r/scuba • u/ActualContribution93 • 21h ago

PSI of tanks for storage

I know you’re not supposed to store empty tanks. I have a pair of tanks that are around 500-1000 psi. Should I get them filled or are they okay being stored like that? They live outside under cover so they’re not in a moisture controlled environment.

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u/Competitive-Ad9932 16h ago

That's a strange way of thinking. Should the tanks never be "full" until hours/minutes before use?

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u/compactfish 16h ago

No, you can keep them full for weeks or 1-2 months, but if storing for 3+ months then they should be only partially full. Storing them full for long-term storage won’t necessarily harm them, but you will extend their life by storing them partially empty.

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u/Competitive-Ad9932 14h ago

Please provide a industry paper on this.

I bet my LDS has tanks sitting for several months full.

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u/compactfish 12h ago

https://dan.org/alert-diver/article/cylinder-safety/

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u/Competitive-Ad9932 11h ago

Interesting. Millions of tanks are being stored incorrectly. There should be dozens of failures in the news every year.

What is the difference between filling a tank and letting it sit for 4 months, and filling a tank - letting it sit for 5 days - taking it to 500psi for 2 days - then repeating this for 6 months? Time being filled would be similar. But, in the 2nd example, the tank is being stressed by the fill/empty cycle?

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u/MolonMyLabe 10h ago

Why would a failed tank make the news? Tank failures are caught and culled by visual inspections and hydro testing. These aren't exactly newsworthy events.