Retractable CO2 Lines
I’ve been driving my brewery design for many years now. The push for convenience, storage organization, ease of use, and aesthetics are all considered as I design, build, and implement. My cold room, malt mill, kegerator, and digital tap handles have all been presented in previous BYO articles (links provided later, if you’re interested). The project in this article came from the inconvenience of having to carry my recently filled kegs into the cold room to pressurize and purge with carbon dioxide (CO2).
One of the keystones of my cold room design was to have an external gas cylinder plumbed in from outside (stowed in my attic). This concept allowed me to maximize space and organization in my cold room, distributing CO2 via various tees, manifolds, isolation valves, and ball-lock connections. This worked great until I grew tired of lugging unpressurized kegs into the cold room after filling . . . not to mention bringing the kegs in prior to filling to purge out any oxygen. Having a small, portable tank to carry around my brewery wouldn’t suit my (admittedly, high) standards.
I elected to tee off my source tank in the attic and plumb my gas lines over to where my fermenting fridge and conical fermenter are located. Note that I keep my main lines’ primary regulator at 3 bar (44 psi), which is my max desired carbonation level for my annual batch of Cedric’s Rhubarb Sparkle, and regulate down with secondary regulators for all my kegs. I have two lines from this point in the ceiling, one to a precision low-pressure regulator for my Blichmann Fermenator V4. The other line is a retractable coiled tube for purging and filling kegs. It remains at the main pressure, as a little extra oomph is welcome when purging kegs or over-pressurizing a new batch with minimal headspace.
The total cost of this build I estimate is under $150, with the bulk of the cost being the retractable line and tubing.
If you’re interested in the other builds of mine featured in BYO, here are the links:
Cold Room: www.byo.com/article/building-a-cold-room/
Malt Mill: www.byo.com/article/build-a-better-grain-mill/
Kegerator: www.byo.com/project/kegerator-tower-cooling-an-alternative-chilling-system/
Digital Tap Handles: www.byo.com/project/e-ink-faucet-handles/
Tools & Materials
• Polyurethane 3⁄8-in. tubing (100-ft/30-m bag)
• Polyurethane 1⁄4-in. tubing (100-ft/30-m bag)
• Polyurethane 1⁄4-in. coiled tubing
• Push-to-connect 3⁄8-in. tee
• Push-to-connect 3⁄8-in. to 1⁄4-in. plug adapter
• Push-to-connect 1⁄4-in. tee
• Push-to-connect 1⁄4-in. wye
• Push-to-connect 1⁄4-in. check valve
• Push-to-connect 3⁄8-in. bulkhead fitting
• 2 barbed 1⁄8-in. to SAE45 1⁄4-in. flared fittings
• 4 Oetiker clamps 5.8–7 mm
• Ball valve 1⁄4-in. tube
• Ball-lock gas connector
• Ball-lock liquid connector
• 2 socket head cap screws M4x0.7×15
• 2 nuts M4x0.7
• Rectangular magnet
• Retractable laundry line
• Shaft collar for 1⁄16-in. cable
Step by Step
1. Preparation/Plumbing
Shut off your CO2 tank and close all your isolation valves. Depressurize the system via a pressure release valve or a ball-lock fitting. Lock out as needed to prevent accidental pressurization. Locate the position where you want your lines coming through your wall or ceiling. Drill a clearance hole larger than the diameter of your bulkhead fitting. A Forstner bit is ideal, or a hole saw as a second choice. Watch out for your studs/joists, and take care not to punch through the back of the hole too hard.
Cut into main CO2 line and add a push-to-connect tee. Run your new line as desired and plumb into one end of the bulkhead fitting. Connect tubing to the opposite side of the bulkhead and route as needed. In my case I stepped down from the main line 3⁄8-inch (9.5-mm) tubing to 1⁄4-inch (6.35-mm), and teed off for the fermenter line. Connect the coiled tubing at this point, and let it dangle into your brewing area. The tubing I selected is from Freelin Wade and is flexible and reliable. Buyer beware — go with a reputable supplier. If you use to a cheaper version you can end up with a stiff or cracked tube. Youch!
2. Retractable Line
Since the coiled tubing is so loose, it won’t naturally return to its tightly coiled state. I kludged together a scrapped retractable laundry line. I made a plywood mounting bracket (2a), and securely mounted the mechanism, then screwed it to the ceiling (2b).
3. Determine Line Length
I then pulled out the cable to my required distance and installed a shaft collar to lock it from retracting further. I inserted the cable through the coil, and used two Oetiker clamps to bind the coil tube end to the cable. The extension is now ready for testing. I recommend ensuring your retractable laundry line is 12–18 feet (4–6 m). My usage varies between filling at my sink during sanitizing and purging between kegs, to filling closer to the cold room – either way the extra reach is awesome.
4. Ball-lock Connections
To prevent leaks, I used a ball valve after the coil so I can locally shut off the gas. In general, you should always use a check valve before an end-of-line, which is more important at the keg-side to prevent an empty tank from pulling carbonation from a filled keg. Next, I attached a push-to-connect wye and two short lengths of 1⁄4-inch tubing. I placed an Oetiker clamp on each tube, and inserted the barbed end of the SAE45 (aka MFL 1⁄4”) fittings. Actuate the clamp with a pex ratcheting plier or end-nipper pliers. Thread on your CM Becker ball-lock connectors as usual, and tighten snug with a wrench.
5. Finishing
The wye near the end of the line has two small mounting holes. Insert two M4 socket head cap screws and nut the ends. Mark the wall where the cap screws touch the wall and screw the rectangular magnet to the wall in that spot. You now have a handy dandy magnetic wall mount for your retractable CO2 line.
You can now turn your carbon dioxide tank back on and purge out any potential oxygen ingress in the lines. Your newly installed lines will certainly need a thorough purge. Open any remaining isolation valves to get everything back online.
6. Testing
Pull your retractable line off the wall and put it back. Give it a stretch. Purge some kegs. Put it in some milk and make bubbles.
Congrats! One last bonus for you if you’ve made it this far: Turn off the valve and put a spare 8-inch (20-cm) piece of tubing into the wye, and purge it. You’ve now got a very handy CO2 purge for your hop pellet bags prior to resealing.
