Oil tank questions

[Tim Streater]

We have a small (1200 lt) oil tank (no gas here). Being that small means that we often run out in winter or when the price is high for some other reason. Luckily I was able to avoid the price rise in September as well as the more recent one, because of luck when getting a refill.

So I'm looking at either adding a second tank of the same size or replacing with a 2400 lt tank. Adding a second might be easier, so I have some questions, if anyone knows.

1) Is it legal to have more than one tank?

2) I had a sense there is a limit to the amount one can store in a domestic setup with tank above ground. Is this so? 2500 lt came to mind.

3) If I can have two tanks, are there any regs about how to wire them together? I'd imagined just taking the feed from each into a Y-junction and sending that towards the boiler.

[Colin Bignell]

Guidance here:

[Tim Streater]

Useful basic outline.

[nothanks]

When we moved here there were two single-skin steel tanks, each

2000-2500 litre capacity and both were weeping. I replaced them very quickly after moving-in with a 2400 litre plastic bunded tank and am now thinking of getting an additional 1000 litre tank. The plan would be to connect them in a Y, with non-return valves, but to keep the 1000 litre tank as a reserve.

[John Rumm]

It did not seem to mention how you treat multiple tanks though...

[Colin Bignell]

Nor, so far as I can see, do the building regulations.

[Paul]

Google got me some pictures.

And the series connected scheme, with low-resistance link between tanks, makes more sense. The feed is a smaller pipe, than the pipe between tanks. That may allow the tanks to equalize a bit when being pressure-filled (so both tanks see closer to the same pressure during filling).

It might mean, a single (existing) tank might only have tappings on it suited for the role as the "second-in-line" tank, and the first tank needs to be augmented for the desired connection scheme (two large holes on top).

There is a lot of variation in the quality of modern tanks. Almost like it's amateur hour, and any skills developed over the years were lost. Like, imagine buying a stainless steel tank, and it leaks after only one year. Someone doesn't know how to weld stainless.

Every geographical area seems to have their own preference in tanking schemes (steel, stainless, fiberglass). It's hard to say if any of the choices have particular merit. Even the tanks at petrol stations, seem to leak.

You can have a tank that lasts 40+ years, or a tank that gives trouble after only 1 year. Those are your choices.

Paul

[Tim Streater]

Errm yeah, but this is all North American. No use to me.

No one buys metal tanks here now. They're all Medium Density Polyethylene (MDPE).

[Colin Bignell]

Domestic steel ones are available, but MDPE tanks do seem to dominate the market.

[Martin Brown]

On replacement or new install you may also need to have one that is bunded which effectively doubles the physical size. It depends mostly on the proximity of water courses and a few other factors.

[nothanks]

Considering the delta cost of a bunded tank, and the potential cost and disruption of cleaning-up after a tank failure, I think it would be a brave person who chose a single-skin tank. Why do you think it doubles the size?

[Colin Bignell]

It would seem likely, given that the bund has to have a volume that is

110% of the tank volume.

[Tim+]

So a tank built *around* the main tank only needs to be 10% bigger.

Tim

[John J]

You would be amazed at the number of leaky old tanks that have been replaced over the years without officialdom being involved and the leakage simply left to evaporate. I know of one site where an underground pipe corroded and the 50 gallons of lost kerosine seeped under the (unaffected) lawn to kill the tomato plants in the owners greenhouse some 30 yards away. The following spring the smell had gone and the next crop grew well. Modern living is full of bullshit rules.

[Tim Streater]

It'll double the volume but not the linear dimension, as any skoolboy kno.

[Robin]

I wonder if there might be a bit terminological cross-threading here in that a double-skinned tank /is/ stronger than a single skinned one and so less prone to leaks but /isn't/ a bund. As is noted in the guidance previously mentioned at

[Tim Streater]

MDPE tanks offered here are described as "bunded" - the emphasis is more on the bunding aspect than that they're double-skinned.

[The Natural Philosopher]

I cannot see how safety is affected by having multiple tanks, provided they meet building regs individually.

[The Natural Philosopher]

LOL. He's got you there....

[The Natural Philosopher]

My rebuild 20 years ago wasn't quite that bad, but we did lose a gallon or two of kerosene that ran through a hedge and poisoned a square meter of grass. A couple of years later it had all evaporated.

We cut the metal tank up with angle grinders and put it in the skip