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Author Topic: Duotight disconnect doesn't connect?  (Read 519 times)

Offline Joe_Beer

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Duotight disconnect doesn't connect?
« on: October 29, 2022, 10:42:48 am »
Anyone ever have any problems with these Duotight disconnects: https://www.morebeer.com/products/duotight-flow-control-ball-lock-quick-disconnect-qd-beverage-8-mm.html?  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.

Offline erockrph

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Re: Duotight disconnect doesn't connect?
« Reply #1 on: October 29, 2022, 11:25:10 am »
I haven't used the Duotight QD's, but I have the original Duotight blowtie spunding valve and there is a slow leak in there somewhere. I haven't spent much time trying to troubleshoot, so there could certainly be user error involved, but I was always skeptical of their products after that. Note - this used a traditional "gray" gas QD with a flare fitting rather than a Duotight QD.

Is there anything different with the keg that works? Maybe these fittings have less tolerance for a poppet that doesn't seal perfectly. My first step would be to breakdown the "bad" kegs, check the posts and poppets for worn/nicked O-rings, misaligned poppets, etc. Then I'd slap some keg lube on all the o rings and try again.
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Online Bob357

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Re: Duotight disconnect doesn't connect?
« Reply #2 on: October 29, 2022, 12:23:22 pm »
"Seem to work" makes your description of the problem unclear. Have you tried all of the disconnects on the keg that works? Do they lock in place and not seal or do they not lock in place?
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Offline scrap iron

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Re: Duotight disconnect doesn't connect?
« Reply #3 on: October 30, 2022, 08:09:58 am »
I bought a few of these but the regular type not the flow control. They do seem to be tight on the kegs I have them on. I just put extra keg lube on the post O-ring and they go on a little easier. I just have to apply a little more pressure when pushing them on. The keg is a Cornelius type.

On a side note, how does that flow- control QD function do? 
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Offline Joe_Beer

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Re: Duotight disconnect doesn't connect?
« Reply #4 on: October 30, 2022, 08:56:42 am »
"Seem to work" makes your description of the problem unclear. Have you tried all of the disconnects on the keg that works? Do they lock in place and not seal or do they not lock in place?

Yeah the QDs fit a bit differently on each post. One  goes on "sort of normally" the other 3 posts - just too dang tight. All four kegs have the same brand of replacement posts on them which have always worked with other "standard" QDs.

They will lock in place if I push down super hard  while sliding the collar down with my fingers but trying to get it back off is nearly impossible. To figure out anything, I'll need to disconnect the kegs and pull them back out to do some measuring. I'm might be wrong but It feels like these new QDs may have been manufactured at the shortest post length within tolerance, and the ball lock posts manufactured to the longest length within tolerance. Seem like very little overlap for wiggle room.

I bought a few of these but the regular type not the flow control. They do seem to be tight on the kegs I have them on. I just put extra keg lube on the post O-ring and they go on a little easier. I just have to apply a little more pressure when pushing them on. The keg is a Cornelius type.

On a side note, how does that flow- control QD function do?

The flow control *does* work great to limit the flow but I wasn't able to determine if it actually does that without messing with the foam/head. I could get a pretty good pour out of my pilsner but I had to degass my IPA keg because it was spraying beer all over trying to get the QD on. It wasn't settled down enough to get a good pour yesterday.

Online Bob357

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Re: Duotight disconnect doesn't connect?
« Reply #5 on: October 30, 2022, 10:46:05 am »
If you haven't already, maybe some keg lube on the post O rings would help.
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Offline Joe_Beer

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Re: Duotight disconnect doesn't connect?
« Reply #6 on: October 31, 2022, 05:32:00 am »
Is there anything different with the keg that works? Maybe these fittings have less tolerance for a poppet that doesn't seal perfectly. My first step would be to breakdown the "bad" kegs, check the posts and poppets for worn/nicked O-rings, misaligned poppets, etc. Then I'd slap some keg lube on all the o rings and try again.

If you haven't already, maybe some keg lube on the post O rings would help.


Thanks. The lube helped a little but these things just don't fit my keg posts very well. Or the posts are just all very near, or out of, manufacturing tolerance. I have one of those stainless pop bottle carb caps I use for cleaning beer lines and the QD connects to that a lot easier. I tried measuring the distance with a caliper from the top of the post to the bottom of the angled shoulder and it's about .020" difference between the two (carb cap is shorter). Not an ideal way to measure that distance but all I got.

I emailed MoreBeer yesterday to see if they have gotten similar complaints about this or if my case is unique. I also ordered a new set of posts to see what they measure with the calipers. If they're shorter, I'll give them a try.

On a side note, how does that flow- control QD function do?

So 24 hours later, this tap still has a terrible pour. Even with the flow control wide open, or nearly shut. Yes it's controlling flow but slow-pouring a foamy beer, or fast-pour foamy beer, still isn't what I had in mind. I'm assuming this is due to the fit issue on the post somehow. The pilsner tap fits a little better and doesn't pour like this. All four lines are running the same pressure.


