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So we all must switch to SS lines
Simple
Expensive, & difficult, but problem solved.
Simple
Expensive, & difficult, but problem solved.
how many decades has vinyl lines been the norm? I don't get why suddenly EVA lines are a must.
Actually, I am one of those that uses 1/4 ID line. I use 10 ft per keg, and am only traveling a short distance....say, 2 feet. Perfect pours every time.If you took a poll I bet 90+% of folks are using 3/16" ID beer line over 1/4" barbs.
It's been a hot minute since I built my setup, and I do believe that I am wrong in my post. I think I DID in fact use 10 ft of 3/16. I am in the process of replacing my lines, and I do believe that I may have ordered 20 ft of the wrong stuff. Soooooooooooo, my bad.I did allow for 10%-.
But the physics say you're on your own island...
Cheers!
[...]I think I DID in fact use 10 ft of 3/16.[...]
... I wasted half the keg figuring it out...
In regard to this scenario I have another question.Imagine you have 50 guys (CO2) on one end of a football field, shooting BB guns. On the other end, you have 1 guy (O2) shooting his BB gun back at them. Gas particles are so small, with such a huge area around them, that it is very unlikely that any of those BB's are going to collide and knock each other off course. It might happen every once in a while, but most of them are going to get through.
Forget the BB's. Let's just focus on gas molecules. If you have a pipe connecting a CO2 tank (on the left) and an O2 tank (on the right), and both tanks are at the same pressure, then no "wind" flows thru the pipe. However, the individual gas molecules are bouncing around like crazy. If you look at a particular position along the pipe, there will be higher O2 concentration to the right, and lower O2 concentration to the left. All the gas molecules (both CO2 and O2) are bouncing randomly back and forth across the invisible plane at the particular pipe position. Since there are more O2 molecules on the right of the plane, more O2 molecules cross the plane from right to left, than cross from left to right. The opposite happens with the CO2 molecules. Because more O2 crosses the plane from right to left, the concentration of O2 increases on the left. This same phenomenon happens at every position along the pipe, so O2 slowly moves to the left, and likewise, CO2 moves to the right. This is diffusion. The rate of diffusion is affected by the total pressure, since the higher the pressure, the more molecules there are in each cubic inch, and the higher the density of molecules, the more often a molecule will bounce off another molecule. The more often molecules collide, the shorter distance they travel between collisions, so it takes longer to travel a distance many times longer than the "mean free path" (average distance between collisions.) Thus diffusion is slower at higher total pressures.In regard to this scenario I have another question.
What if there was a strong wind blowing from behind the 50 BB gun shooters in the direction of the lone BB gun shooter? Where the Co2 under pressure were to represent the strong wind blowing at the lone shooter. I believe quarks can pass through solid steel as easily as they can the atmosphere. But it's hard for me to wrap my head around how O2 at atmospheric pressure can penetrate vinyl tubing filled with Co2 inside that is under pressure.
Of course I have no way of telling how this all works and I have replaced my old vinyl lines with EVABarrier double wall tubing in any case. Better to be safe than sorry.
This is diffusion. The rate of diffusion is affected by the total pressure, since the higher the pressure, the more molecules there are in each cubic inch, and the higher the density of molecules, the more often a molecule will bounce off another molecule. The more often molecules collide, the shorter distance they travel between collisions, so it takes longer to travel a distance many times longer than the "mean free path" (average distance between collisions.) Thus diffusion is slower at higher total pressures. ... the diffusion velocity.
You could do this if you knew the diffusion coefficient for O2 thru the tubing material. For multi-layer tubing, each layer will have a different diffusion coefficient. You also need to know the thickness of each layer.@Dland not being familiar with the formula in your post myself, I would guess you could also use it to estimate the rate at which O2 from the atmosphere would penetrate the beer line to the point were the beer inside it would become oxidized. Oxidized to the level at which off flavors are detectable by the average craft beer lovers' palette. That formula if written would provide us with perspective as to how long it takes for O2 to degrade our beer. Thank you for sharing your gas diffusion expertise with us.
A typical 3/16 inch inside diameter beer line having an outside diameter of 7/16 inch. Similar to Bevlex 200 PVC 1/8 inch thick wall tubing. What would be helpful is knowing how long it would take O2 to penetrate the tubing to the point where off flavors are detectable. Whether it would take days, weeks, months or years of O2 seeping into the beer before its flavor is adversely impacted.You could do this if you knew the diffusion coefficient for O2 thru the tubing material. For multi-layer tubing, each layer will have a different diffusion coefficient. You also need to know the thickness of each layer.
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