94 22 ft. 2845

54 in. 119 23 ft. 3109

60 in. 147 24 ft. 3384

66 in. 177.8 25 ft. 3672

72 in. 211.5 26 ft. 3971

78 in. 248.2 27 ft. 4283

84 in. 287.9 28 ft. 4606

90 in. 330.5 29 ft. 4841

96 in. 376 30 ft. 5288

Storage Capacity of Well Casing and Vertical Tanks

Diameter	Gal. Per Ft.	Diameter	Gal. Per Ft.

2 in.	0.16	8.5 ft.	424.5
3 in.	0.37	9 ft.	475.9
4 in.	0.65	9.5 ft.	530.2
5 in.	1	10 ft.	587.5
6 in.	1.5	11 ft.	711
8 in.	2.6	12 ft.	846
10 in.	4.1	13 ft.	993
12 in.	5.9	14 ft.	1151
16 in.	10.4	15 ft.	1322
18 in.	13.2	16 ft.	1504
20 in.	16.3	17 ft.	1698
24 in.	23.5	18 ft.	1904
30 in.	36.7	19 ft.	2121
36 in.	52.9	20 ft.	2352
42 in.	72	21 ft.	2591
48 in.	94	22 ft.	2845
54 in.	119	23 ft.	3109
60 in.	147	24 ft.	3384
66 in.	177.8	25 ft.	3672
72 in.	211.5	26 ft.	3971
78 in.	248.2	27 ft.	4283
84 in.	287.9	28 ft.	4606
90 in.	330.5	29 ft.	4841
96 in.	376	30 ft.	5288

Flow of Water/Gravity or Tank Pressure

The approximate flow of water in GPM through a length of pipe due to the force of gravity can be easily determined by the formula:D x 100 devided by L

Determine the vertical distance in feet (D) between the pipe inlet and the pipe outlet. Multiply this distance by 100 and divide that amount by the total length of the pipe in feet (L).

Refer to the appropriate friction loss table for the size and type of pipe. Read down the appropriate column to the number of feet as determined by the formula above. Read across to the left to determine the approximate flow rate through the pipe. The flow at the lower end of the pipe will be at zero pressure.

Example

A 300' length of 1" plastic pipe runs from an inlet point to a point to discharge 40 feet lower. The approximate flow rate would be 40 x 100 divided by 300 = 13.3. Referring to the friction loss tables gives a flow rate between 14 and 16, or about 15 GPM.

For pressure tanks the formula is the same, except that the pressure in the tank should be converted to vertical feet of head and added to the vertical distance if any. Again the flow at the end of the pipe will be at zero pressure.

Conversion Tables and Formulas - by Nelsen Corporation

Length 1 Inch2.54 centimeters 1 Meter3.28 feet 39.37 inches 1 Rod16.5 feet 1 Mile5280 Feet (1.61 Kilometers)

Capacity 1 Cubic Foot Per Second (2nd foot) (C.F.S)449 gpm 1 Acre Foot Per Day227 gpm 1 Acre Inch Per Hour454 gpm 1 Cubic Meter Per Minute264 gpm 1,000,000 Gal. Per Day595 gpm

To Find Capacity of a Tank or Cistern Diameter of Tank in Feet Squaredx .7854 xHeight of Tank in Feet x 7.48Capacity U.S. Gallons

Flow of Water/Gravity or Tank Pressure

Example

Length

1 Inch 2.54 centimeters

1 Meter 3.28 feet

39.37 inches

1 Rod 16.5 feet

1 Mile 5280 Feet (1.61 Kilometers)

Capacity

1 Cubic Foot Per Second
(2nd foot) (C.F.S) 449 gpm

1 Acre Foot Per Day 227 gpm

1 Acre Inch Per Hour 454 gpm

1 Cubic Meter Per Minute 264 gpm

1,000,000 Gal. Per Day 595 gpm

To Find Capacity of a Tank or Cistern

Diameter
of Tank
in Feet
Squared x .7854 x Height
of Tank
in Feet x 7.48 Capacity
U.S. Gallons