A Dispenser is a device that dispenses liquid fuel such as gasoline or compressed natural gas while measuring the amount dispensed. Other names for dispensers are pumps, gas pumps or fuel pumps.
Modern fuel pumps are divided into two parts…
There is a great history of Gas Pumps here.
A modern fuel pump is logically divided into two main parts.
- An electronic “head” containing an embedded computer to control the action of the pump. It drives the pump’s displays, and communicate to an indoor sales system.
- Secondly, the mechanical section which is a ‘self-contained’ unit has an electric motor, pumping unit, meters, pulsers and valves to physically pump and control the fuel flow.
The actual pump may be sealed and immersed inside the fuel tanks on a site. This is a submersible pump.
In modern pumps, the major variations are in the number of hoses or grades they can dispense, the physical shape, and the addition of extra devices such as pay at the pump devices and attendant “tag” readers. SOURCE: Wikipedia