1] Suction head ($h_s$) : It is the vertical height of the center lines of the centrifugal pump above the water surface in the tank or pump from which water is to be lifted.

2] Delivery head ($h_d$) : The vertical distance between the center line of the pump and the water surface in the tank to which water is delivered is known as delivery head.

3] Static head ($H_s$) : The sum of suction head and delivery head is known as static head.

$\therefore H_s = h_s + h_d$

4] Manometeric head ($H_m$) : The head against which a centrifugal pump has to work, is called as manometric head.

a) $H_m$ = Head imparted by the impeller to the water - Loss of head in pump.

$= \frac{v_{w2} u_2}{g}$ - loss of head in impeller and casing.

$=\frac{v_{w2} u_2}{g}$ (If loss of pumper is zero}

b] $H_m$ = Total head at outlet of pump - Total head at inlet of pump.

$\therefore$ $(\frac{P_o}{P_g} + \frac{v_o^2}{2g} + z_o) - (\frac{P_1}{P_g} + \frac{v1^2}{2g} + z_i)$

c] $H_m = h_s + h_d + hf_s + hf_d + \frac{v_d^2}{2g}$