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Working out gas bottle capacity?
coozer - 29/5/10 at 07:03 PM

Googled it but very confused...

All I want to know is how many litres of petrol would I get in a 19kg gas bottle?

And, how many litres of air in a 47kg bottle for use as a compressor receiver?

Any knowledgeable dudes here can tell me??

LG,
Steve


rusty nuts - 29/5/10 at 07:15 PM

Doesn't 1 Lt of water weigh 1 kg?


coozer - 29/5/10 at 07:20 PM

Maybe but its original gas weight is based on many thousands f litres compressed. Not the same as an uncompressed liquid...


MikeRJ - 29/5/10 at 07:25 PM

Propane has a density of 583.07 kg/m^3

19kg gives 19/583.07 = 0.03537 m^3 or 35.37 litres.

However, they aren't filled to the top, so the usable capacity for liquids may be a bit more.

for the larger bottle:
47/583.07 gives 80 litres.


asn163 - 29/5/10 at 07:28 PM

Hi, it depends upon what gas is involved.

I assume you are talking either propane or butane cylinders, low pressure liquefied gas cylinders?

The charge weight (gas weight) is the water capacity multiplied by the filling ratio. For butane, the standard filling ratio is 0.52 (with min test pressure of 10 bar) so your 19kg cyl. would be 36.5 litres and your 47kg, 90.3 litres.

For propane, the filling ratio is 0.43 (min. test pressure 23 bar) so the water caps. would be 90.3 litres or 109 litres.


In terms of the number of litres of air, this would depend on the water capacity and charging pressure.

As a rough guide, the "free air capacity" in litres is the charging pressure in bar multiplied by the water capacity in litres. This would give an approximate value and is OK up to 200/250 bar. For a more accurate value you need to include a compressibilty factor.


HTH.

Simon

[Edited on 29/5/10 by asn163]


hillbillyracer - 29/5/10 at 07:28 PM

How accurate do you need to be?
It'd be simple enough to measure height & diameter, have an educated guess at the wall thickness to subtract off & just calculate the volume that way?


RichardK - 29/5/10 at 09:25 PM

Cor...theres some good sums here I'd just lob the top off, get the hose out and give the kids a jug and quid when they've finished emptying and counting

Cheers

Rich