Centrifugal Pump Data Calculation

Changing of revolving speed:

a, The revolving speed of the pump can be altered so as to adjust the head and capacity for various requirements.

b, Method to change the speed to change the pulley of the pump, or to change the gears of a gear drive equipment, or to select motive power of different speeds.

c,After the speed(n) changed, the capacity (Q), head(H) AND brake power (P) are also changed. They are linked by three following relationships:

Q1/Q2=N1/N2

H1/H2=(N1/N2)²

P1/P2=(N1/N2)³

d, When the speed of the pump is increased, the brake power is increased by cubic form, the suction head is decreased. And the lif of the pump is shortened. To increase pump speed to much will probably cause abnormal events. Therefore. it should be very carefully considered to increase the speed.

e, When the speed is decreased by a large amount, the pump utulization will be decreased. So it should be avoided as possible to run the pump at a too low speed.