I have a set of oxygen/acetylene tanks that are full and never been used. private owned. I have receipts to prove the exchange. The acetylene tank is 140 cuft. with a test date of 2023. The oxygen tank is the largest one ( 56"x9.75" ) with a test date of 2025 and the valve is sealed as it was exchanged at Vern Lewis Welding Supply in Prescott Valley.