House we moved into last month has twin 275 gallon heating oil tanks in basement. They look old but no visual signs of seepage or any sort of compromise.

Tank #1 is connected to Tank #2 with a 3 inch pipe across the top.

Tank #1 has a 2 inch fill pipe. Tank #2 has NO fill pipe but has the vent pipe which looks smaller, maybe 1.5 inch diameter?

I am assuming that the previous owner would have them do a full fill up and basically Tank #1 would fill all the way up then the crossover pipe would allow Tank #2 to fill up as well.

I've got about 1/2 tank full of oil in each tank right now and they appear to be emptying at the same rate, there is a connection from each tank at the bottom front that goes to a "T" and the oil line to furnace. Both tanks have shut off valves before the "T"

My question is, am I asking for trouble doing a fill up where Tank #1 is getting pressure from being fully filled before the crossover pipe starts taking the oil over to Tank #2? I don't want to have a situation where a tank ruptures on me and I find fuel oil going down the floor drain about 12 feet away.

Should I just get Tank #1 filled from now on and basically ignore the dual tank setup? I need to get through this winter and most likely next before I can afford to convert to NG at this point. I estimate I will need to get more oil by early February.

I don't think you'll have any issue at all. You'll likely want to run tank 2 almost empty, then close the valve at the bottom off.

There's no real pressure in those tanks outside of the weight of the contents.

How high is the tank? I don’t know the exact weight of heating oil, but I’ll bet it is less than water at 8#/gallon. The head of water is .43197 pounds per foot. With a tank of water 12 feet high full of water, the pressure at the bottom of the tank would be less than 6psi. Given that your tank is likely less than 12’ tall and the heating oil is likely lighter than water, the pressure on the tanks is completely insignificant. I would not worry at all about the pressure on the tanks.

ETA: The tanks will also both be equalizing from the bottom unless you close the valves before filling. The big crossover pipe is there so that if the first tank is filled faster than it can flow through the bottom plumbing you still fill the second tank.

My concern is the oil delivery guy filling up the first tank and having to pressurize it so much that the top connecting pipe starts to pick up the oil into the second tank and a rupture occurring at that point.

Tanks are 44 inches tall and on legs maybe 12 inches high.

I had the same setup in my previous home with two 275 gal oil tanks in the basement with a crossover in the middle.

I had no issues. Just make sure and have the filter between them changed for good measure. There are youtube videos I believe.

There is no pressure with oil. Just gravity. Similar to putting gas in your car. He hooks up, pulls the valve, and oil flows downhill into your tanks. The only time the oil is under pressure is after the pump on your boiler/furnace.

The vent will release the air displaced by the oil filling the tank.

OK, thanks guys!

Just curious, is natural gas cheaper than rice coal? Will it remain affordable? I know Pa has been fracked to beat hell and there is loads of gas but, my brothers Key Stoker rice coal furnace costs him less than half of fuel oil, per winter and it makes a constant heat, never shutting down. He does have to deal with ash. The Key Stoker is made in Pennsylvania.

quote:

Originally posted by PASig:
My concern is the oil delivery guy filling up the first tank and having to pressurize it so much that the top connecting pipe starts to pick up the oil into the second tank and a rupture occurring at that point.

Tanks are 44 inches tall and on legs maybe 12 inches high.

The leg height is irrelevant. Call it 4’ and the head if the tanks were full of water would be less than 2 psi. The head of heating oil would be less still. No worries at all.

quote:

Originally posted by David Lee:
Just curious, is natural gas cheaper than rice coal? Will it remain affordable? I know Pa has been fracked to beat hell and there is loads of gas but, my brothers Key Stoker rice coal furnace costs him less than half of fuel oil, per winter and it makes a constant heat, never shutting down. He does have to deal with ash. The Key Stoker is made in Pennsylvania.

NG is very affordable right now in PA, it's lower now than it's been in years and I looked at my NG costs for the old house we moved out of and it was around $700 for year, and that included hot water. I will be spending about 2-3 times that for oil until I can get in a position where I can have a gas line run and furnace replaced.

My BIL had a rice coal furnace and it seemed like he was always screwing with it to get it to run properly. He's gone back to heating with oil this year I believe.

OK. Likely the gas is a cleaner source. The Key Stoker my brother has only requires ash pan change, bin holds 200 pounds and occasional flu cleaning. His is problem free and he still has his fuel oil for back up. Keep warm.

quote:

Originally posted by PASig:

I've got about 1/2 tank full of oil in each tank right now and they appear to be emptying at the same rate, there is a connection from each tank at the bottom front that goes to a "T" and the oil line to furnace. Both tanks have shut off valves before the "T"

Here is what you are missing I think, as long as both drain valves are open the tanks are tee'd together and will fill and drain in unison... they will automatically flow between them and level out, no pressure required.

quote:

Originally posted by cparktd:

quote:

Originally posted by PASig:

I've got about 1/2 tank full of oil in each tank right now and they appear to be emptying at the same rate, there is a connection from each tank at the bottom front that goes to a "T" and the oil line to furnace. Both tanks have shut off valves before the "T"

Here is what you are missing I think, as long as both drain valves are open the tanks are tee'd together and will fill and drain in unison... they will automatically flow between them and level out, no pressure required.

This, they will gravity feed and the 2nd tank will vent and they'll level out. You need them both open in this arrangement so that the tank 1 will vent when you draw from it. Just fill them both up. THERE IS NOT ISSUE WITH OVERPRESSURIZING THE TANK BY FILLING IT WITH THE VALVES OPEN, less pressure actually.

I worked on some yachts where we'd take diesel at 250 gallons per minute. They filled the same way.......Having the crossover open at the bottom allows the 2nd tank to start gravity filling as they will up the 1st tank. The top pipe is so that tank 1 vents from the 2nd tank which has the vent basically, and is an overflow so once the 1st tank gets to near full and the 2nd one might only be 60% from gravity filling it, it helps it equalize faster.....

You have the ability to fill both full, shut the bottom valve and you'll know exactly when you get to 1/2 capacity and can then take 250 gallons etc. Or just leave the bottom valve open and use both tanks at the same time.

This message has been edited. Last edited by: jimmy123x,