Troubleshooting Leaking Duotight Flow Control QDs

[noahbanks]

I'm rebuilding a keezer that I purchased used because the chest freezer gave up the ghost and would have been more expensive to repair than to replace. I decided this was a good time to upgrade or change our a few components. Specifically, I decided to switch my beverage lines to EVABarrier, and, naturally, use some Duotight fittings.

Everything is working well so far, apart from one of my Duotight Flow Control QDs, listed here at MoreBeer: Duotight Flow Control Ball Lock Quick Disconnect (QD) Beverage Out - 8 mm | MoreBeer .

I am using two of these, and one seems to work without leaking and one is leaking from around where the tubing comes out the side of the QD. I cannot get the tubing to fully inserted into the QD. I love that the Duotight fittings have a "depth gauge" to show you how far you need to push it in, but I cannot for the life of me actually get the tubing in that far. One review on MoreBeet mentions this challenge too, and the reviewer used some pliers to get the tubing all the way in. I will try this when I get home, but I'm curious for any other tips or to know if anyone else has struggled with this.

Thanks!

 

[fluketamer]

i have had this problem with this part also. not with any other duotight fittings. i feel getting the tube in and out of this thing is a pain . i feel getting the tubing out is worse than inserting it. maybe keg lube would help but i havent tried it.

 

[sweets17]

I can't get them to filly seat either, even with keg lube. I thought I was doing something wrong...

 

[noahbanks]

I can't get them to filly seat either, even with keg lube. I thought I was doing something wrong...

This is a helpful reply, but disappointing to hear too. I will try the pliers tonight to see if I can get it to go all the way in. I will report back!

 

[DuncB]

I've seated mine ok but did have one that was leaking CO2 out through the top cap. Had to put an o ring in it.

I've been immersion testing all of mine now under pressure in case this occurs on another.

Agreed though much tighter to get the tube in and very hard to get out.

 

[noahbanks]

Even with pliers, I could not get a good enough grip or seat it completely. MoreBeer agreed to send me a new one, since the other one appears to be working OK. Maybe this one is really defective.

 

[odie]

depth gauge??? uh oh....I just shoved the line into the fitting until it wouldn't go anymore and thought it was "good".

exactly how far does the hoes need to go and how do you know?

 

[wsmith1625]

It's important to get a straigt cut on the tubing with push fittings. These were cheap and do a nice job.

https://www.lowes.com/pd/Kobalt-PVC-Pipe-Cutter/5003750421
I only use EVA barrier lines on the liquid side and have no leaks. I haven't found a need to convert my gas lines yet.

 

[noahbanks]

depth gauge??? uh oh....I just shoved the line into the fitting until it wouldn't go anymore and thought it was "good".

exactly how far does the hoes need to go and how do you know?

On the side of the disconnect there is a little arrow. I think there is a similar arrow on other Duotight products. It’s maybe about an inch of tubing. I understand that this was a change/addition to some of their products after some feedback about not knowing how much tubing to insert, so it might not be on all of them.

 

[noahbanks]

It's important to get a straigt cut on the tubing with push fittings. These were cheap and do a nice job.

https://www.lowes.com/pd/Kobalt-PVC-Pipe-Cutter/5003750421
I only use EVA barrier lines on the liquid side and have no leaks. I haven't found a need to convert my gas lines yet.

I have this from MoreBeer, and it works great for getting a nice, clean cut! Bit of a unitasker but handy!

https://www.morebeer.com/products/tube-cutter-2-1-duotight-removal-tool.html

 

[BongoYodeler]

depth gauge??? uh oh....I just shoved the line into the fitting until it wouldn't go anymore and thought it was "good".

exactly how far does the hoes need to go and how do you know?

Same here.

 

[wsmith1625]

I have this from MoreBeer, and it works great for getting a nice, clean cut! Bit of a unitasker but handy!

https://www.morebeer.com/products/tube-cutter-2-1-duotight-removal-tool.html

What size tubing are you using?

 

[noahbanks]

What size tubing are you using?

8mm OD / 5mm ID EVABarrier.

 

[Broken Crow]

One of the problems I've encountered with duotight fittings is this: You know how sometimes when you use a tube-cutter you end up either cutting at a very slight non-90° angle or there is a very miniscule tab left on part?
Try cutting a bit more off the end of the tubing and be certain it is a perfectly 90° clean cut. Sounds lame, but it worked for me.

