Pump laws

Pumps are governed by certain laws which relate the rotation speed of the impellor to the volumetric flow rate, pressure rise, and power consumption.


If the impeller size is a constant but the impeller speed changes:

Law4.gif (1341 bytes)
Law2.gif (1392 bytes)
Law3.gif (1420 bytes)

where the subscripts 1 and 2 refer to two different operating points for a given pump.


If the impeller speed is constant but the impeller size changes:

Law5.gif (1239 bytes)    
Law6.gif (1285 bytes)
Law7.gif (1333 bytes)

where Di is the impellor diameter and the subscripts 1 and 2 refer to two different impellors for a given pump.