Author Topic: Why are corny keg posts different? Why not switch them to all liquid posts?  (Read 1195 times)

Offline beerandloathing

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This may have been answered already, but I haven't been able to find a good answer...

I know that the corny keg posts are different, but I don't know why it was ever setup this way. Most kegs are labeled inlet and outlet so you can tell which post/disconnect belongs where, but I don't know why.

I recently inherited a new keg that has two liquid posts installed and caused some difficulty when I used it for the first time since I didn't realize it. Once I figured it out, I got to thinking. Why not convert all of my kegs to liquid only posts and never run into issues again? Is there any good reason not to do this besides having to buy new parts?

Offline duboman

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This may have been answered already, but I haven't been able to find a good answer...

I know that the corny keg posts are different, but I don't know why it was ever setup this way. Most kegs are labeled inlet and outlet so you can tell which post/disconnect belongs where, but I don't know why.

I recently inherited a new keg that has two liquid posts installed and caused some difficulty when I used it for the first time since I didn't realize it. Once I figured it out, I got to thinking. Why not convert all of my kegs to liquid only posts and never run into issues again? Is there any good reason not to do this besides having to buy new parts?

Primarily I think it's to avoid the possibility of inadvertently hooking the wrong QDs to the wrong posts even if they are labeled on the keg, just takes one easy error out of the equation. I know that I've tried to hook the wrong lines to the wrong posts on more than one occasion once the keg goes in the kegerator and the fact that the posts are different saved me from having a potential problem.
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Offline Stevie

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If you connect the gas line to a high pressure or recently jostled keg, you could foul your lines, regulator, and tank. For a homebrewer this may not be a huge deal, but for a restaurant using legs of pre-mix soda syrup, it could be a huge head ache.

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Offline Slowbrew

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I don't have any real information on this just experience with with large systems and support. 

Standards help avoid mistakes in fast moving environments so making the 2 posts different is an easy way to avoid errors out in the field.  At he homebrewer level it probably isn't important but on the scale these containers were designed for it likely solved some big issues along the way. 

One idea comes to mind might be in a commercial system.  Imagine a restaurant with 15 different sodas on the line that are stored in a room in the back.  The CO2 tank is outside in a cage.  You would need to manage up to 30 lines that may or may not have labels on them.  With identical ends you have no obvious way to identify inputs and outputs.  Maintenance would involve tracing lines (through walls, under fixtures, etc.) every time there was a problem.  At least if you can easily tell the difference between gas and soda you can save some time trouble shooting.

IMHO

Paul
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Offline reverseapachemaster

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I know that the corny keg posts are different, but I don't know why it was ever setup this way. Most kegs are labeled inlet and outlet so you can tell which post/disconnect belongs where, but I don't know why.

Of the four kegs I have I am 99.999% sure there are no labels on the kegs identifying which post is which and even if there were labels there is always the chance that after cleaning I accidentally reverse the tubes.
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Offline Frankenbrew

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The "in" posts for gas are notched and/or serrated around where you would fasten a wrench to tighten or loosen it.
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heart, you brew good ale.'

Offline narcout

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On some of my kegs, the liquid posts and gas posts are not the same thread size and so are not interchangeable.
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Offline Joe Sr.

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I know that the corny keg posts are different, but I don't know why it was ever setup this way. Most kegs are labeled inlet and outlet so you can tell which post/disconnect belongs where, but I don't know why.

Of the four kegs I have I am 99.999% sure there are no labels on the kegs identifying which post is which and even if there were labels there is always the chance that after cleaning I accidentally reverse the tubes.

Most of my kegs are scribed "in" on the gas side.  Not all.  Others have a bump or a divot on the rubber handle.  I assume the bump means "out" and the divot means "in" but I've not tested that theory since it just came to me as I was typing this.
It's all in the reflexes. - Jack Burton

Offline HoosierBrew

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Most of my kegs are scribed "in" on the gas side.  Not all.  Others have a bump or a divot on the rubber handle.  I assume the bump means "out" and the divot means "in" but I've not tested that theory since it just came to me as I was typing this.

+1.  Most of mine are scribed "IN" for gas, "OUT" for beer. Different threads for in and out, too.

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Offline euge

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Well I have managed to drunkenly force the gas QD onto the liquid-out post...

Filled my gas line partially up and it was a real b!tch to get back off again. >:(

Conversely, I've also connected the liquid QD onto the gas-in post and wondered why the beer wasn't just-a-flowin...
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Online JT

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Well I have managed to drunkenly force the gas QD onto the liquid-out post...

Filled my gas line partially up and it was a real b!tch to get back off again. >:(

Conversely, I've also connected the liquid QD onto the gas-in post and wondered why the beer wasn't just-a-flowin...
If you haven't done something similar to this while kegging, you're simply not enjoying your beer correctly.