Blueprint for driving tank?

The diving-tank is refillable at a repairbanch... when i put the diving-tank into the bench it says i have not the blueprint?! I have tried to enable the BP with BlueprintManager but it doasnt work... i think there is no blueprint for that item.

Anyone an idea how it works?

 

it give no blueprints for that at the moment u can find it anywhere

 

I know... but i was wondering that you can refill the tank only with a blueprint^^

But THX for your answer