 


Offline goose

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Re: Duotight disconnect doesn't connect?
« Reply #7 on: October 31, 2022, 08:30:35 am »
Is there anything different with the keg that works? Maybe these fittings have less tolerance for a poppet that doesn't seal perfectly. My first step would be to breakdown the "bad" kegs, check the posts and poppets for worn/nicked O-rings, misaligned poppets, etc. Then I'd slap some keg lube on all the o rings and try again.

If you haven't already, maybe some keg lube on the post O rings would help.

Thanks. The lube helped a little but these things just don't fit my keg posts very well. Or the posts are just all very near, or out of, manufacturing tolerance. I have one of those stainless pop bottle carb caps I use for cleaning beer lines and the QD connects to that a lot easier. I tried measuring the distance with a caliper from the top of the post to the bottom of the angled shoulder and it's about .020" difference between the two (carb cap is shorter). Not an ideal way to measure that distance but all I got.

I emailed MoreBeer yesterday to see if they have gotten similar complaints about this or if my case is unique. I also ordered a new set of posts to see what they measure with the calipers. If they're shorter, I'll give them a try.

On a side note, how does that flow- control QD function do?

So 24 hours later, this tap still has a terrible pour. Even with the flow control wide open, or nearly shut. Yes it's controlling flow but slow-pouring a foamy beer, or fast-pour foamy beer, still isn't what I had in mind. I'm assuming this is due to the fit issue on the post somehow. The pilsner tap fits a little better and doesn't pour like this. All four lines are running the same pressure.


 


I sometimes have a problem with the beer-out disconnect not fitting well on the keg post and having to used a bit more force to get it seat on the keg plug.  I replaced the o-ring and that fixed the problem.  I am using a regular beer-out disconnects with the Duo-Tight fitting screwed on to the end of it.  I had once case where the fitting worked loose and started leaking around the connector.  Tightening it fixed the issue.

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Online Wilbur

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Re: Duotight disconnect doesn't connect?
« Reply #8 on: October 31, 2022, 03:51:47 pm »
I bought a few of these but the regular type not the flow control. They do seem to be tight on the kegs I have them on. I just put extra keg lube on the post O-ring and they go on a little easier. I just have to apply a little more pressure when pushing them on. The keg is a Cornelius type.

On a side note, how does that flow- control QD function do?

I've got 5 and they work great. They do seem to fit a bit tight on the posts.

I'm wondering if there's an issue downline from the QD. Doesn't matter if you're slowing the beer down if you have some beer stone or a clog in your faucet. I'd try swapping the pilsner faucet with the IPA QD or vice versa.


Offline Joe_Beer

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Re: Duotight disconnect doesn't connect?
« Reply #9 on: November 01, 2022, 07:34:57 am »
I replaced the o-ring and that fixed the problem.

Gave it a whirl but no improvement.  Good thought - thanks anyhow. :-\

I'm wondering if there's an issue downline from the QD. Doesn't matter if you're slowing the beer down if you have some beer stone or a clog in your faucet. I'd try swapping the pilsner faucet with the IPA QD or vice versa.

I could see the foam in the beer line from post to tap so my hunch is that it's something with the QD yet. I did try swapping out the QD with the pilsner one and it wouldn't go on any easier. I've got some new posts coming in the next couple days so going to do some measuring. I wish I had a lathe in my garage.

Offline Joe_Beer

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Re: Duotight disconnect doesn't connect?
« Reply #10 on: November 12, 2022, 06:27:09 pm »
SO... I got my new posts and the QD fits just as badly on them. After some noodling, I ended up taking one of the QDs apart and removing the center valve pin. The connector went on just fine. I tried a valve pin from a "regular" black QD and it fits in the Duotight QD OK, but still won't click on, without a lot of force, when put on the post.  So, something about the length of the valve pin isn't working with my posts. I 3d printed a mock-up of the valve pin so I could adjust some of the lengths accurately to test the fit. It appears that the length of the second diameter from the back of the pin needs to be .030"-.040" shorter to allow the QD to click onto the post easily. I don't know if there's flash from the production process that is interfering, or if my posts are just made to some other standard than what Kegland used for their QDs, but if I take about 1/32" off the length of that second diameter, things fit well. In the pic, the Duotight pin is the in the middle, and modified "regular" pin on the left. 3d printed pin is obvious.

I didn't want to modify the Duotight pin because I wanted to be able to send everything back if it didn't work out so I focused on modifying a "regular" black QD pin instead which, dimensionally, is quite close to the the Duotight pin (using calipers). So, I used my drill press and a piece of tool steel clamped to the table to cut the diameter back on a "regular" pin. Sketchy as hell, but worked.

The QDs click on easily now, and getting a good pour out of all faucets. Kinda blows my mind that I can have a beer line that is only 15" long and get a nice pour. Really glad these are working out now and hope nobody else has to go through this. If you are, and you come across this post, hope it helps.  Cheers.