Heating oil tank capacity

Pompey Magnus

I bought a second hand home heating oil tank recently, it was advertised as having 1000L capacity, the guy who sold it did say he had been told by his supplier that it might hold a little over that. I got a delivery of 1000L yesterday and there is probably room for close to another 200L now, but after the delivery I noticed for the first time that the capacity marked on the tank shows 950L.

Just how accurate is the manufacturer's capacity estimate, could it really be out so much that 1000L could fit into a estimated 950L tank with plenty of room to spare or did I just get a delivery of maybe 750L for the price of 1000L? If the manufacturer's estimate isn't accurate is there any way for future reference to get an accurate measurement of the capacity of the tank?

emeldc

Are you sure the '950L' wasn't just a marker for 950 Litres.

Pompey Magnus

emeldc wrote: »

Are you sure the '950L' wasn't just a marker for 950 Litres.

I'm sure, it said "Norm. Capacity 950L"...it was very faded though so I missed it until yesterday.

I know the tank isn't going to be exactly 950L but surely it couldn't be so off the estimated capacity as to be actually closer to 1200L?

ytpe2r5bxkn0c1

I have never come across a 950L tank. It is probably 1000. As suggested the 950 may be a marker. Where on the tank is it?

Pompey Magnus

Angelo Embarrassed Therapist wrote: »

I have never come across a 950L tank. It is probably 1000. As suggested the 950 may be a marker. Where on the tank is it?

I just had another look, it is roughly 2/3 of the way up the tank and says "Norm. Capacity 950L".

P. Breathnach

How are your basic maths skills? You could measure the tank and do some arithmetic.

Teagwee

Here you go - get calculating
http://www.calculatorsoup.com/calculators/construction/tank.php

Pompey Magnus

Teagwee wrote: »

Here you go - get calculating
http://www.calculatorsoup.com/calculators/construction/tank.php

Unfortunately it is a pretty awkward shape so calculating volume would be tough...

Teagwee

You'll get a rough estimate though and may be able to adjust down slightly for the indentations. It will indicate the absolute maximum capacity at least. Interested to see what you come up with

L1011

Tank capacity is less than what they'll hold to the brim to cope with fuel expanding in the heat - and its very cold at the moment. You'll lose a few percent volume from that straight away. Also the tank is narrower at the top so what looks like a lot of space isn't.

The dispensing equipment should correct to give equivalent delivery at a specific temperature meaning you don't either benefit or lose out due to temperature variations.

There is also a chance you were under-delivered, this happens both by accident and malice.

Pompey Magnus

Teagwee wrote: »

You'll get a rough estimate though and may be able to adjust down slightly for the indentations. It will indicate the absolute maximum capacity at least. Interested to see what you come up with

I did some very rough measurements and calculations, I got the volume of a tank made of the maximum width with no indentations and then the volume of a tank made just to the size of indentions and averaged the result. I then added on the volume of an ellipsoid that the two curved ends of the tank would roughly create. This gave me 1065L.

The delivery left the top 18cm of the tank empty (it filled 102cm out of 120cm).

Teagwee

Pompey Magnus wrote: »

I did some very rough measurements and calculations, I got the volume of a tank made of the maximum width with no indentations and then the volume of a tank made just to the size of indentions and averaged the result. I then added on the volume of an ellipsoid that the two curved ends of the tank would roughly create. This gave me 1065L.

The delivery left the top 18cm of the tank empty (it filled 102cm out of 120cm).

Sounds about right to me, though I'm no expert. My gut feeling is that the operational capacity is 1000 litres, allowing appropriate headspace for use. If you're around the next time the tank is filled, the delivery lorry has an accurate gauge that prints out a receipt - you can watch the whole process if you're in any doubt.