Pumps ....

What is the purpose of pump ?
Transfer of liquid from one place to another place (e.g. water from an underground aquifer into a water storage tank)
Circulate liquid around a system (e.g. cooling water or lubricants through machines and equipment)

What all are the components of pumping system ?
Pumps
Prime movers: electric motors, diesel engines or air system
Piping, used to carry the fluid
Valves, used to control the flow in the system
Other fittings, controls and instrumentation
End-use equipment,(Examples include heat exchangers, tanks and hydraulic machines)


What is Head ?
Pressure is needed to pump the liquid through the system at a certain rate. This pressure has to be high enough to overcome the resistance of the system, which is also called “head”. The total head is the sum of static head and friction head.

What is Static Head ?
Static head is the difference in height between the source and destination of the pumped liquid. Static head is independent of the flow.
Static head consists of:
Static suction head : resulting from lifting the liquid relative to the pump center line. The static suction head is positive if the liquid level is above pump centerline, and negative if the liquid level is below pump centerline (also called “suction lift)
Static discharge head : the vertical distance between the pump centerline and the surface of the liquid in the destination tank

What is Friction Head ?
This is the loss needed to overcome that is caused by the resistance to flow in the pipe and fittings.
It is dependent on size, condition and type of pipe, number and type of pipe fittings, flow rate, and nature of the liquid.
The friction head is proportional to the square of the flow rate as shown in the figure.
A closed loop circulating system only exhibits friction head.

What are the characteristics that determine the performance of pump ?
The head and flow rate determine the performance of a pump.