What is a diaphragm pump ? Where is it used ?

A diaphragm is a special type of pump which uses a diaphragm to create pressure.  The diaphragm pump consists of a container with an inlet and outlet valves.  The top of the container is covered with the diaphragm.

The diaphragm is operated by an external mechanism which moves the diaphragm up and down.  When the diaphragm is pulled up, low pressure is created and the liquid is drawn inside the pump.  When diaphragm is pushed down, the fluid inside is pressurized and released through the outlet valve.

A salient feature of the diaphragm pump is that the fluid does not come in contact with the pump components.  Diaphragm pumps are used in the field of medicine where they can be used to construct artificial hearts and in dialysis.

They are also used widely in the food processing industry.

Another common application is in aquariums.  Aquarium pumps which provide air to aerate aquariums are a type of diaphragm pumps.