Hooking up EVABarrier tubing to a 5/16" barb input?

[Horseflesh]

I realized my CO2 manifold already has flare fittings, so I'm making the switch to EVABarrier.

However, the manifold input is a 5/16" barb, as is the output barb on the reg.

What's the best way to get DuoTight fittings in these spots? Can I just unscrew the barbs and replace them with this? Somehow the non-flare side doesn't look quite right though.

Same thing without check valve appears to be here: Brass Flare Fitting - 1/4 in. Flare x 1/4 in. MPT | MoreBeer

And, if I got an adapter that did not come with sealant, what should I use? I see regulators assembled with both Teflon tape and the dried up liquid sealant.

 

[day_trippr]

It's highly unlikely you can remove half that valve assembly and replace it with something that sports a flare thread instead of the barb - it's a frequent question that afaik nobody has successfully achieved - but, if you do it successfully, let us know I have a Micromatic regulator with a 3/8" barb (wth were they thinking?) that took time, heat and a swaging tool to get 5mm ID EVABarrier tubing to fit. It would have been hella easier to replace the half valve piece with the barb...

Cheers!

 

[Horseflesh]

Thanks! For the regulator side at least, it looks like I have to replace the whole valve assembly with one that has a flare fitting. That should be an easy bolt-on, right?

 

[DuncB]

If it's quarter inch then this could do it.

http://www.ubrew4u.co.nz/product/8mm-Push-Fit-with-1-4in-M-thread

 

[Horseflesh]

That looks like it would work @DuncB but I want a valve at the regulator. Also, that ships from New Zealand!

I emailed Taprite to make sure I can use manifold outlet parts for the inlet. None of their parts say "inlet," but as far as I can tell, they are the same threads.

 

[day_trippr]

Again, the notion of finding a hunk of brass that could replace half of a shutoff valve to switch from barb to 1/4" mfl has been a frequent desire that to my knowledge has yet to be effected successfully. Replacing the entire valve assembly is the only "for sure" way to convert a regulator from barb to flare fitting...

Cheers!

 

[Horseflesh]

Replacing the entire valve assembly is the only "for sure" way to convert a regulator from barb to flare fitting...

Right. That's this, right?

I have been trying to confirm that all the threads on a manifold are 1/4" NPT but I cannot find that written down anywhere... it must be the case, right? It's certainly the case for the outlets and it would be bananas for the inlet to be something just a tiny bit different.

 

[DuncB]

So @Horseflesh you are going to put an MFL to 8mm duotight fitting on the end of this?

I was only sending that link as an example of a connector option. I can bet that they are not made in NZ most likely China.
I have the female ended variant that I screw onto a gas ball lock post with 1/4 inch bulkhead. The manifold tube goes into the Duotight bit and the ball lock is outside the fridge. Then I just have the ball lock connector on the end of my cylinder so I can swap it easily or move it temporarily for other tasks.

 

[day_trippr]

fwiw, I have a number of gas manifolds and regulators and the threading of all of their valves is 1/4" npt...

Cheers!

 

[Horseflesh]

So @Horseflesh you are going to put an MFL to 8mm duotight fitting on the end of this?

That is the plan, yes.

I like your idea with the ball lock though. (In fact part of this project is going to be running gas lines through the side of the fridge so I can use a larger cylinder.)

fwiw, I have a number of gas manifolds and regulators and the threading of all of their valves is 1/4" npt...

Taprite confirmed that is the case, good support. I was sure it had to be 1/4" NPT, but every time I am "sure" about a detail like that I find out the hard way I should have double checked!

 

[tracer bullet]

I tried removing a barb from a tank valve and ended up simply breaking the whole valve - turns out it wans't a fitting after all. Agreed you might have that here as well.

Ended up with a basic flare --> barb fitting and it worked fine (on my new valve haha).

These are what I ran everywhere, actually, no actual Duotight fittings. Maybe not the easiest or best but they work fine (flare to barb fittings).

 

[odie]

why do you want EVA line on the gas side?

 

[Horseflesh]

Oxygen will diffuse into the gas side as well. Liquid lines are the primary benefit ... but since my manifold and QDs already have flare fittings (other than the manifold inlet) the cost to upgrade the gas lines isn't too bad.

 

[Holden Caulfield]

Another alternative if you don't want to / are unable to replace the barb. Not ideal, but reduces the amount of permeable gas line to less than an inch.

From a previous post...

