Underground Oil Tank - without a whisle stop

Jim321

I recently purchased a house. The oil company told me that the tank was put in a few years ago. The first guy added oil to the tank for the first few times. We determined that the tank was full around 38 inches while using his manual dip stick. The next guy overfilled the tank and I believe got oil in the vent pipe. Now when they went to fill it, it came out the vent pipe when it was as 24 inches. I removed the vent cap and blew the oil back into the tank with a shop vac reverse vacuum. They are now telling me that they will not fill without a whistle stop. I believe I have a straight fill pipe and my vent pipe comes vertical to a 90 degree horizontal and back to a 90 degree vertical with a vent cap on top.

What are my easiest and best options to resolve the issue?

Can I add any type of whistle stop to my vent pipe? Do I have to dig up the tank and remove the 90 degree horizontal out of my vent and add a special whistle stop to measure the vertical distance for the extension? Do I need to dig up and find another tank access to add an extension whistle stop?

Intplm.

You can add a vent alarm to your current tanks vent. You will need to dig down to the tapping and install it there at the top of your tank for the vent alarm/whistle to read the flow height properly. The vent will need to be heard by the delivery person from above ground of course, so the vent opening/cap should be near the fill so the person filling the oil can hear the vent stop, indicating a full tank.

EdTheHeaterMan

When I delivered fuel oil, every truck was equipped with a portable underground tank whistle-stop

The driver would place the portable fill device in the fill pipe of the tank then adjust the whistle to contact the top of the tank. when the whistle stopped there was about 4" of space left at the top of the tank.

Look for another fuel oil supplier that already has these on their delivery trucks.

Jim321

intplm, Thanks for your feedback. Please provide more detail. A standard scully ventalarm whistle stop would be underground. Is there a different style I should be using?

Jim321

Ed, Thanks for your support. I believe one of my oil delevery guys tried to use that and it didn't work. I believe it was because there was oil in my vent pipe from the overfill. That is why I used the vacuum to blow into the vent pipe. Does this sound correct? Would it blow oil out my vent when not being close to full? I think the portable whistle should work now.

EBEBRATT-Ed

@EdTheHeaterMan is correct. All oil trucks were equipped with the portable whistle back when I delivered oil as well.

But you have a couple of issues:

1. The vent pipe is supposed to be pitched so that it is lower on the tank end and higher at the capped end. This allows any overfilled oil to drain back to the tank. The vent pipe is not supposed to hold oil.

2. They should have put a whistle on the tank especially if the tank is not that old. The portable whistle was used on underground tanks back when whistles were not required. And I am talking old.

The only way to solve the problem is to dig up the vent pipe and relace/repitch and install a whistle at the tank.

What you could do (depending on the tank location, under grass?, under pavement?) is to dig up the vent pipe at the tank cut the old vent pipe off and install a new pipe with a whistle coming straight up out of the tank. Make the vent pipe the same size as the fill pipe and make the vent cap higher than the fill pipe and paint the pipe before backfilling.

Then depending on location leave it that way or repipe the original vent in the summer. The top of the tank is usually about 2' below grade. You can figure this out by using a tape measure with a hook on the end and hooking the bottom of the fill pipe.

A standard Scully vent alarm with threaded connections. The compression style is not allowed underground.

Jim321

EBEB, Thanks! What is the name of the underground whistle stop that I will need if I add it to the base of a vertical vent pipe underground? Is there any other reason why it would push oil out my vent pipe when the tank was half full?

EdTheHeaterMan

Here is your part. King Fill Alarm. there are other brands like Scully and OEM (stands for Oil Equipment Manufacturers)

Intplm.

https://forum.heatinghelp.com/discussion/comment/1832918#Comment_1832918

@Jim321 This is a picture of a type of vent alarm. You will need to do what @EBEBRATT-Ed suggests above.

You will also need to find the top of the tank to get the correct size vent alarm. It will probably be the same diameter as the vent pipe. Hopefully two inch. If its older it could be inch and a quarter or inch and a half.

Jim321

Thanks for everyones help. My vent pipe is 1 1/4". I will start chipping away at the frozen ground on Saturday and see what my connection looks like. Do they put welds on the pipe connections to the tank?

EBEBRATT-Ed

@Jim321

No the pipe is threaded. Keep in mind that the tank may have a threaded bushing in it. On some tanks they made all the tapping's 2".

In the old days it was common to use a 2" fill with a 1 1/4" vent. Current regulations are the fill and vent are supposed to be the same size. But do what you have to do.

As far as oil in the vent when the tank is half full it is common for the oil to foam so maybe some of that worked its way into the vent but it shouldn't have with the tank 1/2 full.

Most Tanks now are 48" in diameter for residential weather it is 500 or 1000 gallon. The 500 is about 5' long and the 1000 is 10' long roughly.

I guess they do make some smaller tanks in 38" dia.

Jim321

Thanks EBE,

My current vent is 1 1/4". I am thinking that the tank opening will be 2". I bought a Scully 2" x 1 1/4" whistle stop. I hope to get thru the frozen ground soon to see what I have. I am pretty sure that I have a 500 gal tank. Have a great day!

Intplm.

https://forum.heatinghelp.com/discussion/comment/1834429#Comment_1834429

If you have trouble breaking ground, look for a company that will deliver oil, maybe a different one that will stick the tank for a measurement and deliver the old way without a vent alarm. If not, appeal to your current supplier (s) and let them know you are in the process of getting the alarm installed. They should come by. They usually will. They want to sell oil and they don't want to leave you without heat. They don't necessarily have to fill the tank to the top.

EdTheHeaterMan

When you put the pipes back in for the vent, you may want to use a swing joint in order to get the piping to pitch the proper way towards the tank to drain the vent back to the tank, if it ever gets over filled again.  Your tank return tapping may be in a position where it will cause the vent to have the wrong pitch if you don't use a swing joint. 

Of course this illustration may be exaggerated, but you get the point. The vent pipe on the left will fill with oil that will not drain back to the tank. The swing joint will allow the proper pitch to drain the oil back to the tank. 

A swing joint is made up with two elbows like the picture on the right. 

 The picture on the left has only one elbow and will not allow for adjusting the pitch as needed