EVABarrier Resistance per foot?

[MrBJones]

Just what is the resistance of 3/16" EVABarrier? Some posts on HBT seem to say it's about 1 psi per foot, but others say that they use lengths as short as 4 or 5 feet for everything; still others say they use 10 feet or more. Meanwhile, Williams Brewing's website says 2.8 psi per foot. Which is it?

Also, would it be practical to splice pieces of tubing using Duotights to change line length... maybe start with 5 foot lengths and then add 2 foot lengths as needed on a particular line.

 

[day_trippr]

There is no true 3/16" ID EVABarrier tubing as it's a hard metric product.
There is 4mm ID, 5mm ID and 6mm ID.
From experience, I would rate the 4mm ID at 2 psi per foot.
From math, I would expect the 5mm ID to be 1 psi per foot - very similar to solid PVC 3/16" ID resistance (0.1968" vs .1875").
fwiw, I run a little over 6' of 4mm per faucet at CO2 pressure of 11 psi at the kegs (pales and such) and 9' of the same line for my 15 psi beers (eg: wheat, saisons, etc).

Cheers!

 

[Bobby_M]

Splicing is counter productive because the turbulence you add will knock CO2 out of suspension. Use the 4mm EVA and 5-6 feet is plenty for most beers.

 

[odie]

I run 10ft lines on all my taps. As stated, splicing is counter productive to preventing foam...

You could swap out lines as needed but then you have an issue of stuff growing inside you lines when not in use. That line is going to be a breeding ground while it's in storage with any residual moisture and a nice dark closet.

Since I brew many styles and change kegs out often with different beers all the time...I chose to just run lines long enough for my higher carbed beers like Hefe and Pils, sometimes close to 15psi. I get good pours and when I run ales, IPAs, brown ales, stouts, etc at lower psi the pour is really not that much slower.

 

[MrBJones]

According to the charts, at 45 degrees I'd need nine pounds for 2 volumes and 21 pounds for three volumes. Suppose I size all lines for 15 pounds? Anything with less than 15 pounds wouldn't need any extra FC resistance. Anything above 15 and the FC could dial it up. Would I be able to get a smooth pour at the high end?

 

[Deadalus]

Fittings also reduce pressure. I looked at a chart for 3/8" pex and it said a coupling was the equivalent of 2.0 feet of 3/8" tubing. It'll be different values for the Duotight and Evabarrier of course, maybe it's available somewhere.

 

[MrBJones]

According to the charts, at 45 degrees I'd need nine pounds for 2 volumes and 21 pounds for three volumes. Suppose I size all lines for 15 pounds? Anything with less than 15 pounds wouldn't need any extra FC resistance. Anything above 15 and the FC could dial it up. Would I be able to get a smooth pour at the high end?

Just to clarify, I'd use flow control faucets to add extra resistance when the line doesn't provide enough.

 

[Bobby_M]

Fittings also reduce pressure. I looked at a chart for 3/8" pex and it said a coupling was the equivalent of 2.0 feet of 3/8" tubing. It'll be different values for the Duotight and Evabarrier of course, maybe it's available somewhere.

Pex fittings insert INSIDE the tubing so it chokes it down. Duotights seal on the outside. I doubt the fittings add anything in this case.

 

[Deadalus]

Pex fittings insert INSIDE the tubing so it chokes it down. Duotights seal on the outside. I doubt the fittings add anything in this case.

While I agree with your point, it's not nonexistent. Copper is pretty easy to get a square cut on the tubing, but pvc not so much using a hand saw for instance and flexible tubing worse so. It does not end up perfectly smooth inside there even with the best of intentions. A coupling is probably the least loss of any extension type fitting, it has no bend, but even a small equivalent like 0.5 ft is a lot compared to a 2' extension.

It would be nice to see a chart with various fittings but I was unable to locate one for push-to-connect. I'm more interested in the value for a 90.