Twin tanks

BonnieSue

I have 2 275 gallon tanks twinned together with only one gauge. If the gauge reads 1/2 full, does that mean each tank is 1/2 full or does it mean I have 1/2 left total in one tank?

Pumpguy

Depends on size and height of tanks and how they are piped.

If both tanks are same size and height, and both are vented to atmosphere, level will be same for both tanks.

If one tank is taller than the other, and both are vented to atmosphere, or connected at their tops too, the shorter tank could be completely filled while the taller tank would have room for more liquid.

STEVEusaPA

Yes, pictures please.

Mad Dog_2

Hey Dennis..are u related to former NY governor George Pataki? That's not a common name? Mad Dog

EBEBRATT-Ed

The tanks should have the same level. It is possible to have a blockage in the lower connecting pipe that connects both tanks which could make the level unequal.

You could have a second gauge installed on the tank that doesn't have one, but it is probably unnecessary.

BonnieSue

tanks are the same height

Mad Dog_2

Please take pics of piping under the tanks  mad Dog

Pumpguy

@Mad Dog_2, No relation that I know of, although I do have a 2nd cousin whose first name is George.

DNA check would probably show something, I would expect.

Ethnic background is Hungarian. Name's much more common over there.

EdTheHeaterMan

Since both tanks are installed at the same level and piped with one fill pipe in tank #1 and one vent pipe in tank #2, and a cross over at the top to facilitate oil flow from the full first tank to the second tank then at first glance the tanks should eventually even out over a day or so. This is based on the fact that the bottom tank valves are open for both tanks, and will be connected together with a Tee fitting to the oil burner. Since the bottom tank piping is most likely 3/8" copper tubing (or 1/2" iron pipe at the most) there will be some delay in the leveling of the two tanks following a fuel delivery. But eventually (a day or so) the level will be equal.

BonnieSue

Here is how they are hooked up at bottom of tanks. The one pic shows piping that goes to the furnace

STEVEusaPA

In theory they should level out, but I wouldn't count on it with that set up. Fuel would have to go backwards through the filter, through the thermal fused valve to level out. And if one filter/line clogged, you would never know it
Also, those tanks are over 40 years old, the steel piping on the bottom of the tanks is questionable.
Although not against code, I don't like the crossover fill piping where the first tank has to get completely full to fill the second one.
Separate fills and connected vents are better. Then each tank can have it's own gauge.

BonnieSue

Thanks all for your help. I think I will see about having it changed so I can get separate fills and two gauges.

EBEBRATT-Ed

@STEVEusaPA Never liked 1 fill 1 vent and the crossover. Puts too much pressure on the first tank when filling IMHO

Mad Dog_2

I don't like the look of those bottom tank connections and piping either .  I'd consider brand new tanks and piping.  Mad Dog

Mad Dog_2

Ahhhh The Magyars... a Great people.  Mad Dog