Choker selection

[Ogie]

Aspetz, sorry didn't see your comment until tonight. I'm curious about your restriction math. My calculations (based on the BA Draught Quality Manual) are as follows:

11 ft rise (0.43 # / ft.) = 4.75 lbs
6 ft jumpers, 3/8" EJ Ultra Barrier hose (~0.10 # / ft.) = 0.60 lbs
10 ft trunk, 1/4" barrier tubing, (0.30 # / ft.) = 3.00 lbs

Without chokers, that's only 8.35 lbs of resistance. I'm curious how you calculate twice that resistance?

[Aspetz]

doing the restriction math, as described, your system has ~16lbs of restriction without any choker. you'll have to explore using a blender to get your dispense pressure to 18 or 20psi (i religiously recommend 60/40 blends) restrict to 22lbs and dispense at 20psi. In my experience the Ej Bev and Micro Matic flexmaster 3/16" are ~2lbs/ft

[Ogie]

Well, that was a fail.

Since 3/16" PVC is ~3# / ft draft resistance, that should be ~36# at 12 ft. I thought I could measure the resistance of the hose similar to determining the wetting pressure of a carb stone... just increase pressure on a keg of water until flow initiates, and then divide the pressure by the number of feet. Nope. Fluid flows through the hose with even the slightest pressure. Hose was kept at zero lift or drop.

Thoughts?

Maybe I could attach a water pressure gauge at the end of the hose and measure a pressure drop?

[EDIT] Nevermind. I guess I didn't google the proper search terms before (even though I spent a couple of days searching the tubing specs). Searching JUST "3/16" barrier resistance" led me to MoreBeer and another home brew site, both stating that the Ultra Barrier Silver has 2.2 # / ft. resistance. That seems in accordance with online statements that using this hose in a kegerator required increasing the tubing length for proper pours.

[Ogie]

Hello,

Designing my draft delivery. I planned to use PVC free, BPA free tubing. Looking at EJ Brew Ultra Barrier (not the Silver Anti-microbial).
https://d2jug8yyubo3yl.cloudfront.ne...4d1db7d2b2.pdf

The 3/8" jumpers are easy to calculate using the average resistance spec for barrier tubing.
My issue is calculating the 3/16" choker lengths. The internet is loaded with comments about the resistance being much lower than the 3#/ft spec for vinyl. The manufacturer doesn't offer a fluid resistance spec.

Does anyone else use 3/16" barrier for chokers? A different vinyl alternative? Is vinyl "leaching" less of a concern than I've read??

DETAILS:
Cold room is below taps. 11 ft. rise (ctr of keg to faucets)
8 ft. trunk with 10 product 4 glycol
6 ft. jumpers
Choke lines 24" min - 32" max (from trunk connectors to shanks inside tower unit)

Alternately, I've considered ordering 12 ft. and measuring the pressure threshold required to initiate water flow.