Tanks stored empty for several years, what are the chances they'll pass hydro?

[UTscuba]

I saw a "good" deal on my local classified ads for a pair of luxfer Al 80s complete with bands and manifold. However, I then discovered they've been stored empty (i.e. at ambient atmospheric pressure) for about 8 years.

When I heard that, my initial reaction was to put my wallet away and make my excuses and leave. But on reflection I was wondering if there's a chance they could still be OK.

We're in Utah, so high desert with low humidity, if that matters at all.

any thoughts from anyone?

 

[Scared Silly]

They will be fine. Take them here for re-qual as they are they only testers around SLC: Cylinder Services High Pressure Testing – Rocky Mountain Air Solutions

 

[aviator8]

why not negotiate a price contingent upon passing hydro?

 

[Ben_79]

Ive also walked away from old tanks because of this reason, if they still had air in them I prob would of paid for the tanks and taken a chance with them passing hydro, but the fact they were sitting for years empty was enough for me walk away presuming that the chance of them failing hydro was way to high for my liking.

 

[grf88]

I am unclear what negative effect leaving them empty for an extended period would have, please explain your concerns.

 

[Ben_79]

My thoughts were that if they were sitting under pressure there would be less chance of any moisture being able to enter the tank. I’m only a fairly new diver myself so this presumption is based on what I’ve heard and it’s a theory which made sense to me. I’m keen to hear other thoughts and opinions on this topic.

 

[halocline]

My thoughts were that if they were sitting under pressure there would be less chance of any moisture being able to enter the tank. I’m only a fairly new diver myself so this presumption is based on what I’ve heard and it’s a theory which made sense to me. I’m keen to hear other thoughts and opinions on this topic.

That's a valid concern for steel tanks that could rust with moisture, but not for aluminum tanks.

 

[Scuba Lawyer]

I just had a set of USN steel tanks with an initial hydro dates of 1941 and 1942 (and, according to the original owner, have sat empty since approximately 1959 when last stamped) hydroed. Inside was pretty clean - tiny amount of flash rust. Passed hydro. All depends on the tank and its history. YMMV.

 

[Bob DBF]

I saw a "good" deal on my local classified ads for a pair of luxfer Al 80s complete with bands and manifold. However, I then discovered they've been stored empty (i.e. at ambient atmospheric pressure) for about 8 years.

When I heard that, my initial reaction was to put my wallet away and make my excuses and leave. But on reflection I was wondering if there's a chance they could still be OK.

We're in Utah, so high desert with low humidity, if that matters at all.

any thoughts from anyone?

Depends on the price. In my case, when looking at tanks I bring a light to look inside, not that I inspect tanks for a living but I can tell if it's not worth buying. I also bring a tank and transfill whip to leave pressure in the tank if I don't buy it, not an issue in your case.

I've not seen a correlation between air pressure in the tank and whether it will pass hydro, if the valve is in the tank and closed, even if it leaks.

With Al tanks it is more important to check to see if they are the "bad" alloy, as they are more expensive to maintain, and some shops won't fill them regardless. Is my cylinder made from the "bad" alloy aka AL6351?
In my area, there are a supprizing number of these on Craigslist some are VE and some are not. Some of the sellers are clawless about they are selling, others are trying to pull a fast one.


Bob

 

[snowdog61]

I know of shops that have a standing no-fill policy for anything over 15 yrs, others, no pre-1990 tanks even if you show them the paperwork. I had a 6351 tank that included a fresh VE stamp and hydro but I couldn't find a shop that was informed enough to fill it. Have another 6061 tank from 6-89 that is such a pain to get filled I will likely trash too because most shops again aren't informed/knowledgeable enough even if you show them the paperwork. Just not worth the hassle. Any used tank sale should be contingent on passing hydro & vis period.