Duotight Flow Stopper Automatic Keg Filler

Duotight Flow Stopper Automatic Keg Filler

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The Duotight Flow Stopper is a handy devicie to use while filling kegs or when transferring between kegs during filtering or after fining. Simply attach the Flow Stopper to the gas post of your keg, then when the keg is full it will automatically cut off flow and prevent excess beer from exiting your gas post and spilling onto the floor.
For even better results, we recommend using the Flow Stopper with the BlowTie Spunding Valve. The BlowTie will enable you to apply head pressure to the keg, meaning you can control the flow speed and reduce the foam generated in the filling process. You will need a short length of 8 mm OD EVABarrier tubing to connect the BlowTie to the outlet of the Flow Stopper.
  • 2 x Duotight 8 mm x 5/8" FPT (DUO104)
  • 1 x Duotight 8 mm elbow (DUO107)
  • 1 x Duotight 8 mm x 1/4 in. flare (DUO106)
  • 1 x Ball float
  • 1 x Stainless spring
  • 2 x 8 mm OD EVABarrier joiners
  • 1 x Acrylic sight glass
Ball lock fitting and BlowTie spunding valve not included.
Kegland Part number: KL09393
Item # DUO250
Shipping Eligible for Free Shipping Program
Availability California - In Stock
Pennsylvania - In Stock
Weight 0.12 LBS
Community Q&A

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Added for Overfill protection for Keg to Keg Transfers
David Lange on Feb 20, 2023
Keg to keg transfer.
Randy Francis on Dec 15, 2022
Added for Overfill protection for Keg to Keg Transfers
David Lange on Feb 20, 2023
To help when filling my kegs
Matt C on Jan 5, 2023
Keg to keg transfer.
Randy Francis on Dec 15, 2022
To prevent overflow when doing a closed transfer
Steven Johnson on Nov 18, 2022
Blew beer into spunding valve last time
Thomas Parshall on Sep 28, 2022
Makes Filling Kegs Autonomous
Hunter H on Sep 19, 2022
Protect my equipment.
Jay T on Jul 21, 2022
Prevent liquid from entering spunding valve
William Bickerton on Jul 12, 2022
With a new toddler in the house, my last two batches overflowed the keg. I'm hoping this will allow me the grace to be distracted while filling kegs.
Will C on May 27, 2022
interested in keg filling with exposing air
Jon M on Mar 25, 2022
This will make closed transfer to keg much easier
Stanley J on Mar 7, 2022
Automatic stop when filling keg
William Carter on Jan 31, 2022
I wanted to not overfill my kegs
Robert P on Jan 22, 2022
Help with pressure transfer while kegging
Peter Place on Jan 22, 2022
Simplify racking to keg from fermzilla
Peter Dietz on Dec 2, 2021
Set up closed transfer to mini keg growler
Cody E S on Dec 2, 2021
for purging kegs and easy filling of kegs from conical without scale
John H on Oct 12, 2021
Less anxiety when doing transfers
Ted on Oct 8, 2021
Stop mucking up my spunding valve when I transfer to keg
Mark P on Sep 14, 2021
stepping up my kegging game. Adding to spending valve for pressurized filling/transfer.
Ju S on Sep 13, 2021
so i can see when its getting close to when my keg is full
curtis g on Sep 1, 2021
Keep beer from getting to the pressure gauge while transferring under pressure from fermenter
Kurt H on Aug 28, 2021
Filling mini kegs
Justin B on Jul 15, 2021
keg to keg transfers
Joseph G on Jun 17, 2021
For close transferring into my kegs
Randall K on Jun 2, 2021
Time saver
Tracey H on May 25, 2021
Keg filling
Kenny Lyons on Mar 30, 2021
need for ease to stop over spill of kegs
Gary on Mar 25, 2021
I recently started transferring pressurized beer to kegs. Thought I'd give it a try.
mark a on Feb 16, 2021
So I don’t have to watch kegs so closely as they fill
Will S on Jan 13, 2021
Easy transfer from Primary to Keg
Miguel Corrales A on Dec 9, 2020
Saw this on your site. I want a contained method to transfer from fermenter to keg.
Richard W on Nov 11, 2020
dont want to over fill
wes m on Oct 1, 2020
for easy closed transfer kegging
Michael Clark on Sep 24, 2020
I overfilled my last keg doing closed transfer. Hope this will keep that from happening again.
William S on Sep 4, 2020
closed transfer
steve geer on Aug 24, 2020
make tranferring from fermenter to keg more seamless
Kim Z on Aug 12, 2020
To fill up kegs
Wenceslao Q on Jul 21, 2020
Gift for friend. Great accessory for filling kegs (when used with pressure regulator
Mike F on Jul 13, 2020
To assure kegs properly filled.
Allen H on Jun 27, 2020
Nervous about pressure transfers
Ken M on Jun 18, 2020
To not overfill keg
Joseph M on Jun 10, 2020
Want to try this
Thomas J P on Jun 8, 2020
I'm filling keg-to-keg. This will be useful for that. ;-)
Matthew S on Jun 6, 2020
To transfer beer from larger kegs to smaller kegs while keeping the beer in an oxygen-free environment.
Tim B on May 19, 2020
Want to get into bigger batches and fill a keg under pressure with spending valve without getting overflow beer in valve
Michael A on May 16, 2020
To make pressure transfers easier
Justin B C on Apr 4, 2020
Reduce spillage and know when keg was full
Stephan E on Mar 21, 2020
Pressurized closed transfers.
Kyle Heon on Mar 13, 2020
Makes filling kegs easy, no more overflows!
The_Bishop on Mar 5, 2020
To help when filling my kegs
Matt C on Jan 5, 2023
To prevent overflow when doing a closed transfer
Steven Johnson on Nov 18, 2022
When transferring uncarbonated beer to a keg, will this stop flow before the gas tube is submerged?
Jacob Bryant Fleener on Jan 15, 2020
BEST ANSWER: No...not at the exact moment it reaches the bottom of the gas tube But shortly after when it rises up into the flow stopper a.k.a. (a check valve) and causes the ball to rise and shutting off the flow to the keg. * you will have about 1 inch of head space left in your keg left.

