Adding an s30 valve to a firkin

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Active Member
Oct 21, 2014
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Hi everyone. Not sure if the question has been asked before but has anyone ever added an s30 valve to a firkin before? I know it wouldnt technically be classed as 'real ale' but i hate the thought of 5+ gallons going bad because theres no co2 blanket. It would only need a squeeze just to allow the beer to last longer. Any thoughts? Even a smaller 8gram valve would do the job


Well-Known Member
Jun 25, 2013
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Maynard, MA
You won't get much that fits to an S30 valve, although some are available in the UK, albeit expensively - S30 is a proprietary fitting. Practically none are available in the US or elsewhere. If you are outside of the UK (and maybe even if you are in the UK), go for a standard kegging system CO2 tank and regulator, as it's far more compatible with kegging and other uses, and allows you to get CO2 cheaply from welding and bar suppliers rather than expensive cartridges. There are standard fittings for casks to allow CO2 to be added - a search for cask breather should find some ("cask breather spigot" on one US source of UK style casks).

You don't want to pressurize a firkin very much - just half a psi at most. Cask breathers use an even lower pressure regulator - maybe 0.1 psi. But you can cheaply DIY a cask breather using a low pressure LPG regulator, which will be preset to about 0.4 psi. Hook that up to a CO2 source and the firkin's cask breather fitting via gas lines, and it'll keep the CO2 pressure down where it needs to be. It's worth shutting off the CO2 on the high pressure side when not serving just in case of leaks.

A cheaper option, btw, is to use cubitainers - these collapse as you dispense, so you don't need to let any air in. Although that's not a nice as having a firkin.