Yet another mini-regulator thread

[agrazela]

I've been researching a portable regulator system for dispensing from a 2.5gal ball lock keg.

I've seen the super-mini keg charger systems that take the 16g CO2 cartridges; but the plastic-bodied trigger style sounds totally like junk, and even the metal-bodied ones with regulator get mixed reviews for reliability. And besides all that, it sounds like 16g cartridges would need to be changed out a few times to push even a 2.5gal keg, and I'd rather not have that hassle at a party.

I've seen mini-regulators that take 20oz or 32oz paintball tanks; but I think that's bigger than I want to lug to (and from!) a camping trip or beach party. I am still considering this possibility, though.

So then there is the middle range, the ones that take 45g, 63g or 74g CO2 cartridges with the 5/8-18 UNF thread. Something maybe like this one:
https://www.williamsbrewing.com/0-12-PSI-BALL-LOCK-KEG-MINI-REGULATOR-P4064.aspx

(That one's a bit more expensive than some others, but I very much like that it comes with a stainless ball lock that puts the cartridge perfectly vertical (might fit better in a cooler), has a built-in check valve, and I'm supposing that 0-12psi version will help me dial in serving pressure better than the 0-30psi version???)

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Here are my questions for those who have experience with this type of mini-regulator:

Are these reliable? Are they truly "set-and-forget" through the entire service of the keg?

Just how much CO2 does it really take to serve an already-carbed 2.5gal keg with one of these? In other words, would a 45g cartridge do the whole thing? Would I need a 63g or 74g to get through it?

And what if there is gas left in the cartridge after the keg kicks, I'd hate to waste it...if I simply remove the ball lock from the keg will it "hold" the remaining gas? Even for weeks?

Also, in a lot of online beer-stuff retailers' comments/reviews sections I see people leaving coments like, "this place is a rip-off at $12 for a 74g CO2 cartridge, I can get them at half this price all over the place."
Uh, like where?

Should I go this way, or should I just go paintball tank style? Just what are the dimensions of a paintball tank, anyway?
(Although with an adapter, it seems the 5/8-18 UNF mini-regs can use paintball tanks if I decide to go that way later...)

Thanks in advance for any insights.

 

[doug293cz]

It takes 68 grams of CO2 to push 5 gal of beer @ 12 psi.

Brew on

 

[agrazela]

It takes 68 grams of CO2 to push 5 gal of beer @ 12 psi.

Brew on

That is helpful, thanks. What's the math on that, does it depend on temperature?

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Is there anyone on this forum using this style of mini regulator?

 

[doug293cz]

That is helpful, thanks. What's the math on that, does it depend on temperature?

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Is there anyone on this forum using this style of mini regulator?

I'll post the math later when I have time. It does depend on temperature, and I did the calcs for 32˚F, cause I was too lazy to do the temp correction for other than STP. Higher temps will require slightly less CO2, but not a lot less.

Brew on

 

[doug293cz]

That is helpful, thanks. What's the math on that, does it depend on temperature?

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Is there anyone on this forum using this style of mini regulator?

Herewith, the math: CO2 (gas) at atmospheric pressure and 32˚F has a density of 1.9768 g/L, and there are 3.78541 L/gal. So, 5 gal of CO2 is:

5 gal * 3.78541 L/gal * 1.9768 g/L = 37.415 g of CO2​

But, that's at 1 atmosphere pressure, and if the keg is at 12 psig, then the CO2 absolute pressure is 12 psi + 14.695 psi = 26.965 psi. To correct for the serving pressure:

37.415 g * 26.965 psi / 14.965 psi = 67.958 g​

Now if the serving temp is higher than 32˚F, the CO gas density will be lower so we need to correct for that. Absolute zero is -459.67˚F, so the temperature correct is:

67.958 g * (32˚F + 459.67˚F) / (Serving_Temp[˚F] + 459.67)​

Thus to serve 5 gal at 40˚F, you need:

67.958 g * (32 + 459.67) / (40 + 459.67) = 67.958 g * 491.67 / 499.67 = 66.87 g​

So, not a huge difference as a function of temperature (about 1.1 g / 8˚F.)

