Medium to long systems using 1/4id tubing
Jeff Stanley
ft with the potential to go 125ft or more.
On my previous post, I described four systems built using 1/4id tubing
rather than the common 3/8id or emerging 5/16id tubing.
In November (05) I completed a system that had a total length of 96
feet using 1/4id tubing without utilizing beer pumps. The system
operating pressure was 22psig.
This could not be done without the use of the new Perlick faucet. The
new Perlick faucet uses a ventless design and the shut off is at the
front of the faucet resulting in a more sanitary device. The outlet of
the faucet is smaller in diameter and allows for a smoother pour at
slow-ish flow rates (below 110oz/min).
>From my experience in my local market these faucets created trouble on
Perlick-designed systems. I was anti-new-perlick-faucet til I fiddled
around with them for a bit.
Perlick's in-house-designed systems utilize 3/8 id trunk line that
demands a flow rate as high as 130-135oz/min for somewhat-satisfactory
packing performance. Even at high flow rates, a 'smart coupler' or FOB
Stop device is necessary to salvage beer during keg changing. The new
Perlick faucet does not operate well at this flow rate. At flow rates
above 110 oz/min, the beer leaves the new Perlick faucet with quite a
lot of force and the beer twirls as it leaves the faucet unless the
beer glass is actually pressed against the faucet nozzle.
In my opinion/experience, because of the above issues, the Perlick
faucet is problematic in Perlick systems.
I played with the Perlick faucet for a couple of hours because of some
problems in a Perlick-installed direct draw system using the new
faucet. This direct draw system had 36 lines coming from a large walk
in cooler with the shanks installed into the side of the cooler. The
bar is adjacent to the cooler. The system uses a blend gas system
consisting of a McDantim blend panel and a Perlick Nitrogen generator.
When Perlick finished the install (which was partially designed by Ted
Bax, who knows better, and wanted nothing to do with the finished
product) it had all 36 lines connected to a 5ft long 3/16id vinyl line
leading directly to the shank nipple. Even an amateur installer can
see that this system has a (traditional restriction method) 1gallon/min
flow rate @ 15psig. Because this system uses blended gas, it should
have had a much higher operating pressure in order to take advantage of
the blended gas itself (if the reader doesn't understand this, go to
mcdantim.com and read "beer gas 101").
Just (attempting to) set up this system taught me that the new Perlick
faucet design changed traditional restriction and flow rate principles.
It was obvious that any pressure in the system over 10 or 12 psi
caused a very large amount of force at the end of the faucet. The
Perlick faucet didn't like higher flow rates that would be acceptable
with a traditional beer faucet. Another puzzling thing about this was
that at 10psi, the flow rate through a traditional faucet would have
been lower than it was through the new style faucet. Because of this I
concluded that the traditional faucet had a restriction value which
none of us was really considering, but was kind-of built into the
numbers we all use for our beer lines.
OK, back to the drawing board, let's experiment!
Because the system had individual regulators on each line I just tried
different things. The first thing I did was take out the 40% CO2 blend
panel and replace it with a 60% CO2 panel (thank you McDantim for
making this easy and thank you Perlick for solving this issue in you
system design in later systems). I then raised the pressure on my
experiment line to 23psig giving me a partial pressure of about 8psig
of CO2 ( [23+14.7] * 60% = 22.62 , 22.62psia = 7.92psig). 8psig of
CO2 is enough to maintain carbonation over a reasonable dispense time
and 23psig of mix-gas is enough to take advantage of using mix-gas in
the first place; hell this retailer probably had $5000 or more just in
the gas system of this mess.
After getting my gas dialed in I went to work to determine how much
line-restriction would be necessary to balance the system using the
new-style faucet. I ended up using 15feet of 3/16 vinyl hose. No, I'm
not kidding, 45lbs of traditional restriction to balance 23pounds of
gauge pressure. Anyhow, a few weeks later I rebuilt all of the lines
in that system and it has been trouble-free for about 18 months now. I
put about 35 man-hours in the job but I learned something very valuable
which Perlick has yet to get through their heads.
Back to my 100ish ft glycol system using 1/4id hose.
When I bid this system I gave the retailer a price high enough to
install beer pumps if I needed to, just to cover my backside. Then I
built a long version of my incredibly simple glycol dispense system:
McDantim 60% CO2 Blender
5/16id 6ft jumper
SS Wall Bracket
90ft 1/4id trunk line
NO choker line
Perlick Century tower
Perlick new-style ventless faucet
so... we have a couple pounds of restriction in the jumper and tavern
head (D-System coupler), 7 pounds of restriction in the stainless steel
tubing of the tower, about 4 ft of v-rise so add another couple pounds
of restriction, and 27 pounds of restriction in the trunk line (
0.3lbs/ft times 90ft). A total of 38lbs of restriction.
Shouldn't work without pumps, we would never put 33-38 lbs of pressure
into the keg, we would get dissolved N2 problems wouldn't we? Well, I
had already played with the previous system described above and got an
ideal flow rate at 23psi using 15ft of 3/16 vinyl hose so I wasn't sure
what would happen.
That friggin beer poured BEAUTIFULLY at 22psi. I'm telling you, it was
art! Takes less than a pint glass of foam to pack craft beers. Takes
about a half pitcher of foam to pack fizzy light lagers, who needs a
friggin smart coupler or FOB -stop device!
Anyway, I haven't had any trouble in past systems as high as 30psig
operating pressure. I am guessing that a system similar to the one
just described could go another 25ft and still stay under 30psig
operating pressure.
I only wish I had a keg I could sacrifice and go back to our
warehouse-cooler to find the limits of this design.
A couple of notes:
I have given up on rebuilding hollow forced air towers for glycol use.
They never work nearly as well as the Perlick or Micro-Matic Glycol
towers.
The Perlick glycol tower has only 7lbs of restriction in its stainless
pipes, the micro-matic has 22lbs of restriction in its pipes. The
perlick century glycol tower also comes with the ventless new-style
faucet installed. Because of this I am planning to use the Micromatic
tower on systems under 75ft and the Perlick in systems over 75ft, for
obvious reasons.
Simple
Affordable
Quality beer
Good temperature
Easy effective line cleaning (6ft/second flow using a CO2 pot)
Cheers!,
Jeff