| What are you talking about?
The date has to be there. It lets the owner / filler / whoever know when the tank was MFG so they can get a good idea of its condition.
It does not mean it has to be hydro tested. When tanks are manufactured, they are dated. If your new 9 oz is aluminum and is under 2 inches OD..follow what everyone has said in this thread. If it is under 2 inches, it does not need hydro testing. |