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Above-ground Oil Tank Leak at Fill-Pipe?

Alex_19 Member Posts: 19
Hey Guys,

We recently had an oil delivery, and have smelled a stronger than usual fuel oil smell for about three days. I went to inspect the above-ground oil tank and the entire heating plant. Everything seems normal with the boiler, oil line, and chimney. I have isolated the odor to the top of the tank, and can feel oil sheen on and around this immediate area. I can see some streaking on the side of the tank, in the yellowed area seen on the picture. Looking underneath the tank, I do not see any leakage. The tank is approximately forty years old.

The last few times the tank was filled, this did not happen. I am wondering whether this was caused by an overzealous oil courier or an aged tank.

Can you please advise me what repairs can be effectuated to prevent this from happening?

To alleviate the odor and oil residue, I was contemplating using a degreaser on this area of the tank similar to one the oil company technician used on the oil line by the burner when he serviced the burner a few months ago. Would this be advisable?

Thank you for your guidance with this issue.

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  • billtwocase
    billtwocase Member Posts: 2,385
    edited March 2012
    looks like

    you need all pipes and fittings removed, resealed, and tightened. Is this in Mass? Although you would see this on older tanks, and this looks to be a late 50's, early 60 tank,  the fill should not be larger in diameter than the vent pipe. Also it may be getting slightly over filled. The vent alarm has a bushing, and even worse, it was common practice to cut the whistles to get more oil in the tank.  I would have your company do the needed repairs. I wouldn't advise doing too much rubbing or wiping of this old tank. You can pat it dry, and have them use an odor neutralizing powder on the affected areas, and have the bottom of the tank checked as well, as that is where it collects. Also ask you oil supplier if the whistle is working properly. If it isn't, and they filled it anyway, they are not too bright or responsible. Filling that tank is guess work if no whistle or adequate air release while filling. They can and will open up, and it's not pretty
  • icesailor
    icesailor Member Posts: 7,265
    Oil Smell:

    No big deal. Unless the tank is overfilled out of the tank and into the vent and fill.

    IMO, it;s caused by a high volume fill rate and foaming of the oil. Before the liquid level gets to the bottom of the whistle (where the leak is), the foam is into the whistle assembly. After the fuel is shut off, the product leaks out through the thread. One drop of product dropped in water will make it appear that the Exxon Valdez dumped its load. The same with the smell. The easiest thing to do is wipe the oil off the tank top after a delivery. You could leave a clean rag around the whistle and after a fill, if it has leaked, replace it.


    You can take the whole thing apart and repair it. This thought is giving me a headache. But, that said, unscrew the vent piping and put new pipe dope on the threads. Make sure you have two, 2' pipe wrenches. You will need to remove the concrete/mortar where the pipes go through the wall unless wood. You should NEVER use Teflon Tape on the threads. They stop the leaks. That said, I have used Teflon Tape for over 40 years on EVERYTHING I thread together. Especially oil tanks. The threads usually suck and they always seem to want to leak where yours do, on the top. I use Teflon Tape and Rectumseal #5 on the threads, male and female. #5 is totally impervious to fuel oil. If you get it on your clothes, it will never come off. Every leak I ever see on an oil tank like yours has no Teflon tape on the threads. Regardless of what type of thread sealant used. And I've used most of them.

    If you call a professional to fix it, he will get a headache and not want to deal with the factoid of unintended consequences because he/she won't want to use Teflon tape and it may leak worse than now.

    After the above, put a rag around it is leaking slightly. I've seen them run down the side of the tank.

    You can also ask the fuel company to slow down the delivery rate but that may fall on deaf ears.
  • lchmb
    lchmb Member Posts: 2,997
    you could

    also look into the option of having the tank replaced. 40 years old has paid for itself and new tank and piping is not a bad option...Little more expensive now but cheaper than a leak...IMHO...
This discussion has been closed.