Proper way to store tanks?

[Hoosier]

I thought you took a PSI VIP class?? And yes it is for the fire safety..nothing to do with diving.

Actually, as I recall, they mentioned 500 psi, not in full......
So, I would like to see what rationale is behind when someone contended it in full.

It seems that Doc Harry's article covered pretty much all question.....

 

[oxyhacker]

Good point. Scuba air is much, much drier than ambient air, and will actually, as the tank is cycled, remove any moisture that might have found its way in last time the tank was opened. Which is why I like to break down and inspect my tanks in the spring. If I open a tank which is not going to see use immediately afterwards, or especially, will go into storage, I like to flush it, by blowing in a few hundred PSI, then draining it down almost all the way, before putting a few hundred back in for storage.

I wouldn't store a tank which had been exposed to ambient air then revalved, without any pressure in it - the pressure inside is the indicator that the valve has remained closed. Also, if the valve is inadvertently opened, and someone hears the hiss, they will close it, where if they don't hear anything, they probably will never notice it was opened.

The only problem with this scenario is that you are not leaving your tanks empty, you are leaving them full of room air that has moisture content.

 

[Tommymac]

When tanks leave the factory, they are shipped empty. If there was enough moisture in ambient air to seriously rust the tank, I would have 14 rusty tanks, most of which are from the 60's.

In a perfect world no compressor would ever put moisture in a tank.

A couple years ago I bought a set of Sportsways 42's at a garage sale. They were purchased new in 1962, manfacture date on the tanks was 1961. The guy never got certified so he used them once after which they collected dust in his garage (in Minnesota). He used them to fill tires etc, and they had been empty for at least 15 years. They were mint inside.

I live in the midwest and have never had a tank develop any rust when stored empty. The only time I have seen moisture in any of my tanks is when they just got back from hydro.

I wish I had an extra tank that I could send you. I'd ask you to store it even with the valve open. It would be a neat experiment. You don't live in the rain forest do ya?

 

[halocline]

I wish I had an extra tank that I could send you. I'd ask you to store it even with the valve open. It would be a neat experiment. You don't live in the rain forest do ya?

I wish you did too! Around here it seems like it hasn't rained in about a year. I don't know how quickly a tank would rust from being exposed to ambient air, I just know that if you take the valve off and allow the tank to stand open for a while, then close it, you're definitely closing it filled with air that has some humidity.

 

[SparticleBrane]

Here in NC during the summer it is not infrequent to have 90%+ humidity. Leaving open steel cylinders in a garage would be unwise.

 

[Tommymac]

I could easly set aside a tank and leave it sit to see what happen's, but I have been doing that exact type of off season storage since I started diving in 1962. I would like to see a more official test done by a magazine. I find it interesting that when a tank is filled with water at a hydro, its later dried out with ambient air, sometimes thru a glorified hair dryer. I built a tumbler and have tumbled many tanks. Always dried them with a home made dryer using ambient air. I think if ambient air is good enough to dry out a completely wet tank, you can store with ambient. IMHO diving has a few old wives tales that never go away. This I think is one of them.

 

[DA Aquamaster]

Back in western South Dakota where 10% humidity was not uncommon and where anything over 30% was considered "humid" you could leave a bag of potato chips open for a week and they'd still be crispy.

If you can't do that where you live, you do not want to leave your tanks open to ambient air.

Also, if you leave them open in a climate where the temperature changes significantly from day to night, the inside of the tank will collect condensation when it cools down at night and the presence of liquid water will rust your tank in short order.

The 'wives tales' surrounding leaving tanks open are based on near worst case scenarios and may not apply everywhere, but why take the chance? put a valve on the tank and close it or at least slap a piece of duct tape over the opening to reduce any air exchange.

 

[crpntr133]

When tanks leave the factory, they are shipped empty. If there was enough moisture in ambient air to seriously rust the tank, I would have 14 rusty tanks, most of which are from the 60's.

All 8 of my Worthington's had a desecant plugs in them when shipped from the factory, or for that matter the dive shop. Others may be different.

 

[Ed Palma]

This is true -- North Carolina doesn't normally get earthquakes. Hurricanes, however...

I was considering coming up with a restraint system but haven't done it yet.

I saw this thread the other day, and it got me thinking about the outcome of your tanks... Did they fall during yesterday's earthquake?

 

[Sonic04GT]

I saw this thread the other day, and it got me thinking about the outcome of your tanks... Did they fall during yesterday's earthquake?

Hahahahaha. I forgot about this thread.