Pump Head
The term head is commonly taken to mean the difference in
elevation between the suction level and the discharge level of the liquid being
pumped.
Suction Lift
A Suction Lift means the liquid level is below the
center line of the pump suction. The term static suction lift is used to
describe the vertical distance from the pump center line down to the free level
of the liquid source below the pump.
Suction Head
The static suction head exists if the liquid source is
located above the center line of the pump. This may also be referred to a
flooded suction. The term static suction head is used to describe the vertical
distance from the center ine of the pump up to the free level of the liquid
source above the pump.
Friction Head
This is the pressure drop on both inlet and discharge sides
of the pump due to frictional losses in fluid flow.
Static head
Static head is simply the difference in elevations of the
outlet and the inlet point of the system or height of the supply and
destination reservoirs. Static head is independent of flow and pipe diameter.
The static head is the potential energy of the system.
Dynamic Suction head
The dynamic suction head includes static suction head minus
friction head and velocity head.
Dynamic Suction lift
The dynamic suction lift includes static suction lift,
friction head loss and velocity head.
Velocity Head
Velocity head is the head needed to accelerate the liquid.
Knowing the velocity of the liquid, the velocity head loss can be calculated by
simple formula, Head = V²/2g,
in which g is acceleration due to gravity