Fuel Oil Tank Capacity Chart ?

Dave___in___CT · Aug 5, 2004

Hi...

Have a buried 1,000 gallon horizontal fuel oil tank that's 48 inches in diameter.

Looking for a capacity chart so I can determine how much oil is in the tank when I measure it's depth.

Didn't find one searching the net.

Thanks...

Dave...

Steven · Aug 5, 2004

Maybe this will help volume of partial filled cylinder

zuiko · Aug 5, 2004

Your oil dealer might have a chart too. That is where I got mine back when I had an underground tank. It just has the inches with # of gallons at each level. The cylinder thing would probably work too. As far as I know these big underground tanks are pretty much cylindrical in shape (as opposed to above ground tanks which are often not).

Junkman · Aug 5, 2004

simple answer since I don't know where my chart is.... if you have a half tank, 500 gallons.... after that, you need the chart, because as you get closer to the bottom, the amount of oil diminishes because the sides taper in. I will check tonight to see if I can find my chart.

or

you can use this formula:

Here's a way you can get a close estimate of the volume.

1. Take the diameter of a tank in feet and calculate the area of the circle.
2. Take this area and multiply it by the length of the tank.
This will give you the cubic feet of the tank.
3. Multiply the cubic feet by 7.48. This will give you the gallon capacity of the tank.
4. Draw a large circle to represent the end of the tank. Draw in the 'Y' axis and divide it into an equal number of parts to represent the foot marks of the circle; e.g.; if the diameter is six feet, divide the 'Y' axis into 6 equal parts. Now divide each of the 6 part into 12 equal parts.. These will represent the inch marks. Number these marks from bottom to top
5. Now you can start calculating the segments of the circle using the following formula;

........................R^2............pi x segment angle
Area of segment= ---- x -------------------------- - sin of segment angle
.........................2...............180 degrees

6. Take the area of the segment you just calculated and multiply it by the length of the tank times 7.48. Subtract this number from the total capacity of the tank you calculated previously. This will give you the remaining gallons in the tank.

7. Draw this segment on you circle. Note where the chord of the segment cuts the ‘Y’ axis. This point will be the gallons remaining for the height registered.

Happy calculating!

MadReferee · Aug 5, 2004

Attached is a chart.

MikePA · Aug 5, 2004

If it's 48" in diameter and you insert a measuring stick into the tank and the mark the oil leaves on the stick is 12" up the stick you have roughly 250 gallons in the tank, right? If the mark is 9" up the stick, you have roughly 188 gallons.

MadReferee · Aug 5, 2004

( If it's 48" in diameter and you insert a measuring stick into the tank and the mark the oil leaves on the stick is 12" up the stick you have roughly 250 gallons in the tank, right? If the mark is 9" up the stick, you have roughly 188 gallons. )

Nope. Take a look at the chart I attached in my previous response. That chart came from my oil company who installed my 1000 gallon tank. The standard 1000 gallon underground tank is 48"x 10'8".

12" of oil in the tank gives you 196 gallons. 9" will give you 130 gallons. You will need 14"-15" of oil for 250 gallons. I have personally verified that the chart is accurate.

Junkman · Aug 5, 2004

( If it's 48" in diameter and you insert a measuring stick into the tank and the mark the oil leaves on the stick is 12" up the stick you have roughly 250 gallons in the tank, right? If the mark is 9" up the stick, you have roughly 188 gallons. )

If the tank was a square, you would be correct. The only time that your theory would be correct is at the 50% mark. The sloped sides are what make the difference. I have been looking for my chart for a couple of hours now. I am glad that one was posted, because I believe that mine is permanently misplaced. When I was in the business, we had them all over the office. Now I have none..... /forums/images/graemlins/frown.gif /forums/images/graemlins/frown.gif

Junkman · Aug 5, 2004

One other thing to remember about underground storage tanks. The pick up is usually located about 6" from the bottom of the tank, so you don't pick up water if there is any in the tank. The tank is also set at an angle so one side is higher than the other, so the measurement is an approximation only of the gallonage left. The tank should be checked at least once a year for water, and if you fill it in early summer, so there is little chance of moisture condensing from the humid air, you shouldn't have any water in your tank.

MadReferee · Aug 5, 2004

6" on a 1000 gallon tank is about 75 gallons of oil. I would be real upset if I had to leave that much in. My tank, which was installed in 1979, will have only 1.5" of oil left when it runs out (I know since I just ran it out last year).

On my tank the copper pickup tube enters from the top and is dropped into the tank so the tank does not have to be angled. I have never had a burner failure due to excessive water but I do change the filter by the burner every year.

My hot water is heated by oil so the oil is used year round. I typically fill the tank in august/september but I may hold back this year until prices settle lower or just buy 200-300 gallons at a time.