Bellows Pump

Principle: Due to the pumping action the air inside the rubber tube is let out from the top causing low pressure inside and so water flows inside. There are one-way valves which prevent the water from flowing back.
Applications:
Regular reciprocating pumps work on the same principle. Valves (one way, 2 way)
These are used in various plumbing systems including flight and mission critical applications
Items Required to make:
Empty film roll bottles (2 Nos.)
Piece of Cycle tube , 3-5 inches
Pins
Sharp Tool to make holes and Fevibond
Straw

Fun Facts to know:
There are foot / paddle operated bellows pumps.

Rotary Pump

Principle: Due to the pumping action the air inside the rubber tube is let out from the top causing low pressure inside and so water flows inside. There are one-way valves which prevent the water from flowing back.
Applications:
Regular domestic pumps used for pumping water from wells, bore wells.
Items Required to make:
Empty film roll bottles (1 Nos.)
Cycle spoke
Crown Cap
Erasers - 2
Sharp Tool to make holes and Fevibond

Fun Facts to know:
Rotary pumps are self-priming and deliver a constant, smooth flow, regardless of pressure variations. They can accommodate high viscosity liquids, high pressures, and high capacities.