Cutting Gas Dip Tube

[shadders]

So I'm rebuilding my brew rig after several years in storage. Just had to replace a reg due to the inevitable back flow accident (which occurred pre-storage). I've finally relented and bought a check valve but I'm now paranoid about the problem. I've also had cases where I've plugged in a pressurized/overfilled keg and ended up with beer all through my gas manifold and back into all my other kegs via the gas lines. Check valve isn't going to stop this unless I put one on every keg. I'm thinking I might pull out all the gas dip tubes and cut them really short so I've got a bit of extra headroom in the keg as a safety margin. Is there any reason not to? Is there any reason they are even there in the first place?

Also trying to figure out how to get a spare pressure gauge from the old reg connected to the gas line on the keg side of the check valve so I can still see keg pressure. Anyone know where I can get a fitting to attach a 1/4" NPT male to the gas line. I've got a 1/4" female socket with barb but it must have a different thread. I'm getting the feeling that NPT isn't that common in Australia?

 

[raven19]

Check valve isn't going to stop this unless I put one on every keg.

Incorrect.

One non return valve immediately after the regulator will mean no issues and no need to cut dip tubes.

Give your high pressured kegs a burp prior to plugging the gas in if you are concerned, but the above non return valve to solve any issues regarding to backflow.

 

[krusty_oz]

I'm not sure why the gas tube is the length it is, someone else may know the reason. The top of the dip tube needs to remain since the poppet rests on it. Having some headspace is important, too little means that the liquid has no where to expand when it warms up and it can cause the keg to rupture since it can't compress.

You can get a 1/4" NPT to 1/4" BSP adapter in the compressed air fitting section of your local 'green shed' or a hydraulic/fluid system (eg Enzed/Pirtek) place. NPT is common in high pressure fluid systems.

 

[jasonharley]

Two of my 19 L have gas tubes cut so they do not protrude from the post soffit.... the gas tube is less than a 1cm long....this is how I received them. I can tell that they don't affect operations as far as I am concerned.

If you are going to cut stainless tube ... make sure you cut it and give it 2-3 days to oxide the cut surface before you expose it to an acid environments such as beer.

cheers
5 eyes

 

[shadders]

Incorrect.

One non return valve immediately after the regulator will mean no issues and no need to cut dip tubes.

Give your high pressured kegs a burp prior to plugging the gas in if you are concerned, but the above non return valve to solve any issues regarding to backflow.

I'm not talking about it getting into the reg, I mean it won't stop it back flowing through the manifold that splits the gas line. If the manifold has 4 kegs connected, 3 at 70 kpa and one at 200 the gas is going out the 200 keg keg into the other 3.

I know all the safety procedures, vent the keg before plugging in, don't overfill the keg, turn off the valve to the reg until you've turned up the pressure etc... This is all for those slightly wobbly late night moments where rules get forgotten... I've been absolutely anal about those rules for years before but it only takes one moment of poor judgment. And alas we are in the business of manufacturing those moments.

 

[Thirsty Boy]

+1 for 5 Eyes' comment.

I cut a couple of my dip tubes short for this reason - aside from doing what I wanted it to, it has had no noticable effect on the performance of the kegs, to the point where I have actually forgotten which kegs have the short gas tubes and which dont.

 

[Bizier]

I love AHB, I was just thinking about this the other day, wondering why there needs to be a length of tube at all.

 

[jasonharley]

I love AHB, I was just thinking about this the other day, wondering why there needs to be a length of tube at all.

yeah ... so do i ...... maybe it was design to avoid filling kegs all the way to the top

5 eyes

 

[raven19]

I'm not talking about it getting into the reg, I mean it won't stop it back flowing through the manifold that splits the gas line. If the manifold has 4 kegs connected, 3 at 70 kpa and one at 200 the gas is going out the 200 keg keg into the other 3.

No worries I misinterpreted your OP.

...And alas we are in the business of manufacturing those moments.

Indeed we are!

 

[katzke]

yeah ... so do i ...... maybe it was design to avoid filling kegs all the way to the top

5 eyes

Got to remember these kegs were not made for dispensing home brew. They were made for soda pop. They way they are designed to work is to use more then one keg in a chain. The last keg on the chain is the one that gets replaced the most. The more soda that is expected to be sold, the more kegs that get hooked up.

So if you have 2 kegs, soda from the last one is pushed to the first one. That little dip tube keeps the free head space in the first keg when moving liquid from keg to keg.

That is why they are marked IN and OUT, not gas and beer.

 

[woodwormm]

Got to remember these kegs were not made for dispensing home brew. They were made for soda pop. They way they are designed to work is to use more then one keg in a chain. The last keg on the chain is the one that gets replaced the most. The more soda that is expected to be sold, the more kegs that get hooked up.

So if you have 2 kegs, soda from the last one is pushed to the first one. That little dip tube keeps the free head space in the first keg when moving liquid from keg to keg.

That is why they are marked IN and OUT, not gas and beer.

so if i want to run 2 kegs in series at an upcoming event (yes i am confident in the consistency of 2 of my kegs being the same)

how do i hook them up in series?

it may make it easier. ie set and forget, not have to do anything when a little 'happy'

 

[katzke]

so if i want to run 2 kegs in series at an upcoming event (yes i am confident in the consistency of 2 of my kegs being the same)

how do i hook them up in series?

it may make it easier. ie set and forget, not have to do anything when a little 'happy'

I am sorry, it is rocket science and if I tell you, well you know the story.

You hook keg 2 to keg one. Keg 2 “out” to keg 1 “in”. Gas gets hooked to the “in” of keg 2. Beer line gets hooked to the “out” of keg 1.

I have read people asking if it takes more gas. Think about it for a while. Why would it take more gas to push liquid out of one keg into a second keg and then empty the second keg? It would actually take less gas, as people will not continue to try and get beer out of an empty keg, twice. After that you are on your own.

Congratulations, you are now a rocket scientist.

This message will self-destruct in 3, 2, ….

Oh, and if you cut the “in” dip tube, you are on your own when your keg self-distructs!