Can anyone help figure out this tank size?

[kev2809]

i got a tank for free today from a buddy of mine thats owns a wrecker service. he parted out an older 18 wheeler and gave me a tank from it. it has 13 ports lol...but its bigger than my 5 gallon. doesnt come with any mounting brackets so i will have to figure something out!

from side to side its 27 1/4". top to bottom is about 12". front to back (deep) is about 11 1/2".

heres a few pics..

[Shane]

you can use the formula of V=Pi*r²*h to find cubic inches then convert to gallons

Pi=3.14159
r=11.75/2 (11.75 is the average DIAMETER, so we must divide by 2 to get the radius then square)
h=27.25" (length)

V=3.14159*(11.75/2)²*27.25"
V=2954.827 in³

1 in³ = 0.00432900433 US gallons

2954.827 in³ = 10.9925 gal APPROX.

[kev2809]

now thats math!

lol..thanks for looking that up for me. looks like im going to keep it. 11 gallons of air should be good!

[skip99]

don't forget that air is compressed. so, 11 "gallons" usually measured in cubic feet, varies on the pressure it is kept at. in other words.. you can use a tank 1/2 the size at double the pressure..

the amount of air contained in the tank varies with the pressure..

it's just a quick response.. so don't all the math gurus yell at me about things like the volume of a vessel increase as the square of pressure increases.. he'' get the point !! lol!!!!

[kev2809]

hmm, so if my pressure switch is a 145psi cut off...that doesnt mean i have 11 gallons of air to use? it doesnt matter how full the tank is, just matters how much pressure is in it?

if thats true, do i have to get a different pressure switch?

[fleetsidelarry]

Originally Posted by kev2809

hmm, so if my pressure switch is a 145psi cut off...that doesnt mean i have 11 gallons of air to use? it doesnt matter how full the tank is, just matters how much pressure is in it?

if thats true, do i have to get a different pressure switch?

you don't need a new switch. the pressure and the volume are interelated. open to the atmosphere, which is 14.7 psi, the tank holds roughly 11 gallons if Shane's math is correct. if your pressure gauge reads zero when the tank is open then pumped to 14.7 psig (twice atmospheric) there will be twice as much air in the tank (22 gallons) and pumped to 145 psig there will be almost 10 times as much air, 110 gallons. bigger tank at same pressure just gives more reserve.

[Shane]

Originally Posted by skip99

don't forget that air is compressed. so, 11 "gallons" usually measured in cubic feet, varies on the pressure it is kept at. in other words.. you can use a tank 1/2 the size at double the pressure..

the amount of air contained in the tank varies with the pressure..

it's just a quick response.. so don't all the math gurus yell at me about things like the volume of a vessel increase as the square of pressure increases.. he'' get the point !! lol!!!!

good luck finding a 5 gallon tank rated for over 300 psi ...

[kev2809]

to bring this thing back from the dead..lol

i got a 5 gallon tank now, thinking of pulling it out and giving it to a friend of mine...and put this one in. i have a 145 psi switch, but might get a square D switch since im going to run my york with it too. will this tank be impractical with a york compressor and a back up airlift 400 compressor?

im just cleaning out my garage and still thinking of running this or not. im not happy with how many lift cycles i get with a 5 gallon....