Does anyone know how many litres there are in a normal propane gas bottle? I think they are sold by weight which I believe is 13 kilos.

If it is Propane Gas the sizes are 3.9kg, 6kg, 13kg, 19kg or the huge 47kg. If it's Butane the sizes are 4.5kg, 7kg and 15kg.

There are 91.8 Litres in a 47kg cylinder so you can then calc backwards

Jammy thank you. Brains the size of planets on British Expats. I have said it before and I say it again.

So if I multiply by two then i should not be far wrong.

Thanks again

We use 13kg propane - can't do the math that Jammy can (respect) - have always used it, it's the one that can fit the mobile heaters (tho don't have one any more). Our hob uses it via link to adjacent atelier. Lasts a long time is all I know. We have acquired a couple of extra cylinders over the years (you may even find a spare on vide grenier), so just keep an eye on weight (that is my rule of thumb) and buy new to be in waiting. This size also fits well with gas fired BBQs (okay so I'm not a proper Cobber not using charcoal), but having the extra cylinder means, if you do fluff it and not got a spare in you can resort to the BBQ.
Question: knowing the number of litres of gas, how does that relate to how much I use when I'm doing a stir-fry?

No you can't. What's the pressure in the tank?

The MW of propane is 44 g/mole. So 1 kg of propane is 22.7 moles, or 47 kg is 1006.9 moles.

It's late at night here in the EST zone but I reckon that works out to a pressure of 27 atmospheres, (~400 psi). This is not unreasonable but you certainly can't "calc backwards" without this information.

Novocastrian
My French and German is okay. My Spanish not bad and my Italian is a work in progress, thanks to a Latin education. One European language I do not speak is Greek.
Unfortunately, matters scientific are all Greek to me!
Any chance you could translate that, preferably into English, as my reference to brain size should have excluded myself

Novo,
Are you suggesting that the moles in my garden are high on propane?
I wondered where that smell was coming from........

Mole is a very popular Spanish dish

Completely baffled by the calculations. All I know is we have a magnetic gizmo that sticks on the side of the cylinder and lets you know when it is about to run out. We always have a spare, and we always chalk the date of first use on the cylinder.

I have a big range stove with 4 rings and a professional-type heated plate which I use a lot but we only get through about 3 cylinders a year.

Now that's what I call good info. I never think (doh!) of putting a date chalked on the bottle and I've never heard of your 'gizmo' - can you share more info, does it cost a lot?

Hi

I got the gizmo from an on-line camping store in the UK - it was really cheap. I actually bought it as a stocking filler a couple of Christmases ago.

I'll try and find the site for you.

Hi again

Here you go:

http://www.amazon.co.uk/Caravan-Moto.../dp/B001I28QO6

OK. Assuming the 47 kg is the weight of the propane (i.e. excluding the weight of the cylinder itself), that's 1006 moles x 22.4 liter/mole at 1 atmosphere (the pressure at which its used) and standard temperature. 22,534 litres in all.

That's wicked. Cheers grannybunz, will get one sorted.