The barb is part of the shutoff check valve as I was unable unscrew the barb from the check valve, so I jury rigged with picture below as a quick fix. Basically, it is the 3/8" barb to very short 5/16" gas line to 3/8" barb with 1/4" flare nut to 1/4" x 1/4" MFL connector (available at home depot) to duotight connector. It works fine but has a few more connections that could leak.

My future plan is to remove the entire check valve from regulator and replace it with one like this...

https://www.amazon.com/Taprite-Flare-Shut-Check-Valve/dp/B07GQ36CBS/ref=pd_lpo_79_t_2/130-7625199-3755317?_encoding=UTF8&pd_rd_i=B07GQ36CBS&pd_rd_r=3a2a9c5a-3102-4e21-adc0-2c5e9165a062&pd_rd_w=jwjP0&pd_rd_wg=bnIxk&pf_rd_p=7b36d496-f366-4631-94d3-61b87b52511b&pf_rd_r=FQBFXQZV6R9R4RX0KCZ5&psc=1&refRID=FQBFXQZV6R9R4RX0KCZ5

Probably can find a non-branded one cheaper. You can then attach a standard duotight flare connector to it. This will enable you to retain the shutoff check valve capability if important to you.

 

[DuncB]

I can see why that kegland Mk IV regulator with a Male that can take a flare or the duotight is a boon now. Theres a lot of joins there to leak.

I believe another way to do the across fridge wall connection is to use the kegland carbonation caps fitted to a longer shank that normally goes into the back of the tap on the outside and on the inside the standard connector for it that has a duotight on it. That method a bit more solid than mine as you can use the nuts to secure the shank on each side.

 

[Holden Caulfield]

I can see why that kegland Mk IV regulator with a Male that can take a flare or the duotight is a boon now. Theres a lot of joins there to leak.

^Yes, so I just did this after buying the parts a couple weeks ago. This thread inspired me to implement the solution and validate it will work.

All that is needed to use EVA on a 3/8" barb is to use 9.5mm/6.5mm EVA tubing and attach it directly to the barb by first softening in boiling water. See picture below. It just takes a little finessing - no swaging tool required. Not sure if the worm clamp is even necessary after everything cools.

Also, if you already are using 8mm EVA, which is what I have throughout my keezer, just attach a 4" length of 9.5 EVA (Morebeer sells in 10 ft lengths) then use a 9.5mm to 8mm connector, which you see in the picture. The black plug will be removed from the connector after testing the connection for leaks and 8mm tubing will be inserted. As you can see from the picture, everything is leak free at 40 psi.

 

[Horseflesh]

I like this idea better than unscrewing a shutoff valve that I know doesn't leak now. Maybe I can do the same on the manifold side...

 

[tracer bullet]

Barbed fittings and a few oetiker clamps.

Do you think you'll need to use the quick connect / disconnect feature often? If so, maybe duotights. Otherwise... you might be putting too much work into it.

 

[Horseflesh]

No, I don’t need QD but until I saw that post just above I wasn’t sure barbs would work. Now it looks like I can just use the bigger EVAbarrier from reg barb to manifold barb, which is great.

 

[tracer bullet]

FYI if it helps: Some tube, barb and clamp sizes

 

[Craiginthecorn]

Why not keep the existing hose to the manifold and change just the lines in your keezer with EVABarrier?

 

[tracer bullet]

Why not keep the existing hose to the manifold and change just the lines in your keezer with EVABarrier?

See post #13 above.

 

[ScrewyBrewer]

I just soaked the end of the EVA tubing and a small tapered punch in hot water and used the punch to stretch the diameter of the tubing until they fit over the barbed ends.

It provides a solid connection and eliminates the need of buying duotite fittings.

 

[tracer bullet]

Basically what I did too, but I added oetiker clamps.

There may be a few trials to get the process down, soaking the punch and the tube and maybe the fitting as well. Get a little compliance from the tubing, makes the job much easier.

 

[Craiginthecorn]

See post #13 above.

Yes, I understood that. My point is only that the line from your gas cylinder to the manifold need not be the same style as those used from the outlets to the kegs. Just trying to save you some time and effort.

I understand the desire to swap the gas lines to the kegs. The EVABarrier tubing is neater and more compact, but you also mentioned something about oxygen diffusing into the gas lines. I don't think that would really be possible given the positive pressure of CO2 inside the supply line. However, it is true the some CO2 can be lost through the walls of tubing, but that's why high quality gas tubing is either very thick-walled or laminated, so that the loss becomes insignificant.

I'm sure you'll find the best solution for your needs. Best of luck.

