Pump characteristic curves are usually in height – feet or meters – and a conversion to pressure scales commonly used in gauges – such as psi or bar – may be necessary.
Converting Head to Pressure
turning the head into foot for pressure in psi
The characteristic curves of the pumps in foot head can be converted to pressure – psi – by the expression:
p = 0.433 h SG (1)
Where
p = pressure (psi)
h = head (ft)
SG = fluid specific gravity
turning the head into metros for pressure in bar
The characteristic curves of the pumps in metros head can be converted to pressure – bar – by the expression:
p = 0.0981 h SG (2)
Where
h = head (m)
p = pressure (bar)
Converting the load to metros for the pressure in kg/cm 2
The characteristic curves of the pumps in metros head can be converted to pressure – kg/cm 2 – by the expression:
p = 0,1 h SG (2b)
Where
h = head (m)
p = pressure ( kg/ cm2 )
Converting Pressure to Head
As pressure gauges are usually pressure calibrated – psi or bar – conversion to commonly used pump heads may be required – such as foot or meters.
converting pressure into psi to head in foot
h = 2.31 p / SG (3)
Where
h = head (ft)
p = pressure (psi)
converting pressure into bar to head in metro
h = p 10.197 / SG (4)
Where
h = head (m)
p = pressure (bar)
Conversion of pressure into kg/cm 2 to height in metros
h = p 10 / SG (4b)
Where
h = head (m)
p = pressure (kg/cm 2 )
Example – Pump Head Conversion – foot – in Pressure – psi
The pressure - psi – of a water pump operating at a head of 120 feet can be calculated with eq. 1 like:
p = 0.433 (120 pes) (1)
= 52psi _
Example – Pressure Conversion – psi – for Pump Head - foot
the load on foot of water column can be calculated from the pressure of 100 psi with eq. 3 like:
h = 2.31 (100 psi) / (1)
= 231 feet
Where specific gravity of water = 1 .
Head Water Feet in psi
| Head (ft) |
Essential factors to consider when choosing a pneumatic diaphragm pump (psi) |
|---|---|
| 1 | 0,43 |
| 2 | 0,87 |
| 3 | 1,30 |
| 4 | 1,73 |
| 5 | 2.17 |
| 6 | 2,60 |
| 7 | 3,03 |
| 8 | 3,46 |
| 9 | 3,90 |
| 10 | 4,33 |
| 20 | 8,66 |
| 30 | 13,0 |
| 40 | 17,3 |
| 50 | 21,7 |
| 60 | 26,0 |
| 70 | 30,3 |
| 80 | 34,7 |
| 90 | 39,0 |
| 100 | 43,3 |
| 120 | 52,0 |
| 140 | 60,6 |
| 160 | 69,3 |
| 180 | 78,0 |
| 200 | 86,6 |
| 250 | 108 |
| 300 | 130 |
| 350 | 152 |
| 400 | 173 |
| 500 | 217 |
| 600 | 260 |
| 700 | 303 |
| 800 | 346 |
| 900 | 390 |
| 1000 | 433 |
Source: https://www.engineeringtoolbox.com/pump-head-pressure-d_663.html
