Shut Off Valve Is Leaking on Oil Tank

The shut off valve at the bottom of my oil tank is leaking. Seems like a straight forward fix to replace it but I still have 1/8 tank of oil left. This is my backup for the dual fuel stoker. My question is will it do the oil gun any harm to run the tank dry? I don't want to get into having the oil pumped out or trying to collect it as it pours out uncontrollably onto the floor with a coal fire raging mere feet away. As always, thanks for any input.

Can you snug up the packing? Some valve have a hex nut under the handle to tighten the packing. Can you tilt your tank (floor jack, etc..) at all to get the oil to one end or the other without having to drain it?

I have replaced valves on tanks that were full by using a shop vac taped and sealed at the tank fill. Have everything ready to install, and run cord from vac to tank so that you can control the vacuum (it will suck the sides of oil tank in)...............good luck

If it's leaking at the packing nut, like WNY said, try to tighten the hex nut . The shop vac sounds a little

CrabRide wrote:I have replaced valves on tanks that were full by using a shop vac taped and sealed at the tank fill. Have everything ready to install, and run cord from vac to tank so that you can control the vacuum (it will suck the sides of oil tank in)...............good luck

Please explain. What are you trying to do? Use the shop vac to reduce the pressure above the full tank so that the oil can't run out when you remove the valve? I'd be surprised you could pull enough with a shop vac to do this. How can it suck the tank in when it's full? Oil would have to come out first.

Yanche wrote: I'd be surprised you could pull enough with a shop vac to do this. How can it suck the tank in when it's full? Oil would have to come out first.

A shop vac has the potential to easily crush a tank not designed for more than atmospheric pressure. We learned this the hard way while the corn burners experimented with moving material short and long distances. To avoid catastrophe - we learned to add air -- tape a valve into the line and slowly close it to regulate just enough vacuum to do the job. but not so mush to crush the tanks.

This Idea has merit - It should make the valve suck air and bubble back into the tank liquid - long enough to switch out the valve and not loose any fuel -- it may take a steady second caretaker on the bleed valve to keep things from going wrong.

AA130FIREMAN wrote:The shop vac sounds a little

I agree. I've done a similar trick when replacing valves or elements on a water tank, but you won't catch me trying it on an oil tank. Just this summer the valve I replaced in an electric hot water tank is a good demonstration why: I shut off the power and sealed all the incoming pipes. The idea is remove the old valve and the water will not stream out, it just goes "glug, glug" and within 2 or 3 glugs the new valve is started in. I've done this several times in my life, but usually for replacing the elements, not the valve. Anyway, getting to the exciting part of the story.... The old valve is tight, but I have a solid hold with a proper wrench, when, **snap!** The old valve shears off leaving the broken stub and threads in the tank, the broken valve on the floor and only 45 minutes of glug glug glug left to go. I'm real glad it was water & not oil!

The way some would weld a leaking gas tank years ago at the stock car races was to fill the gas tank completely full of gas,then arc weld it. It's not the gas in a liquid state that burns, but the vapors on top of it. If you vacuum out a tank,you are pulling out the vapors in a device that could cause ignition, that is worse than if you would be sucking the oil out of the tank with the shop vac. I am not saying it would not work, BUT could I shure would have the vac outside far away from anything on a cold -60 deg. day.

hey freddy you made me laugh on that on

my story is.. I have 4 fuel tanks 2 inside
2 outside... with a line running in I keep plugged
incase I need it... well ten years ago we had a bad wind
shear and took part of my chimney... so I went up to get the
rest of the loose pieces down and slip... down goes a partial block
hit the side of the oil tank and shears off the fire valve under the tank
almost right to the metal of the tank....mind this is a full tank
i jump down ..stick my finger in the hole and yell for help....
3 tenants home no one hears me.... finally I scoot over to a old
rag laying behind the tank and use that to shove up the hole to stop the
leak. until I can get my spare fire valve.... of course I have to spin out the
rest of the old threads.... what a mess... but you would not believe what come out of the
bottom of a outside oil tank.... what a stinking messy... mess.... funny now though

I have done the trick with the vac on a full tank and not one drop will come out. Put the vac on the vent pipe and loosen the fill cap. Have your new valve ready to install and pray that the power does'nt go out.

Lesson learned never overlook the obvious/easiest first. Packing nut was loose, got about a turn and a half on it. Seems to have fixed it. Thanks for all the advice.

I'd be surprised you could pull enough with a shop vac to do this. How can it suck the tank in when it's full? Oil would have to come out first.

Coming in late here but... my estimates are that a consumer grade shop-vac pulls about 60 inches of water, which is about 2 psi; a 275 gal oval tank is about 44 by 60 inches; so that's about 5,000 pounds total pushing in on each side of the tank. I wouldn't bet too much on my accuracy, but I'm pretty sure there would be a large pressure in general.
My dad had a 1964 Ford Galaxie, and it had a recall because the 1/8 inch or so vent hole in the gas cap was too small, and with a long full throttle run the fuel pump could collapse the gas tank. We didn't get near that. But I drilled a second hole anyway, which was the fix for the recall.
Yeah, if the tank has oil in it, it would want to go somewhere when the vac was collapsing the tank. Nowhere good.

Gzuckier wrote: ↑

Sun. Feb. 25, 2024 3:46 pm

Coming in late here but... my estimates are that a consumer grade shop-vac pulls about 60 inches of water, which is about 2 psi; a 275 gal oval tank is about 44 by 60 inches; so that's about 5,000 pounds total pushing in on each side of the tank. I wouldn't bet too much on my accuracy, but I'm pretty sure there would be a large pressure in general.
My dad had a 1964 Ford Galaxie, and it had a recall because the 1/8 inch or so vent hole in the gas cap was too small, and with a long full throttle run the fuel pump could collapse the gas tank. We didn't get near that. But I drilled a second hole anyway, which was the fix for the recall.
Yeah, if the tank has oil in it, it would want to go somewhere when the vac was collapsing the tank. Nowhere good.

14 year old thread.

That's ok.. I just learned something.