LPG Meter reading - m3 / litres

J_B

Just checking really. we have a meter on our LPG supply, one like the first one here http://www.mwatechnology.com/gas_meters/diaphragm.php

It measures m3 and when I went to school there were 1000L in a m3 but I just wanted to check that there was no spurious discrepancy because of pressure or something.

I don't buy from Flogas so don't expect the conversion to rise unexpectedly! :rotfl:

macman

Yes, 1000 litres is 1 cubic metre.
It's not pressurised.

matelodave

That sort of meter will measure gas by volume when its a gas, what gets put into a tank is usually measured in litres because it's a liquid, so 1000 litres of liquid gas will make a lot more than 1cu.m of gas.

The expansion volume is about 270:1 so you would get about 270 litres of gas from 1 litre of liquid although that would also depend on the temperature & pressure.

1kg of liquid propane = 1.96 litres = 0.54 cu.m of gas = 13.6kw/h = 49 Mj

J_B

well, many thanks for those two completely opposing opinions

:cool:

Mister_G

According to EU Regs, 3.85 litres of liquid propane is 1 cubic metre of gas at standard temp and pressure (which is 15°C and 101.3kPa). Hope that helps.

matelodave

J_B wrote: »

well, many thanks for those two completely opposing opinions

:cool:

no, they aren't.


A cubic metre is 1000 litres and always will be however only if the substances are in the same sate - ie 1cu.m of gas is 1000 litres of gas. 1 cu.m of liquid gas is 1000 litres of liquid gas.

Therefore a cu'm of liquid propane converted into gas would have a 270 times greater in volume = 270 cu.m or 270,000 litres

macman

I didn't mention propane. I simply confirmed that 1000 litres is the same volume as 1 cubic metre.
Obviously if you change the temp or pressure of a gas then it will alter the volume.

J_B

macman wrote: »

I didn't mention propane. I simply confirmed that 1000 litres is the same volume as 1 cubic metre.
Obviously if you change the temp or pressure of a gas then it will alter the volume.

yes, but I *did mention that I was metering LPG

matelodave wrote: »

Therefore a cu'm of liquid propane converted into gas would have a 270 times greater in volume = 270 cu.m or 270,000 litres

Mister_G wrote: »

According to EU Regs, 3.85 litres of liquid propane is 1 cubic metre of gas at standard temp and pressure (which is 15°C and 101.3kPa). Hope that helps.

So ..... 1 m3 is either 270,000L or 3.85L

Hmmm, not much difference! :cool: :rotfl:

Mister_G

Hi JB

I can only confirm that 3.85 litres of liquid propane (which is under high pressure) becomes 1 cubic metre of propane gas at the pressure that your meter measures.

J_B

Mister_G wrote: »

I can only confirm that 3.85 litres of liquid propane (which is under high pressure) becomes 1 cubic metre of propane gas at the pressure that your meter measures.

I suspect that you are correct

It's a difficult one to fathom.
We have a pair of cottages in N Wales which we do holiday lets in. We have an underground tank which feeds the first house then through the meter to the 2nd house.

The historical details are a little sketchy, but we have been going for four 'seasons'
When we left calor in the spring of this year, they told us that our average use was 2500L per year so over 4 years we should have used 10,000L.
The meter currently reads 1000 m3, which by your calculations is 3850L - i.e. 38% of the total use
The first house is slightly bigger than the second one and the Calor 2500 was maybe an estimate, so I will go with what you said.