The Free On-line Aquaculture Dictionary

Hydram Pump Calculations
Formulae Table

Hydram Pump - Factors required for pump selection

1. The difference in height between the water source and the pump site (called vertical fall).

2. The difference in height between the pump site and the point of storage or use (lift).

3. The quantity (Q) of flow available from the source.

4. The quantity of water required.  

5. The length of pipe from the source to the pump site (called the drive pipe).  

6. The length of pipe from the pump to the storage site (called the delivery pipe).  

Once this information has been obtained, a calculation can be made to see if the amount of water needed can be supplied by a ram. 

The formula is: D=(S x F x E)/L 

Where:

D = Amount delivered in litres per 24 hours.

S = Quantity of water supplied in litres per minute.

F = The fall or height of the source above the ram in meters.

E = The efficiency of the ram (for commercial models use 0.66, for home built use 0.33 unless otherwise indicated).

L = The lift height of the point of use above the ram in meters.

 
The table below solves this formula (the result in the table is expressed in litres delivered in 24 hours) for rams with efficiencies of 66 percent, a supply of 1 litre per minute, and with the working fall and lift shown in the table.  For supplies greater than 1 litre/minute, simply multiply by the number of litres supplied.

Working Fall (m)

Lift - Vertical height to which water is raised above ram (m)

 

 

 

5

7.5

10

15

20

30

40

50

60

80

100

125

 

1.0

144

77

65

33

29

19.5

12.5

 

 

 

 

 

 

1.5

 

135

96.5

70

54

36

19

15

 

 

 

 

 

2.0

 

220

156

105

79

53

33

25

19.5

12.5

 

 

 

2.5

 

280

200

125

100

66

40.5

32.5

24

15.5

12

 

 

3.0

 

 

260

180

130

87

65

51

40

27

17.5

12

 

3.5

 

 

 

215

150

100

75

60

46

31.5

20

14

 

4.0

 

 

 

255

173

115

86

69

43

36

23

16

 

5.0

 

 

 

310

236

155

118

94

71.5

50

36

23

 

6.0

 

 

 

 

282

185

140

112

93.5

64.5

47.5

34.5

 

7.0

 

 

 

 

 

216

163

130

109

82

60

48

 

8.0

 

 

 

 

 

 

187

149

125

94

69

55

 

9.0

 

 

 

 

 

 

212

168

140

105

84

62

 

10.0

 

 

 

 

 

 

245

187

156

117

93

69

 

12.0

 

 

 

 

 

 

295

225

187

140

113

83

 

14.0

 

 

 

 

 

 

 

265

218

167

132

97

 

16.0

 

 

 

 

 

 

 

 

250

187

150

110

 

18.0

 

 

 

 

 

 

 

 

280

210

169

124

 

20.0

 

 

 

 

 

 

 

 

 

237

188

140