# Air Tank Question



## nodakksjs (Sep 24, 2010)

Ok, So I'm needing some assistance with pneumatics, but not regarding stage props but a air horn. 

Now say I bought a portable air tank with a max psi of 125. How far can one safely over fill said tank, before it turns into a bomb.

I'm asking this not out of pure ignorance (well sort of) but from what I've read/been told is that and air tank with a max psi of 125 can safely hold 160-170psi before rupturing. This leeway is added for air temperature differences.

Please tell me if I'm off base with this information.

My hope is getting the tank at 150psi safely and say max temperature in mid summer being 130f inside of a car. (but more than likely I would drop the psi to 130-140 in the summer so I don't kill my self(if above information is correct))

Sorry for asking this here but I just can't find any good sources of information or professionals to talk to.

Thanks in advance for any assistance.


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## Dark Lord (Jul 25, 2007)

Generally regular compressors only hit 150-170 psi.Most things like tanks are under rated for safety reasons, when you tell the general public the real top rating, someone will always push that & create problems.....The other important factor is the age of air tank,fittings,gauges. Metals stress over time. I rarely hear one popping, but there have been times when a weld opened up or the valve or a fitting failed..........obviously you add heat to it will cause extra stress from heat expansion, but not by much. Safely I would run no more than 150 & try to keep out of the sun like in a car ( or ice it down a lil ) unless it is a special tank rated for 200+ psi
As for your spare air tank, I would safely keep it to 125 max psi & not leave it in any hot places (too long)


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## Redsand187 (Sep 18, 2010)

Most air tanks have a pressure release valve that goes off around 150 psi.


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## rottincorps (Jun 1, 2008)

WHY!.........where in a car would you place it ......if you get in a accedent could it be ruptured so think about it


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## nodakksjs (Sep 24, 2010)

Thanks for all the assistance, and I think I'll keep the psi around 135-140 and Redsand187 you are correct there is a safety release valve that goes off at 150. So even if an extra 10-15 psi is to much that should save my ass.



> WHY!.........where in a car would you place it ......if you get in a accident could it be ruptured so think about it












That's what I drive, and the tank is in the back of the trunk









(old tank that leaked, but you get the point)

So if someone hits me from behind hard enough to crush all of that frame I think the tank will be the least of my problems.


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