Diesel fuel tanks are most commonly found in long-haul semi-trucks. But they can also be found in fuel trailers, transfer fuel tanks, auxiliary tanks, fuel tanks for electrical backup generators, agriculture equipments, marine vehicles, and even in biodiesel passenger vehicles.
Because diesel fuel tanks store highly combustible and flammable liquid fuel, it must be built to certain specifications. This is not the place to skimp and save on cost. Look for DOT compliance -- that is the Department of Transportation regulations. Every fuel tank should be pressure tested to ensure that it is leak-proof. Look for this labeling and paperwork. Look for quality welding. You may also want to ask if the tanks have been drop-tested for structural worthiness.
Depending on your application, you need to take into account the design life of the tank. You definitely do not want corrosion to leave your tank leaking while it is still in use.
Don't think of diesel fuel tank as just a tank. There are complex auxiliary devices attached to the tank. Some of which may includes a fuel pump, fuel level indicator, vent cap, emergency vent, security fill cap, and filter.
Typical tank size for trucks can be from 16 inches to 29 inches in diameter and up to 90 inches long. Capacity range from 100 to 150 gallons. But some large tanks can hold up to 200 gallons.
Tanks can be made from mill grade or polished aluminum. The finished can be standard mill grade or high-mirror polished; or it can be custom powder coated for the desired appearance. Special custom diesel fuel tanks can also be crafted.