Head and Pressure units

<< Click to Display Table of Contents >>

Navigation:  Project design > Pumping systems  > Pumping system procedure >

Head and Pressure units

Previous pageReturn to chapter overviewNext page

In solar pumping systems, Head is usually expressed in units of Level difference [meter or feet]. The pressure at the basis results of the water column weight.

Physically, passing to pressure units involves multiplying the height by the water density (1000 kg/m³) and the gravitation constant  (g = 9.81 m/s²).  And for getting [bar] we have to divide by  100'000 [Pa/bar].

In summary, we have the following equivalences:

 

1 Pa  = 1 N/m²                (mksa basic unit)

1 bar  =  100 kPa        (definition of the Bar)

1 bar  =  10.19 mWater        (passing from level difference to pressure)

1 bar  =  33.44  ftWater        (Idem)

1 bar  =  2088  lbs/ft2        (Pounds/Square feet)

1 bar  =  14.504  PSI        (PSI = Pound/Square Inch)

1 bar  =  0.987  atm

1 bar  =  750.1  torr    or   mmHg

 

1 mWater   =  0.0981 Bar

1 ftWater  =  0.0299 Bar

1 PSI  = 0.069 Bar