Differentiate the petroleum product descriptions. If LGN or NGL applies it is different than crude oil. Similar and different issues pertain to products such as gasolines, diesel, kerosines, propane etc.
Lots of dtails apply to the storage tanks with automated level instruments and manual gauging. Some details apply to specific gravity and other fluid properties. Common examples apply to flow measurement, specific gravity, automated and manual shutoff valves, pressure regulators, etc. This stuff enters a facility for cost measurement and is switched to storage places.
Later the storage stuff is pumped to the downstream pipeline or customer loading such as truck and rail tank cars, etc. Again the liquid natural gas would be very different than crude oil, etc.
Did I mention safety related to employee dangers, potential fire or explosion, ...?