Brew on

 

[Sammyseadog]

Hi,

I'm new to kegging and think I killed my first batch of dry-hopped IPA by transporting it in a keg from my mate's house (where I brew) to home

I had the brand new 2.6kg CO2 reg and tank at home, but after setting up and two days later it tastes like dead beer, not IPA. I think it oxygenated and I'm just wondering if a mini-regulator such as your discussing will allow me to purge my 19 litre cornelius keg with enough CO2 to allow transport to home? If so, would I just have to crack the mini-reg to 12 PSI and then purge the relief valve a few times? Would 16g bulbs be big enough for this or should I just go for 65 grams ones?
Be grateful for any info.
Sam

 

[doug293cz]

Hi,

I'm new to kegging and think I killed my first batch of dry-hopped IPA by transporting it in a keg from my mate's house (where I brew) to home

I had the brand new 2.6kg CO2 reg and tank at home, but after setting up and two days later it tastes like dead beer, not IPA. I think it oxygenated and I'm just wondering if a mini-regulator such as your discussing will allow me to purge my 19 litre cornelius keg with enough CO2 to allow transport to home? If so, would I just have to crack the mini-reg to 12 PSI and then purge the relief valve a few times? Would 16g bulbs be big enough for this or should I just go for 65 grams ones?
Be grateful for any info.
Sam

Sorry, you're gonna have to purge more than a "few" times to get the O2 content down to where you need it to keep an IPA fresh. Check out page 21 of: http://www.craftbrewersconference.com/wp-content/uploads/2015_presentations/F1540_Darron_Welch.pdf. You need to get O2 down below 0.15 ppm (150 ppb.) That takes 13 purge cycles at 30 psi. See the table and chart below.





A "full" 19 L (5 gal) keg has about 0.33 gal of headspace, and 30 psi gauge pressure is about 3 atmospheres absolute pressure, so each purge will take ~ 1 gal of CO2 at atmospheric pressure. So, 13 purges is going to use about 13 gal of CO2 @ 1 atm. Using the math from my previous post:

13 gal * 3.78541 L/gal * 1.9768 g/L = 97 g of CO2​

That's 97 g of CO2 to adequately purge a "full" keg. If the keg is not full, then it will take even more CO2 to purge it.

Brew on

 

[Sammyseadog]

Wow!!

That's an awfully detailed response. Thanks very much. So, I could purge all the CO2 with a couple of 65g bulbs but that'll cost about $20 so I'm just gonna be better to take my 2.6KG tank round with me and purge and pressurise it before taking her home. No worries. You've saved me time and money and, more importantly and hopefully, Beer!!

Cheers

 

[MerlinWerks]

Hi,

I'm new to kegging and think I killed my first batch of dry-hopped IPA by transporting it in a keg from my mate's house (where I brew) to home

I had the brand new 2.6kg CO2 reg and tank at home, but after setting up and two days later it tastes like dead beer, not IPA. I think it oxygenated and I'm just wondering if a mini-regulator such as your discussing will allow me to purge my 19 litre cornelius keg with enough CO2 to allow transport to home? If so, would I just have to crack the mini-reg to 12 PSI and then purge the relief valve a few times? Would 16g bulbs be big enough for this or should I just go for 65 grams ones?
Be grateful for any info.
Sam

Purging your keg to prevent oxidation is one thing and a worthy goal to pursue. But, in this particular instance if the beer wasn't already carbonated before you took it home, it's going to take a lot longer than two days to carbonate it, assuming you took it home and simply connected to your system at serving pressure. Give it at least another week or two, cold and under pressure.

If it was carbonated I can't see how it could have went flat by simply transporting it...

 

[Sammyseadog]

Hi Merlinwerks,

It has carbonated ok, it just tastes like metal. It may also have got an infection if I didn't sanitise the keg parts well enough, but oxygenation was my first guess as I transported it without CO2 and thought that would have "killed" it. I'll give it a few more days and taste again and try to do things differently next time. First, sanitise like crazy, second, purge with CO2 and hope it works out better next time.

 

[MerlinWerks]

In the past I have gotten what could be considered a metallic taste from over-carbonating. Look up "carbonic bite"

My understanding is that the main negative effects of oxidation (paper or cardboard taste) usually don't show up until some period of time has elapsed, like a month or more, although in the case of an IPA I suppose more delicate features such as hop aroma might be affected earlier.