shortening corny gas post tube

[Brewsta]

g'day all, i want to shorten my kegs gas tubes to increase kegged volume.

i know this is not a new subject & has been raised before, i have searched and read most of the threads but i'm not convinced on some of the answers against doing it.

From what i've read some people think this will damage the keg due to not enough head space. How can this be true when they are fitted with pressure relief valves?

I read a post by someone saying it's due to the post mix dispensing design and they're not intended for home brewing.

The only other reason i can think of why the gas tube is so long is to ensure air is driven out by placing the Co2 as close to the surface of the liquid as possible.

I can't see why shortening the tube to just above the maximum amount of beer you can fit & still get the lid on, that some people say is a no no..there would still be some head space albeit not the current inch and half or so they have now. But does it matter, i'm guessing there are others out there that have already done it without issues?

My current practice is to tilt the keg on it's side while racking until it pretty much fills up to the lid opening. After sealing the lid, i again tilt & purge C02 through the beer post whilst holding down the gas post poppet. i've never had any issues with infection so i am confident this method works. By doing this i manage to squeeze in almost another litre of precious amber fluid, but it's a little painful & would be much easier to cut off the gas tube.

after kegging today, i've pretty much made up my mind to cut them all off, unless you guy's can convince me otherwise?

 

[potof4x]

Never heard of or thought it. First thing I'm going to do when I get home but.

 

[potof4x]

I'm only guessing but I suppose that the headspace created by the longer gas in post allows an amount of gas to be coming out of the pressure relief if enough thermal expansion takes place, rather than liquid?

 

[razz]

Mate, I can't really see the point for a litre of beer but hey! they're your kegs, go for it. I haven't read the other threads you refer to. If you have excess beer when kegging then maybe bottle it and stick it away for another day.

 

[Bribie G]

I believe Florian posted about it and uses the method.
As long as you have a back flow prevention valve on your gas line it should be fine.

These cornies were never designed for beer and maybe the length of the gas dip tube was dictated by whatever the regular setup was in pubs and cafes that used them for syrup in post mix systems.

Find a old folks home and ask someone.

 

[CmdrRyekr]

Can't think you'd increase the volume by much... 1L perhaps? Tops.

You must hate the suggestion for lagering in these kegs, which is to shorten the main dip tube

 

[jibba02]

I dont see what the problem is? As long as you have a tiny bit of head space in the keg you can cover the dip tube as much as you like. Do you think the gas will stop flowing once it hits the liquid touching the dip tube?

 

[Brewsta]

yeah it's not quite a litre, maybe i'm just being a scab…but if theres room may as well fill it yeah?

thermal expansion, you might be right potof4x, in their original design use as a post mix keg, the syrup may have well been filled cold? and then transported & sat outside a pub for few days before use. Maybe syrup expands more than beer too dunno??? i still don't think it would stuff your keg though, it'd just be very sticky mess to clean up from the relief valve. [SIZE=14.2px]Mine go the other way around though, from brew temp conditioning (temp controlled) to cold <4 deg C, so it shouldn't be an issue yeah? [/SIZE]

I don't have a back flow prevention valve, but i'll look into one, a good fail safe, can't hurt i suppose, thanks.

and no issue of the gas tube in the beer it's already submerged & dispenses fine, there will be some headspace but not much.

 

[jibba02]

If you use a gas manifold, you my find it already has check valves.

 

[Danscraftbeer]

g'day all, i want to shorten my kegs gas tubes to increase kegged volume.

i know this is not a new subject & has been raised before, i have searched and read most of the threads but i'm not convinced on some of the answers against doing it.

From what i've read some people think this will damage the keg due to not enough head space. How can this be true when they are fitted with pressure relief valves?

I read a post by someone saying it's due to the post mix dispensing design and they're not intended for home brewing.

The only other reason i can think of why the gas tube is so long is to ensure air is driven out by placing the Co2 as close to the surface of the liquid as possible.

I can't see why shortening the tube to just above the maximum amount of beer you can fit & still get the lid on, that some people say is a no no..there would still be some head space albeit not the current inch and half or so they have now. But does it matter, i'm guessing there are others out there that have already done it without issues?

My current practice is to tilt the keg on it's side while racking until it pretty much fills up to the lid opening. After sealing the lid, i again tilt & purge C02 through the beer post whilst holding down the gas post poppet. i've never had any issues with infection so i am confident this method works. By doing this i manage to squeeze in almost another litre of precious amber fluid, but it's a little painful & would be much easier to cut off the gas tube.

after kegging today, i've pretty much made up my mind to cut them all off, unless you guy's can convince me otherwise?

Pretty much what I have done from the beginnings of my kegging experience. But fill the keg to ~10mm below the Gas tube. As to why I also shortened the gas pipe to as short as possible to minimize the head space and add the extra few glasses of beer.

 

[lael]

I'm pretty new to kegging. I didn't realise you weren't supposed to fill above the bottom of the gas in. Why is that?

Coincidentally, I was looking at how to replace the plastic dip tubes in some kegs I bought and came across a post that said the kegs were designed to be daisy chained with the syrup. Gas in the last keg and then the out to the in of the next keg etc. The dip tube was designed for that use. Although I'm unsure why that makes a difference...

 

[DJ_L3ThAL]

I'm pretty new to kegging. I didn't realise you weren't supposed to fill above the bottom of the gas in. Why is that?

Sprays beer out the PRV when you burp the headspace!

 

[lael]

Oohhh, that makes sense. So wouldn't that be an issue if you reduced the diptube too? How do you know where to fill to in the keg? (Can't see the gas dip tube)

 

[manticle]

I've filled many a keg to the top but I don't burp the headspace either. Dip tube is about 20mm long so I can't imagine how shortening it will do much.
I do some things topsy turvy but.

 

[Brewsta]

thanks everyone for your input.

20mm manticle??? mine would be approx 50mm inside the keg at a guess, i'll measure one as soon as i get a chance.

mine are pin locks, what are yours? is there a difference between pin & ball kegs i wonder?

 

[Coodgee]

I fill mine to the brim every time without modification of the keg. Sometimes a bit of foam sprays out of the pressure relief valve but i just hose it off. I don't keg on carpet!

 

[jibba02]

thanks everyone for your input.

20mm manticle??? mine would be approx 50mm inside the keg at a guess, i'll measure one as soon as i get a chance.

mine are pin locks, what are yours? is there a difference between pin & ball kegs i wonder?

Oh... mine are about 20mm or so

 

[Rocker1986]

At a guess I'd say the gas in diptubes in mine are about 20mm as well. These are the KK ball lock kegs, perhaps pin locks are longer. There are two weld lines on the inside near the top of the keg, I usually fill to somewhere between these two lines. It gives me about 19/19.5 litres or so. I'm happy with that. The excess gets bottled if there is enough to bother doing it.

 

[manticle]

thanks everyone for your input.

20mm manticle??? mine would be approx 50mm inside the keg at a guess, i'll measure one as soon as i get a chance.

mine are pin locks, what are yours? is there a difference between pin & ball kegs i wonder?

Ball locks.

 

[Brewsta]

mine are about 40-45 inside the keg at a guess, 50mm plus when removed. These are coca cola pin lock kegs made by spartanburg, i've tried uploading some photo's but not real clear...you can see why i want to shorten them yeah.





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