DIY Party Keg

I made my own party keg for taking beer "on the road" from an unused garden pressure sprayer. If you use postmix kegs you will realize that the 18 litre ones are much cheaper than 5 or 9 litre ones and much easier to get hold of (these two things are probably related). I have never been able to justify the expense of a 5 litre keg. This is my work around.

/!\ WARNING gases don't like being confined to an enclosed space under pressure. They are always trying to get out and when they do, can come out with explosive force.

I am by no means the first person to attempt this stunt. One other reference I found is at oz.crafterbrewer.org. I took a slightly different tack to Graham's keg, I wanted to attach a standard postmix quick disconnect to it so I could:

  1. Use my existing pluto gun
  2. Fill it keg-to-keg via the liquid QD's.

Here is the stuff I used:

  1. 5 litre garden spray from Bunnings ($10). It actually holds more like 8 litres but you need to allow for headspace anyway.
  2. Car valve (solid, racing style makes it go faster) for pressurizing. I had one kicking around but they are probably about $5 (I seem to recall grabbing one for nicks at the tyre shop).
  3. Postmix liquid quick disconnect from LHBS (around $15)
  4. A lump of solid brass, stainless steel or even plastic to make a "plug". This plug fills the hole left by removing the original handpump and which the QD screws into. I machined this on a lathe, it didn't take that long but if you don't have access to one then you will have to improvise.
  5. O-ring to suite plug.
  6. Teflon tape to seal QD thread.
  7. Stuff for dip tube.

Here is one I prepared earlier. It is probably a good idea to give everything a real good clean. The spayer here is HDPE which is the same material that plastic fermenters are often made from but it is not designed for food applications so don't make any assumptions about what state of cleanliness it is in.

Here is a close up of the external additions. The car valve is simply screwed under the existing cap. As it turns out the stepped rubber washer that comes with these style of car valves fitted this particular model of garden sprayer nicely to make an airtight seal.

I can connect a tyre chuck to my CO2 outfit by way of a CEJN compressed air coupling. Updated gas in, see below.

The quick disconnect is screwed into the plug I made of brass. The thread happens to be 1/2" BSP (or possibly NPT). I cut the thread on a lathe (14 TPI), I went a bit deep but nothing that a few layers of teflon tape couldn't seal.

The adaptor plug I made for the quick disconnect. I turned it from brass. I also made a stainless steel one but I haven't tackled the threaded hole yet. If I knew all the dimensions then I would provide them here, but basically I just made it to fit. The important thing (as far as fitting this particular garden sprayer goes) is the thickness of the flange which the o-ring presses against. The o-ring gets pressed against this flange when the pump housing (not shown) is screwed up into the lid. Having said that, no great precision was required to make it all go together and stay gastight.

I also haven't shown the dip tube. The threaded hole goes all the way through the plug so I can just use standard fittings inside to use my choice of BEVA or copper dip tube.

Schraeder Valve for CO2 In

The tyre valve works fine but if I want to leave the gas connected, a more positive connection would be nice. The most recent addition is a schraeder valve from a refrigeration parts store (Refrigeration Parts Victoria).

As far as I can tell, this is the same as a car valve but is designed to mate with filling tubes under pressure. I bought a filling tube, dismantled it and reattached the business end to some BEVA tube that fits into my CO2 regulators.

Valve with its dust cap screwed on. It is pretty much a fancier version of a car tyre valve.

The connector I removed from a filling tube and reattached to BEVA tubing.

What it looks like all screwed together.

I don't recommend you pressurize the vessel just to see what pressure the relief valve opens at. In fact I am not recommending anything here - just some info on crazy stuff I have done. Pressure vessels are generally stress tested hyrdostatically, ie filled with water so that when they rupture, there is no explosion. I don't intend putting anything more than serving pressure into this keg, say no more than 100 kPa. In contrast to 400 kPa when I want to "crash-carbonate" a newly filled postmix keg).

Soda Stream CO2 Bottle Regulator

To make the party keg a little more versatile, I figured I needed a way to pressurize it. Without some kind of CO2 source it is difficult to serve the whole 5 litres since as the headspace increases, the pressure decreases.

Here is my solution. The regulator was $75 including GST from Victorian Fittings and Sales and is made in Australia, designed for the beer industry. If you want two gauges it is another $25 or so.

The soda stream bottles have a pin valve, simply screwing a regulator on won't get you much gas. I made a little insert from brass to depress the pin as the regulator is screwed down.

Party Keg On Wheels

I was tired of carrying it around in a milk carton so I made this Beer Cart for $8. The keg in this picture is a 7L version without the beer fittings attached (ie its not a beer machine).

paul sorenson

PartyKeg (last edited 2005-04-21 00:00:00 by )