 

[tracer bullet]

The EVABarrier tubing is neater and more compact, but you also mentioned something about oxygen diffusing into the gas lines. I don't think that would really be possible given the positive pressure of CO2 inside the supply line. However, it is true the some CO2 can be lost through the walls of tubing, but that's why high quality gas tubing is either very thick-walled or laminated, so that the loss becomes insignificant.

We'd need a true expert to say 100% for sure, but I'm quite sure that even w/ the high pressure of the CO2, O2 can still come in.

I used to do some Helium leak test work, and would watch (well, sense with a meter) it flow upstream of a gas being blown out of a tube, and it work its way into high pressure areas that had any sort of leak to ambient - i.e. a crack in a weld. O2 isn't He, but gasses do indeed do non-intuitive things.

If good tubing and high pressure was enough, then we wouldn't need to change the beer lines either. Same pressures, same materials before the swaps.

 

[DuncB]

Gases obey the laws of physics so will always try and find equilibrium if given the chance.

 

[Craiginthecorn]

The industry's Draft Beer Quality Manual talks at length about oxygen and the importance of barrier tubing for liquid lines for protecting the beer from oxygen. There is absolutely no mention of using barrier tubing for the gas line.

 

[day_trippr]

Right. Then I would fault "The Industry" as being ignorant.

This isn't a shuttle launch, folks. Partial Pressure Gas Laws are a thing and the more tubing one has leading to beer that allows O2 to walk right through the front door the quicker a beer is going to literally die...

Meanwhile, one can throw in a couple of orders of magnitude of resistance for small money by using barrier tubing on both beer and gas sides...

Cheers!

 

[Craiginthecorn]

Yep. Dalton's Law is a bit of a mind-bender. I searched and searched, trying to find a single mention of oxygen ingress through CO² lines being a significant concern. This website was the only place I could find mention of it and it appeared that links to articles are replaced with asterisks by the forum software. My mention of a website on the paragraph below was similarly altered, so I edited it to no longer be a URL.

Even the LODO site, themodernbrewhouse dot com, makes no mention of it in their publicly-accessible content. They do emphasize, however, the importance of spunding due to the roughly 30ppm of O² in bottled, 99.9% food-grade gas. That makes sense to me, even if I'm not a subscriber to LODO methodologies.

Can someone share a link to a study which demonstrates the importance of using barrier tubing to prevent oxygen ingress into beer? If my gut instinct is incorrect and that I should be switching out my gas lines, I would genuinely love to know. I presently have a hunk of that really thick, stiff red tubing from the cylinder to the manifold, then much more flexible Bevlex laminated red tubing from the manifold to the kegs.

 

[tracer bullet]

Can someone share a link to a study which demonstrates the importance of using barrier tubing to prevent oxygen ingress into beer?

I looked a bit and didn't see it either. Started to spread the search to ingress of any gas through tubing from low to high pressure, but was at and am again at work without a ton of time. Genuinely interested as well.

I mentioned what I've seen w/ He leaks but will admit it could be apples / oranges. Other gasses may have to do.

Meters exist, if anyone owns one it wouldn't be a super difficult experiment. Drop one into an empty keg, hook up a CO2 line, and see what happens. Assuming the meter is good and doesn't drift, etc.

 

[Horseflesh]

I don't know how to calculate O2 ingress into a CO2 line and finished beer... college physics was a long time ago. But since I can apparently just use the 5 mm EVAbarrier tubing on the gas supply barbs that are already in place, and Duotight/4mm on the output barbs, there is no reason not to do it.

I will just have to live with whatever O2 comes in my CO2 cylinders. Having a pressurized CO2 source is too convenient to give up.

 

[Horseflesh]

I just soaked the end of the EVA tubing and a small tapered punch in hot water and used the punch to stretch the diameter of the tubing until they fit over the barbed ends.

I may as well give this a try first. Is that 5 mm EVAbarrier for the gas and 4 mm for liquid?

 

[day_trippr]

fwiw, I went with 4mm ID for beer and 5mm for gas...

Cheers!

 

[Horseflesh]

I think I have my shopping list together, thanks guys. I am going to try to keep the existing barbs and if I don't like how that goes I can always move to Duotight.

 

[tracer bullet]

If they are hard to slip onto the barbs, the earlier mentioned tips will be necessary. A tapered punch helps the lines get stretched a bit. Warm water is great too, not steaming hot but slightly uncomfortably warm. Dip the line, and also the punch and barb to maintain heat, and tinker until you get it stretched and assembled. Might take a few practice runs. Too soft and the line will crumple. It's do-able, but takes a bit of (quickly learned) skill.