C02 cylinder Tare Weight Help

[danwlx]

Hi all, I'm trying to find the tare weight of my cylinder to find out how close to empty it is, looking at the cylinder the stamps aren't that clear but it seems to say 'TW 15,20KG' and next to it 'GW 21,55KG'. Now I think this means that the empty weight is 15.2kg and full weight is 21.55kg, do you think this is right?

I''ve had the cylinder for about 6 brews and have used it to purge air from cylinders etc and I was expecting it to have made quite a dent in the c02, but I'm weighing it at 20kg which would mean plenty left.

Thanks for all help.

[Fil]

I have an empty from liquide air up the shed i keep meaning to get replaced i can weigh it to see tomorrow, shout at me in here if i forget (likely)..

[danwlx]

Hi Fil, great stuff, mine is a liquide air cylinder too so that would be ideal.

[Fil]

Thats good as it dawned on me after i posted that there are different bottles out there,
btw mine is a flat bottomed grey bottle with a purple neck guard..

however your looking at a good length of use from a single cylinder Ive dropped more co2 than i have used with a leak tight system and no cockups your looking at 18months-2years use with a few cornies on tap.

[danwlx]

That's the same cylinder I have. That's a lot longer use than I expected but good news! This is the first cylinder I've used so was unsure on the likely lifespan.

If you could weigh the cylinder it would still be really helpful as I'll be able to judge when I need a new one.

[rpt]

21.55 - 15.2 = 6.35kg

Sounds spot on to me for a pub cylinder.

[Fil]

just weighed my empty cylinder/co2 bottle

13.6kg

took longer than expected the bathroom scales need bare feet to trigger the weighing function or something, needing me to work out how to step on bare foot, to activate, wait long enough and step off for a zero measure before quickly but smoothly dropping the empty bottle onto the glass scales plate..

so a 15kg bottle is probably on the money fraid i couldnt make out the tare stamp on the bottle - need new glasses post an eye op..

[danwlx]

Thanks for weighing your cylinder Fil. By coincidence I thought that my cylinder had run out tonight, so I weighed it and it' was 20 kg empty but I think it was user error!

[troutie]

is this any good
http://www.uk.airliquide.com/file/other ... t37373.pdf

[Kev888]

Cylinders do vary a bit, so if you can't make out the tare stamp then its probably worth weighing them before starting to empty. Sometimes condensation on the outside can give away the level of liquid left in them, too. The pressure gauges aren't a very accurate guide until close to the end, since the pressure doesn't change a great deal until all the liquid CO2 is gone - whilst it does change with temperature.

Unless you have a leak, I'd expect a pub-sized tank to last for months in normal homebrew situations.

Cheers
Kev

[Brighteyebeer]

Hi Dan
Markings refer to Tare Weight and Gross Weight. Pub-size cylinders are given as 6.35kg, which is the difference between the 2 weights you quote. As has been pointed-out, there will be some variation. Peeling paint, rust etc will change the weights from those stamped on a shiny new cylinder.
I think you'd mislead yourself by putting the keg on scales, then placing too much weight (ahem) on the reading. My last cylinder lasted 19 months - I could've sworn it was empty afer 15 months or so, and I don't believe that weighing it would've left me any better informed.
My own solution to the 'I'm sure I'm running out of gas' syndrome is to keep a small keg to stand-in when it happens. Fire extinguisher, sodastream (with adaptor) lalala will all keep the beer pouring until you have a full-size refill.
Cheers,
Chris