[PSUBS-MAILIST] formula

[Alan via Personal_Submersibles]

Hank, 
firstly in the US they refer to scuba tanks by their filled volume ie.
a 80 cu ft tank has 80 cu ft of air when filled. Whereas the rest of the
World tends to refer to the internal volume of the tank in litres ie. a 
10 litre dive tank. 
By 10.7 cubic feet are you referring to internal volume or filled capacity?
Alan


Sent from my iPad

> On 4/03/2017, at 10:30 AM, Cliff Redus via Personal_Submersibles <personal_submersibles at psubs.org> wrote:
> 
> 84.8 lbs assuming a 60F ambient temperature.  See attached derivation.
> 
> Cliff
> 
>> On Fri, Mar 3, 2017 at 2:52 PM, hank pronk via Personal_Submersibles <personal_submersibles at psubs.org> wrote:
>> Alan,
>> I need to know how much  a 10.7 cubic foot tank will extra when pumped up to 1,500 psi.  And how many cubic feet of air will I have when it is pumped up.
>> Hank
>> 
>> 
>> On Friday, March 3, 2017 12:28 PM, Alan via Personal_Submersibles <personal_submersibles at psubs.org> wrote:
>> 
>> 
>> 
>> Hank,
>> air weighs .0807 lbs per cubic foot approximately, depending on temperature.
>> So if you have an 80 cubic foot scuba tank the air weight full is 6.45 lb.
>> A scuba tank is 80 cubic ft at 3000 psi. If you halve the pressure you halve
>> the amount of air & weight. In other words, if you double the pressure you
>> double the weight for a given volume.
>> Let us know what you are trying to calculate if this doesn't help.
>> Alan
>> 
>> 
>> 
>> Sent from my iPad
>> 
>>> On 4/03/2017, at 6:33 AM, hank pronk via Personal_Submersibles <personal_submersibles at psubs.org> wrote:
>>> 
>>> Okay, I am stumped!  can someone give me a formula to calculate the weight of air at a particular psi per cubic foot.
>>> Thank you
>>> Hank
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> 
> <Weight of gas.pdf>
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