Pump characteristics (Parameters):

a. Capacity:

• It is the volume of water pumped per unit time.
• Generally measured in lit/sec and denoted by a small capacity.
• Sometimes stated as lit/min or lit/hr and large capacities in m³/sec.

b. Head:

• It is the work done on a unit weight of water by the pump.
• Expressed in meter and denoted by H.

c. Suction lift:

• It exists when the source of water supply is below the center line of the pump.

d. Static suction lift:

• It is the vertical distance from the free section water level to he center line of the pump.

e. Total suction lift:

• It is the sum of static suction lift, friction and entrance losses in the suction piping.

f. Suction head:

• It exists when the source of water supply is above the center of the pump as is the usual case a turbine operated pump.

g. Static suction head:

• It is the vertical distance from the center of the pump to the free level of water to be pumped.

h. Total suction head:

• It is the vertical distance from the center line of the pump to the free level of the liquid to be pumped minus all friction losses in suction pipe and fitting, plus any pressure head existing on the suction supply.

i. Static discharge Head:

• It is the sum of static discharge head, friction losses and exit losses in the discharge piping plus the velocity head and pressure head at the point of discharge.

j. Total discharge head:

• It is the sum of static discharge head, friction losses and exit losses in the discharging piping plus the velocity head and pressure head at the point of discharge.

k. Pressure head:

• It is the pressure exerted in m of water, in a closed vessel from which the pump takes its suction or against which the pump discharges.

I.e. H_p = P/w

Where,

H_p = pressure head, m

P = Pressure inside the vessel, Kg/m²

W = specific weight of water, Kg/m³

l. Total head:

• It is the energy imparted to water by the pump.
• It is the sum of total discharge head and total suction lift when suction head exit.

m. Velocity head:

• It is the pressure, expressed in meters of water, required to create the velocity of flow.

Mathematically,

H_v = V²/2g

Where, H_v = velocity head, m

             V = velocity of water through the pipe, m/sec.

             g = acceleration due to gravity, m/sec.