gas line size

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paulg
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gas line size

Post by paulg » Fri Dec 25, 2020 2:01 pm

this is probably a stupid question but here goes.
Is it possible too have to small a diameter gas line?
Let me explain
I have a setup with the standard regulator connected to a secondary regulator and onward to sankey coupler,
I copied peebee set up using hydraulic couplings and pvc line but made the mistake of ordering the hose and fitting as 6mm o.d/4mm i.d.
so instead of the normal internal diameter of about 6mm it is 4mm.My beer line out is standard 5/16" I serve at 8psi as I like my beer with little carbonation.
what i am finding is the gauge on my secondary regulator falls as I serve a beer and them recovers when I stop serving,also the rate of delivery of beer slows up.
I assume what is happening is the pressure inside the keg falls as the beer is served because the gas input cant keep up with the output

I dont want to reorder all the fittings/hose if it wont make a difference as it is quite expensive when shipping is added,it is possible my secondary regulator is faulty

McCoy
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Re: gas line size

Post by McCoy » Fri Dec 25, 2020 10:03 pm

Should be OK, I use 3/16" OD - 1/8" ID tubes without any problems.

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soupdragon
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Re: gas line size

Post by soupdragon » Fri Dec 25, 2020 11:34 pm

Yep, 3/16" gas line in use here too. I'm using beer line without any problems

Cheers. Tom

paulg
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Re: gas line size

Post by paulg » Sat Dec 26, 2020 10:48 am

thanks for the replies,I am going to swap the secondary regulator with another one I have and see if the beer flow rate slows like it does with the existing reg.

Thats the noticable thing,if I draw a jug of beer at first the flow rate is good but then it slows somewhat.the secondary reg gauge also shows a drop in pressure but as soon as I stop serving the pressure rises again slowly.I am now suspecting a sticking reg,maybe it has got beer in it although I dont see how as the keg couplers have duck bill valves in them

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PeeBee
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Re: gas line size

Post by PeeBee » Sat Dec 26, 2020 12:54 pm

Cor, It's got my name on it! I'd better do a bit of "technical support":

I think the others here have convinced you it has nothing to do with restricted flow due to 4mm ID tubing. If there was such a restriction, the keg pressure would catch up within a second anyway. 3/8" tubing will happily support numerous kegs in a large Pub serving virtually constantly and several bar staff present so several beers being served at the same time. At home we don't have an environment like that (usually!).

The pneumatic tubing is polyurethane, not PVC, by the way. Polyurethane is great for gases (and a lot more flexible than the nylon that was much used in pneumatics) but do be careful using it with liquids; it appears there are two "types" of polyurethane tubing, and one type is not very resistant to liquids. Because it is so supple it is possible to crimp it shut (in a door, too sharp a bend, etc) which is difficult to locate because it will spring back in shape when the restriction is removed. The tubing can also be damaged by such abuse (split), also difficult to locate because it will spring back in shape when the restriction is removed.
Cask-conditioned style ale out of a keg/Cornie (the "treatise"): https://drive.google.com/file/d/0BwzEv5 ... rDKRMjcO1g
Water report demystified (the "Defuddler"; removes the nonsense!): https://drive.google.com/drive/folders/ ... sp=sharing

paulg
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Re: gas line size

Post by paulg » Sat Dec 26, 2020 4:18 pm

I am only using the polyurethane tube on the gas side ,the beer side is what came with my beer fridge (clear flexible )'
the gas side is all external to the fridge apart from the 3 lines that feed the 3 sankey connectors ,they feed through a hole at the rear of the fridge.
i am using the
https://www.shako-online-sales.com/frl/regulators/NR200
regulators as my secondary ones on 2 lines and a propane adjustable reg on the other for by beer engine
I an using 20psi on my primary reg ,should this be higher?