 

[noahbanks]

One of the problems I've encountered with duotight fittings is this: You know how sometimes when you use a tube-cutter you end up either cutting at a very slight non-90° angle or there is a very miniscule tab left on part?
Try cutting a bit more off the end of the tubing and be certain it is a perfectly 90° clean cut. Sounds lame, but it worked for me.

I will double check that when I get the new QD tomorrow and make sure that that is set up for success. I do think that the cuts were good, but I will make a fresh one and make sure that it is perfect.

 

[DuncB]

I put a pen mark on the tube corresponding to the depth from the entry point of the fitting and the depth line or the equivalent point.

 

[SanPancho]

You’re supposed to push t in as far as it goes, then pull it back out a bit. That sets the second seal. From morebeer product director.

 

[noahbanks]

I put a pen mark on the tube corresponding to the depth from the entry point of the fitting and the depth line or the equivalent point.

Yes, I did this too! That was how I could tell it was not seating all of the way. Thanks for sharing that tip.

 

[noahbanks]

You’re supposed to push t in as far as it goes, then pull it back out a bit. That sets the second seal. From morebeer product director.

Yeah, I think that’s what engages the metal teeth the dig into the tubing. Great tip!

 

[SanPancho]

Yeah, I think that’s what engages the metal teeth the dig into the tubing. Great tip!

It also leaves perfect amount of space to put in plastic retainer/locking clip, make sure tubing can’t pop out accidentally.

 

[noahbanks]

Update: I was able to seat the tubing into the new QD once. I had to remove it to troubleshoot an issue with my keg leaking… and now I can’t get it in again. I think my solution will either be to get the regular, non-flow control Duotight QD or get the 1/4” flare to Duotight and just reuse my regular QDs.

 

[sweets17]

Update: I was able to seat the tubing into the new QD once. I had to remove it to troubleshoot an issue with my keg leaking… and now I can’t get it in again. I think my solution will either be to get the regular, non-flow control Duotight QD or get the 1/4” flare to Duotight and just reuse my regular QDs.

I'm about to pick up something like this or even sand the outer diameter down.

 

[wepeeler]

I've been meaning to try these out so I can shorten my liquid lines, but I'm not crazy about all the bad reviews.

I use evabarrier tubing and duotights on every else liquid side and even for pressure transferring. If this product actually worked properly I'd buy them for every keg!

 

[sweets17]

I've been meaning to try these out so I can shorten my liquid lines, but I'm not crazy about all the bad reviews.

I use evabarrier tubing and duotights on every else liquid side and even for pressure transferring. If this product actually worked properly I'd buy them for every keg!

I should say the one I have installed works and works great. I have not noticed any leaking. It's just not fully seating to the proper depth.

 

[DuncB]

Maybe stand tube end in ice cold water or freezer and shove it into warm duotight?

 

[noahbanks]

Maybe stand tube end in ice cold water or freezer and shove it into warm duotight?

I am definitely going to try this when I get home. I just realized, thanks to you, that the last time that it worked, the line had been kept in my keezer while the fitting was room temp... Very interesting! I will report back.

 

[noahbanks]

I am definitely going to try this when I get home. I just realized, thanks to you, that the last time that it worked, the line had been kept in my keezer while the fitting was room temp... Very interesting! I will report back.

This did not resolve my problem.

I did sacrificially disassemble one of the QDs that’s giving me trouble. I noticed that one of the o-rings in the spot where you insert the line was set up at a roughly 45° angle relative to the opening. It was the translucent one farther in. I wonder if this is normal or if perhaps this is what is causing this issue. Can anyone else check their Duotight flow control QD?

 

[noahbanks]

I was able to see that o-ring from the outside without any disassembly, just to be clear. The disassembly was me trying to get it seated fully/parallel to the opening to insert the line.

 

[IslandLizard]

I noticed that one of the o-rings in the spot where you insert the line was set up at a roughly 45° angle relative to the opening.

I wonder if a little bit of lubrication (keg lube) on the end of the tubing can help with insertion, and retraction later, preventing the tubing from sticking to the o-rings, potentially even de-seating them, as what you just described.

It's puzzling how that o-ring "flopped" out of it's channel. It's a very tight space, there's not much room for it to move.
Is the end of the tubing, where it was cut off, smooth? Or can there be a little burr left on the end? That could be the cause of flipping up the o-ring when retracting.

Those QDs are not a cheap commodity. And when the Duotight connection fails the whole QD becomes useless.

I would take this issue up with @KegLand.

