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Discussion Starter #1
I need a web site to figure the capacity of a cylinder in order to build a gas tank for a project i'm working on...TIA :)
 

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Red Blooded American
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Here's your formula:

The area of a circle is PI (3.1416) X Radius-squared
Square the radius in inches. The radius is 1/2 of the tank's diameter or width. Multiply it by itself.
Now multiply that number by PI (3.1416) to determine the area in square inches.
Now, multiply this area of the circle by the length (in inches) of the tank
1 cubic foot = 1728 cubic inches so divide your total square inches by 1728 to determine your total square feet
1 cubic foot = 7.48051948 US gallons so multiply your total cubic feet by 7.48051948 to get the capacity of your tank in gallons.

Cylinderr.gif

If the tank has rounded ends, it gets much more complicated.

Personally, I fill the tank with liquid than pour it back into a gas can with measuring marks. :D
 

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LAID IN MEXICO
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round ends

why not just take the diameter and multiply by 3.14 and make the round flat. then divide that number by 4 and make it square. that will make it easier to figure out. or just call a nerd like i do and have them figure it out:D
 

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Here is a real easy way

radius (Inches) x radius (inches) x pi (3.14285) x Depth/height (inches)
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231

or



r x r x Pi x d / 231= gallons
 

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why not just take the diameter and multiply by 3.14 and make the round flat. then divide that number by 4 and make it square. that will make it easier to figure out. or just call a nerd like i do and have them figure it out:D


8' dia x 8' h
48" x 48" x 3.14285 x 96" / 231 = 3009.2992 gals


96" x 3.14 / 4 75.36"......75.36 x 75.36 x 96 / 231 = 2360.1577 gals or
22% short, just sayin

Daniel
Mash on it
 

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1 so ft = 7 gallons?

I'm trying to visualize a 12"X12"X12" (1 cubic ft) container holding 7 gallons??? When that container is made round, how can it hold 7 gallons??..... I see the math, but I also see what a 5 1/2 gallon jug looks like??? Looks much larger than a cubic ft, yet holds less....?? I could see 3/4 gallon, like .748, but, really 7 gallons???......I guess I'll have to build a sq foot and prove it to myself....
Ray
 

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I'm trying to visualize a 12"X12"X12" (1 cubic ft) container holding 7 gallons??? When that container is made round, how can it hold 7 gallons??..... I see the math, but I also see what a 5 1/2 gallon jug looks like??? Looks much larger than a cubic ft, yet holds less....?? I could see 3/4 gallon, like .748, but, really 7 gallons???......
Ray
12 x 12 x 12 = 1728 / 231 = 7.48 gals


Jerry can appx 6 x 12.5 x 16 = 1200 / 231 = 5.19 gals

8" dia x 1" = 0.2176 gals per inch, so a 8 x 32 is appx 7 gals
12" dia. x 1" = 0.4897 gals per inch, so a 12 x 14.25" long tank = 7 gals ( fuel, plan on 90%, or 6.3 gals)

Daniel
mash on it
 

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Not disputing the math

12 x 12 x 12 = 1728 / 231 = 7.48 gals


Jerry can appx 6 x 12.5 x 16 = 1200 / 231 = 5.19 gals

8" dia x 1" = 0.2176 gals per inch, so a 8 x 32 is appx 7 gals
12" dia. x 1" = 0.4897 gals per inch, so a 12 x 14.25" long tank = 7 gals ( fuel, plan on 90%, or 6.3 gals)

Daniel
mash on it
Oh I see it, I'm not disputing the math, just looking at this 5 1/2 gal jug and trying to figure where it is losing volume... The old "safety" cans with the spring loaded handle/cap, they were about 12-14" in diameter, and at least 14" tall, maybe 18" even, and they just held 5 gal.... I see the math, and math doesn't lie, no dispute there. It's just the practical application, the visual, that is misleading...Kinda like pouring measured amounts of water into a pan to figure how much will fit under the tray....
Ray
 
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