DuoTight sizing for gas line?

[Albionwood]

Wondering if there is an advantage to using different size lines for gas and beer with the DuoTight system, or just use one size for both. I'm setting up a bar for a BBQ and will have about seven different beers on tap, with the gas lines running up to eight feet from the regulator. Last year I used the 8mm tubing for both gas and beer, and noticed a drop in pressure when we had two taps going at once (which is most of the time). As the kegs got drawn down so there was more gas in them, that problem mostly went away - it really was mostly noticeable right at the start when the kegs were full.
After that I am wondering if I should get 9.5mm tubing and fittings for the gas side, and keep the 8mm for the beer side. How much difference will that make though? It's certainly simpler to just use 8mm for everything.

 

[BongoYodeler]

Wondering if there is an advantage to using different size lines for gas and beer with the DuoTight system, or just use one size for both. I'm setting up a bar for a BBQ and will have about seven different beers on tap, with the gas lines running up to eight feet from the regulator. Last year I used the 8mm tubing for both gas and beer, and noticed a drop in pressure when we had two taps going at once (which is most of the time). As the kegs got drawn down so there was more gas in them, that problem mostly went away - it really was mostly noticeable right at the start when the kegs were full.
After that I am wondering if I should get 9.5mm tubing and fittings for the gas side, and keep the 8mm for the beer side. How much difference will that make though? It's certainly simpler to just use 8mm for everything.

I use the same size lines , 8mm, for gas and beer. Works fine so I never changed. Why buy and stock two different sizes when one size does the job…

 

[day_trippr]

Wellll....

I went with 5mm ID for my gas lines as when I converted my entire cold side beer, gas and rinser water feed to Evabarrier tubing I still had an 8-way barbed manifold and three barbed primary regulators, and the 5mm tubing is that much easier to warm up and shove over a 1/4" barb. As it took almost four full rolls of tubing to convert everything the opportunity was there for the exploiting.

I've since replaced the manifold with a 10-way MFL model and re-valved the primaries with MFLs, so everything is on PTCs except for my beer gas line (from a Micro Matic primary with their 3/8" barb )...

Cheers!

 

[doug293cz]

A temporary pressure drop while serving will not affect the carbonation level of the beer. So, the only thing to worry about is if you are having trouble keeping the beer pouring. If the beer pours, then no need to increase the gas line ID.

Brew on