 

[DuncB]

Agreed Kegland for advice, however their standard reply is we can't help nothing to do with us when supplied outside of Australia.
Tend to also say never heard of this problem you're the lucky first.
But I had a needle valve with a push fit connection that leaked and when I looked in the hole I could see O ring in an odd position. Non Kegland.
This was something I managed to take apart ( with some difficulty) and the oring was damaged as well or as consequence of misplacement.I reseated or properly seated for first time the new oring and it's worked fine since.

 

[seatazzz]

I have duotights and evabarrier on both the gas and liquid sides of my kegerator, and also on my 5lb co2 tank. Probably was noted above, but when seating the tubing go slooooooow, and twist it a little bit until it pops in. Another small trick I use is holding back the little dohickey that you push in to release the tubing, while inserting it (I fortunatley have small fingers). It does sound like the one that won't seat could be defective.

 

[sweets17]

The only way I can get them to fully seat is by applying keg lube with a cotton swab on both inner rings, cutting the tubing at a slight angle, applying lube to the tube and brute strength. Seems to work.

 

[IslandLizard]

Another thought... After cutting the tubing is it possible the end is not perfectly round anymore, causing some of the bad fitting issues?
IMO, there's no way to cut it without compressing it somewhat.

BTW, I haven't switched to the EVA tubing, yet, but will in the near future (been saying that for over a year already).

 

[beren]

It also leaves perfect amount of space to put in plastic retainer/locking clip, make sure tubing can’t pop out accidentally.

Is this a problem? I can’t easily get the tubing out even with a tool lol.

 

[noahbanks]

I when to my LHBS and picked up a 1/4” flare to 8mm Duotight fitting. I used one of my regular ball lock QDs and I was able to get the keg set up really quickly and easily, leak-free. I think Duotight is super cool and that the flow control QD is just not very good. I think it’s an o-ring issue.

MoreBeer is sending me one more replacement flow control QD to try out. I will check the o-rings on that new one to see what they look like before I try inserting any line.

 

[SanPancho]

Is this a problem? I can’t easily get the tubing out even with a tool lol.

It doesn’t happen alot, but when it does it’s pretty disastrous, at least on the liquid side. Clips are cheap insurance.

 

[Yesfan]

I have duotights and evabarrier on both the gas and liquid sides of my kegerator, and also on my 5lb co2 tank. Probably was noted above, but when seating the tubing go slooooooow, and twist it a little bit until it pops in. Another small trick I use is holding back the little dohickey that you push in to release the tubing, while inserting it (I fortunatley have small fingers). It does sound like the one that won't seat could be defective.

Agreed. I have the same FC QD and had the same issue with the tubing not going in all the way. A slight twist with continual pushing and you feel it pop in place. The other fittings aren't this way and go in a lot easier.

 

[odie]

well...swapped some kegs this weekend and changed out another 10ft line to a shortly with flow control...

yep, looking at the flow control QD there is indeed a mark for fully seated...and all of mine were not fully seated. but were not leaking either.

The only way I could get the lines to fully seat was to use keg lube and even then, I still had to use lots of force to get it past the second o-ring.

very frustrating to say the least...

 

[IslandLizard]

I bought four of them but they only seem to fit one of my kegs. The balls don't seem to be "locking" when you push down on it so it's just leaking beer all over. Not sure if there's an adjustment or something? I've never had a problem with the standard beverage "black" discos on any of the keg posts so this is kindof a new problem.

Are you pushing them down far enough?

Are you pulling the collar up before pushing them on, then releasing it once the QD is down on the post?
Be sure hear or feel the click when it engages.

What brand are they? Chinese manufacture can be very much hit & miss, often due to crappy manufacturing and lack of QC.
I only get CMB brand QDs, the name is stamped around the top flange.

 

[Deadalus]

Another minor adjustment to consider when inserting is that besides the occasional off-90 degree face cut on the end of the tubing, the tubing itself generally curves along the length of the piece due to being rolled up when stored. Sometimes spinning the tubing or the fitting uncatches the tubing and gets it fully inserted. To me it feels like sometimes the tubing catches on an o-ring and the force is downward some due to the curvature of the tubing.

@xuledywo you are talking about a Duotight FC QD correct? Raise the ring like @IslandLizard mentions with one hand and and give a firm push even gentle strike with the fleshy part of your palm straight down on the screwtop. The tolerance on these is likely tight to begin with as I have found that to be the case for the regular Duotight QDs. I have like 8 of those and several have been tough to get on. I got frustrated because they are smaller, lower profile and hard to push straight down so I smacked it last time I was connecting and it clicked right on. I am hoping over time they will loosen up some.