Some pumps use mechanical action and there are some three kinds of pumps which are gravity pumps, displacement types, and direct lift pumps.
Pumps use rotary or reciprocating methods and energy to do the work by moving the fluid and the sources of energy may comprise of industrial plants, medical applications such in medical field where a microscopic is used and they are diverse in sizes, may use wind power, engines, electricity or they may be manual.
Pumps may be used to pump water from ponds, aquarium filtering, wells, fuel injection, cooling towers, natural gas, pumping oil and for energy industry and when used in the health field they are used as biochemical methods in manufacturing and developing medicine, as well as for body parts replacement such as the penile prosthesis and artificial heart replacement.
There are also steam pumps, gravity pumps, velocity pumps, impulse pumps and positive displacement pumps and they mainly use two methods of pumping that is centrifugal and positive displacement.
The pumps may actually be submerged into the water and the pumping is done by external forces and a displacement pump makes the water to move by catching a certain amount of the water and then forcing it to get trapped in the discharge pipe and the suction side decreases the cavity of the discharging side.
A pump has safety valve which is very necessary and can be external or internal and the manufacturer ensures that the safety valves or internal relief is present because this is used a safety precaution and the return suction line is also provided for increasing the safety.
Highly viscous fluids have higher rates of flow that assist in increasing the viscosity while others have close clearances in the rotating pump which makes it to do the rotation slowly but a speed that is steady.
Very high speeds might make the fluid to cause some erosion which after a long time causes the enlargement of clearances and this makes some liquid to pass through easily and by doing so the efficiency is reduced.
Diaphragms restrict the motion of the fluid to only move to the desired direction and once the pressure is too much in the chamber the inward pressure forces the plunger to open and the fluid is discharged in very high velocity into the delivery pipe.
Kerr Pumps may be used in pumping water into swimming pools, pumping air into bouncing castles which children use them to play, putting gas into cylinder, filling huge tanks with water for irrigation and even more devices which are used fir car sparing and house paining where air is used instead of a brush.
Special pumps are utilized for ejecting water at very vast speed to put off the fire and in the worst of cases the armed forces and police also use special trucks mounted with huge water tanks to emit high jest of water from special jets to disperse rioters so read more about pumps.
For further reading/watching, please visit https://www.youtube.com/watch?v=678NKpSpL9I .