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View Full Version : Full HPA Tank in Storage???



Shingo
10-16-2007, 01:35 PM
I have a 45k/68cu Fiber Wrapped tank holding about 3k psi of air in it.... It's had this air since Jan/Feb 2007. I didnt realize that it's full until the other night when I looked at the gauge.

My concern is that the walls of the tank are now weak from holding this pressure for so long. And using it will result in an explosion where I will loose a limb or kill me... Should I be worried? Overall the tank looks perfect. And I think I dont have to hydro test until mid 2009.

Should I be concerned?


Shingo

grEnAlEins
10-16-2007, 01:42 PM
I have a 45k/68cu Fiber Wrapped tank holding about 3k psi of air in it.... It's had this air since Jan/Feb 2007. I didnt realize that it's full until the other night when I looked at the gauge.

My concern is that the walls of the tank are now weak from holding this pressure for so long. And using it will result in an explosion where I will loose a limb or kill me... Should I be worried? Overall the tank looks perfect. And I think I dont have to hydro test until mid 2009.

Should I be concerned?


Shingo
Better safe than sorry man... get it hydro tested... I would

BlueDragonX
10-16-2007, 01:44 PM
I wouldn't be too worried, but if you want to be safe about it, definitely have it hydrotested.

georgeyew
10-23-2007, 02:44 PM
The regulator would blow before the walls on the tank gets weak. Don't waste your $$. I keep my tanks filled all the time (not the same air for 10 months) and do not have a problem.

Dend78
10-23-2007, 02:54 PM
ive had tanks filled for a long time a year plus on one tank dont worry about the walls of the tank, it will be just fine

Thordic
10-23-2007, 03:01 PM
Yeah, keeping tanks filled isn't a big deal. Don't worry about it.

Spider-TW
10-23-2007, 03:05 PM
Tanks are designed within the stresses required for material creep. What kills them is the fill and discharge cycle, more like a spring fatigue failure than a simple stress failure. If it hasn't been heated or beaten, I would not be worried about it coming apart (more than any other bottle in hydro). 10 months is not long for the structural parts. Your seals may have set up though. Those quarter turn on/offs on the bottle don't have very good lives. A pin valve should be ok.

What we really need is a test cycle based on number of full fills, but that would be a real pain for us and the DOTs (DsOT?, govmint).

If you read the hydro criteria, they should really get failed under hydro by getting too stretched out (that cubic inch displacement on the label), not by catastrophic failure. Aluminum work hardens easily and once it stretches out it gets weak.

ThePixelGuru
10-23-2007, 05:35 PM
I'd rather store my tanks full than empty, because if it's pressurized then junk from the outside can't get in and screw up my tank.

Madmox
10-24-2007, 09:18 PM
The tanks are made to be stored with pressure in them. In fact you should never let the tank totally empty as that is when moisture can be introduced to the interior of the tank causing it to corrode. Unless it is up for hydro don't worry about getting it done and as someone said earlier tanks fail due to the charge and discharge process. I have seen SCUBA tanks that have held a full fill for 20 odd years. I don't think you have a problem and thats from a Compressor Tech and SCUBA instructor's point of view.

Madmox

NoLifeLeft
10-24-2007, 10:00 PM
The tanks are made to be stored with pressure in them. In fact you should never let the tank totally empty as that is when moisture can be introduced to the interior of the tank causing it to corrode.
Madmox


What he said. :)