parviz,
Some things to note about concrete tanks..
- Usually more expensive than coated, welded steel
- Piping inlets/outlets must be reinforced
- Must be coated internally
- Difficult to inspect
- Difficult to pump from ( pump suction must be at the bottom of the tank)
Some things to think about when storing crude oil
- You will collect water at the bottom of the tank
- tank must have special coating
- Tank will have air emmissions
Good Luck !!
MJC