SUPPLY
The tank trucks that bring fuel from the distributors to the stations can have up to three compartments – one for gasoline, a second for alcohol and a third for diesel. The maximum capacity is 50,000 liters and the discharge, which happens on average every two days, lasts 15 minutes.
GROUNDING
Fuel discharge requires precautions such as grounding, which serves to discharge the electricity accumulated in the bodywork due to air friction with the metal surface of the truck, which can cause shocks. To carry out the operation, a copper cable (the famous ground wire, hehe) is connected to a copper rod in the ground of the gas station.
SUPPLY LINES
These are pipes that connect fuel pumps and tanks, from receiving product from the tank truck to filling cars. They are made of flexible, corrosion-resistant and inert materials – that is, they do not react with fuels
TANK
The underground tank is a carbon steel reservoir with a capacity of up to 30,000 liters. The tanks can have up to three internal compartments to store up to three different products (gasoline, alcohol and diesel) and subcompartments for the varieties (common, additive and premium)
SENSORS
Some stations have electronic monitoring equipment that shows the volume and height of fuel in the tank, the temperature, how much was sold, allowing stock control, etc. It is the sensors installed inside the tank that transmit all this information to a computer.
EMPTY TANK
The pump nozzle «discovers» that the tank is full thanks to a small tube that runs inside the fuel line. Connected to a suction system, this tube “sucks” air from the gas tank. The key to its operation is a flexible diaphragm that has a small hole for outside air.
DIESEL FILTER
Among all fuels used by vehicles, diesel oil has the lowest degree of purity. Therefore, before going to the truck engine, it passes through pressed paper filters, which retain the coarsest impurities (microscopic particles) outside.
GAS COMPRESSOR
Have you seen that big machine at gas stations that sell vehicular natural gas (CNG)? It is the CNG compressor – as the name says, it is used to compress (join) the gas molecules that come from the underground pipeline so that they fit in the cylinders of the cars
FULL TANK
When the tank fills up, fuel blocks the suction tube inlet. It’s like sucking through a straw with the tip capped – the walls of the straw contract from the drop in internal pressure. In the suction tube, the pressure drop causes the diaphragm to expand, touching the pump trigger and “stopping” the flow of fuel.
CLEANING
The gas station floor, you know, is disgusting. To prevent the liquid that comes out of the cars from soiling the city, the stations are surrounded by a channel that takes the oils and water to a separation box. As oil and water have different densities (they don’t mix, oil stays on top), it’s easy to collect them in different boxes
BOMB
The “real” pump is not in the part we see: it is at ground level, and uses a small motor to suck gasoline straight from the underground tanks. In the upper part, a flowmeter sensor transmits to a microprocessor the amount of fuel and the total amount that the customer must pay