take care
Will foam trigger flow stoppage, thus preventing a spunding valve from getting soiled? How vertical does this need to be to function?
Colin Kelemen on Feb 6, 2020
BEST ANSWER: Colin - This should actually be placed on the gas in side, before a spunding valve. We do recommend FE690 to throttle filling, but this can be placed after the flow stopper.
Duotight BlowTie | Diaphragm Spunding Valve | 0-40 PSI | 8 mm Duotight
Duotight BlowTie | Diaphragm Spunding Valve | 0-40 PSI | 8 mm Duotight
Can this be used if you have a checked gas disconnect?
Antonio Martinez on Apr 22, 2020
BEST ANSWER: No. The checked valve flows only into the keg. You will need to use an unchecked QD for this device.
Does this need to be used with a ball lock gas fitting that comes off the keg at a 90 degree angle like the stainless torpedo fittings do? I have the plastic ones that come off the keg at 45 and i worry that angle might keep it from functioning.
Clifton Lawson on Mar 19, 2023
BEST ANSWER: I just bought the duotight bev fitting and one of the solid straight fittings. It's a few more bucks for peace of mind. I've found you still have to keep an eye on things as the ball doesn't always float well to seal things off.
Are there any detailed assembly instructions?
Ben Wells on Nov 25, 2020
BEST ANSWER: If you look at the pieces and the picture, you've already figured it out. It's that easy.
Can you use this with a sanke keg with the proper fittings?
Kenneth Graley on Oct 31, 2019
BEST ANSWER: Maybe, you would need the Sanke adapter (https://www.morebeer.com/products/sanke-flare-adapter-14-male.html) but you might to need to change out some of the tubing/connectors to get the proper angle.

4.8 / 5.0
16 Reviews
5 Stars
4 Stars
3 Stars
2 Stars
1 Star
Rated 2 out of 5
Sight glass Duotight connections are dubious
I've had good experience with Duotight connections before but this component would not let me remove the 8 mm rigid joiner even with the Duotight tool. I wound up breaking the top sight glass connection and now it is largely useless.
February 4, 2024
Rated 5 out of 5
Nice Addition
I added this to my Spunding Valve assembly as I primarily use it for keg to keg or fermenter to keg transfers. Very nice assembly.
February 27, 2023
1 year ago
Rated 5 out of 5
Duotight Flow Stopper Automatic Keg Filler
2 kegs and it seems to work. I still keep a close eye on the process but haven't had any problems.
December 28, 2022
1 year ago
Rated 5 out of 5
Walk away
Great product added spunding when in use.
scale and babysitting not needed. Great.
November 18, 2022
1 year ago
Rated 5 out of 5
Go With the Flow (Stopper)
Haven’t stepped up totally to kegging, but now packaging in 2.5 litter growlers for my 10 liter batches Flow stopper makes it easy peasy.
July 7, 2022
over 2 years ago
Rated 5 out of 5
Avoid oxygen pickup when transferring to a keg
Another tool to reduce O2 pick up especially for hoppy beers. I can CO2 purge my keg and preform a closed transfer using this device to auto shut off when the keg is full. Especially helpful filling multiple kegs. Allows you to clean up and not have to worry about overfilling while multitasking.
May 24, 2022
over 2 years ago
Rated 5 out of 5
awsome tool
I transfred 15 gallons from one keg to another it worked great i have it hooked up to a blowtie spunding valve and they both worked great!!!!!!!
September 14, 2021
over 2 years ago
Rated 5 out of 5
Great tool for kegging
This thing is great if you’re like me and make a little over 5 gallons. I pressure transfer into kegs. Now I don’t even need to hang around to babysit the filling.
May 11, 2021
over 3 years ago
Rated 4 out of 5
Works great with one caveat
This has allowed me to walk away from my closed transfers without worrying about making a mess or gumming up my spunding valve.

I did have one instance of the ball getting stuck and not seating properly - I now give the tube a quick spray of star san first and haven't had an issue.
April 21, 2021
over 3 years ago
Rated 5 out of 5
stop beer spill
This device saves the day when filling kegs Must buy and try you won't be sorry
April 15, 2021
over 3 years ago