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PeeBee
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Re: gas line size

Post by PeeBee » Sat Dec 26, 2020 6:18 pm

paulg wrote:
Sat Dec 26, 2020 4:18 pm
I am only using the polyurethane tube on the gas side ,the beer side is what came with my beer fridge (clear flexible )'
the gas side is all external to the fridge apart from the 3 lines that feed the 3 sankey connectors ,they feed through a hole at the rear of the fridge.
i am using the
https://www.shako-online-sales.com/frl/regulators/NR200
regulators as my secondary ones on 2 lines and a propane adjustable reg on the other for by beer engine
I an using 20psi on my primary reg ,should this be higher?
Probably (and quite likely your problem!). Oddly I can't find the maximum input pressure for them Shako regulators just now, but I suspect it's about 10BAR. The propane adjustable regulators should take 10-16BAR (the Clesse ones I use take 16). If you are not needing the 20PSI for something else, ramp it up! I run my secondary regulators from 5BAR (75PSI) supplied by the primary regulator (a diminutive fixed output jobbie).

Regulators will respond more snappily if the input/output ratio is fairly high (within reason, the huge input/output ratios of the primary, or cylinder, regulator is the reason that get so iffy trying to get as low as 10PSI out of them). CO2 cylinder is roughly 57BAR or 850PSI.

(EDIT: Shako put all there limits out as kgf/sq.cm: 1kgf/sq.cm is about 0.98BAR, so near enough same thing).
Cask-conditioned style ale out of a keg/Cornie (the "treatise"): https://drive.google.com/file/d/0BwzEv5 ... rDKRMjcO1g
Water report demystified (the "Defuddler"; removes the nonsense!): https://drive.google.com/drive/folders/ ... sp=sharing

paulg
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Re: gas line size

Post by paulg » Sat Dec 26, 2020 7:38 pm

thanks peebee I will ramp up the primary pressure a bit,my adjustable propane reg is the one you originally recommended 0.5-2 bar not the later one with more output pressure

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PeeBee
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Re: gas line size

Post by PeeBee » Sat Dec 26, 2020 9:17 pm

paulg wrote:
Sat Dec 26, 2020 7:38 pm
thanks peebee I will ramp up the primary pressure a bit,my adjustable propane reg is the one you originally recommended 0.5-2 bar not the later one with more output pressure
Both those Clesse one's take up to 16BAR. The 50-150mbar ones (which you've got and are perfectly adequate) and the 20-300mbar ones I dug out later. Actually, I've been getting reports that those higher-pressure ones can still come with the POL adapters attached, and they are a pig to remove! (7mm allen key, for anyone who gets one).
Cask-conditioned style ale out of a keg/Cornie (the "treatise"): https://drive.google.com/file/d/0BwzEv5 ... rDKRMjcO1g
Water report demystified (the "Defuddler"; removes the nonsense!): https://drive.google.com/drive/folders/ ... sp=sharing

paulg
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Re: gas line size

Post by paulg » Mon Dec 28, 2020 10:15 am

i have done some more investigating and it looks like the secondary reg is the problem.I swapped the two beer lines over,so that the suspect one was on my carbonation line and found that the gauge didnt move when I served beer now.
I have also been losing gas for a while ,when the system was turned off the pressure on the main reg has been dropping overnight.
I have today dismantled everything and submerged the secondary reg in water and found the suspect one is bubbling from around the adjustment knob.
I have bypassed it for now and will order a new one

paulg
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Re: gas line size

Post by paulg » Tue Feb 02, 2021 8:09 pm

just an update
I have swapped out my micromatic secondary regulators for Classe 0.35 to 2 bar propane regulators and now have them set at 5 psi ,they are staying steady at this reading and with the gas turned off the gauges havent moved in 4 days so no leaks.
I have also swopped the beer line to 1/4 i/d from 3/16 and can get a good speed pour at these low pressures with about 4 feet of line,giving me almost beer engine carbonation without the need to waste the first 1/2 pint every evening from the beer engine cylinder when maybe I only drink 2 pints


Thanks to PeeBee for the tech support :D

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PeeBee
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Re: gas line size

Post by PeeBee » Wed Feb 03, 2021 11:49 am

paulg wrote:
Tue Feb 02, 2021 8:09 pm
... Thanks to PeeBee for the tech support :D
:beer:
Cask-conditioned style ale out of a keg/Cornie (the "treatise"): https://drive.google.com/file/d/0BwzEv5 ... rDKRMjcO1g
Water report demystified (the "Defuddler"; removes the nonsense!): https://drive.google.com/drive/folders/ ... sp=sharing

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