tank weight

Hello, Can anyone tell me the precise weight of an 11-liter aluminum tank at 200 bar and 50 bar? I saw someone on quora posted images of the scales reading for such a tank with 3000 psi and 1000 psi. 3000 was around 17.7 kg and 1000 psi was around 16.2 kg. The reason I'm asking this is...

Has anyone seen/used anything like this? I bought it recently thinking I could use it to turn an AL80 into a steel tank weight wise... or something. (Slapping own hand—must resist dive shop used gear shelf!)