Gas lines

[mfroes]

It just came to my attention that I have been using the same hose for liquid and gas.
What do you guys use as gas lines?
Just a regular clear pvc from bunnings would be ok?
My big co2 canister which I use for carbing has the lines all kinked and it's time to change.

Cheers

 

[meathead]

You can pretty much use whatever you like as long as you can seal it

 

[phildo]

One of the lines off my Manifold is the 6mm pvc tubing from bunnings the other three lines are the normal polyethelene tubing cut to the shortest length possible (just long enough to to set the keg down just outside the fridge.

I prefer the Polyethelene over the pvc because I trust it more.

 

[Maheel]

i use beer tube , is that bad ?

 

[phildo]

Same thing, generally the difference is the inner diameter of the tube. Most tube has an outer diameter of 8mm and generally an inner diameter of 4mm, 5mm or 6mm. I use 4mm ID (8mmOD) for the liquid side, 6mm ID (10mm OD) from the regulator to the Manifold and 6mm ID (8mm OD) for gas to the keg.

Beer line is perfect for gas lines. The inner diameter doesn't really matter when it comes to gas you just want it to be really tight around your barbs although you will only get 5mm or 6mm to cooperate with barbs. You will get better airflow with a larger inner diameter but we are just pulling beers here.

 

[phildo]

I use a 4mm ID for the beer side to control foam and you can serve at higher pressure which is good for higher carbonation levels and you can have shorter beer lines if that's a thing for you. If you use the 4mm tho you will need to use push in fittings, they bring extra costs to your build but many benifits

 

[MHB]

I use the same line as for the tap run (Flexmaster 2) mine is all 6mm duel layer (Nylon inside, Polyethylene outside).
Pressure or flow resistance is really just a matter of line length and internal smoothness, Nylon is very smooth so gives less flow resistance (means you need more length to control fobbing (FOB - Foam On Beer)), which might be the only downside of Nylon or duel layer lines.

Up sides are better hygiene (less bacteria and yeast stick to the surface or imbed in the plastic), less flavours and cleaning chemicals penetrate the nylon than do plastic, it opaque to Oxygen...

On balance having to use a bit longer 6mm line is pretty cost neutral when compared to using the more expensive fittings required when using smaller line, (the barbs on the disconnects are all 6mm)
Same advantages apply to using good quality line for the gas supply, I wouldn't use PVC, it can get contaminated very easily if you ever get a bit of beer up the line (who hasn't), it can smell of PVC (not a good beer flavour), PVC is rated to a much lower pressure, it wont last as long (cheaper up front, costs more long-term, especially if you ever get a leak and loose a bottle of gas), I only need to keep one type of line and clamps in stock for emergences.

Just on the size thing, beer line is always given in Inside/Outside Diameter, so its 4x7 (4mm ID, 7mm OD), 5x8 and 6x10 being the common sizes used by home brewers. most PVC is given in OD so 10mm has a bore of a bit under 8mm (10mm - 2x wall thickness).
Beer line comes in four grades that I know of
Crap PVC - mostly supplied with the cheapest possible option dispense equipment.
Polyethylene - better than PVC but not as good as duel layer or Nylon, more flexible, but wont last as long.
Solid Nylon - best for fixed install, expensive but will last virtually forever, not very flexible and not all that good for anything that moves.
Duel Layer - Compromise, benefits of both Polyethylene and Nylon, without most of the disadvantages.
Mark

 

[akx]

I just built my keezer. I used bevlex for the gas lines to avoid kinking, and valpar flexmaster for the beer lines to avoid any off flavours. Not sure if those are best, but so far they're working well.