Beer engine + check valve + KeyKeg

[RyanInTW]

Hi all

I stumbled onto these forums looking for any and all information regarding getting beer from a KeyKeg Slimline flowing through a beer engine (Angram CQ) via a check valve.

There are a couple of handy posts I read here and here on the forums, but I'm struggling on the check valve element.

At first my instinct was to use the valve to allow flow towards the engine only, to prevent any air and beer exposed to air flowing back into the keg. The result was beer flowing out of the pump like a faucet.

Then I thought to myself that would obviously happen due to valve running in that direction - so I reversed the valve thinking that the pump would force open the valve and allow beer to flow when the handle is pulled. But this seems to defy the point of a one way valve, and I seemingly can't get any flow out of the pump this way - perhaps I'm not using enough pressure? 2-3 PSI was enough to get it spouting the first time around.

To give the details on the setup, a fridge holding the KeyKeg Slimline sits directly below the pump. There is approx 70cm of line inside the fridge before reaching the check valve. The check valve bridges the inside of the fridge to outside, at which point there is another 15cm of line from the valve to the CQ pump.

Does anyone have any pointers...?

 

[peebee]

Just for convenience, someone decided to call them "check valves". They are NOT! It is more accurate to call them "demand valves", so forget thinking of them as check valves especially if you've done any plumbing.

You've got links to my description of such things in one of the above links you've posted. It confused me when I first started out, but I managed to get a real check valve to work based on its "cracking pressure" being enough to hold back the miniscule pressure I was using.



(EDIT: I initially answered this as if you were trying to use a beer engine "check valve" as a real check valve. Seems not, rereading your post suggests you ARE using a real check valve. Throw it away and get a demand valve like the one in "Bigjas's" post that follows).

 

[Bigjas]

I use this demand Valve in my set up http://cfbsonline.co.uk/index.php/check-valve-demand-valve-with-3-8-jg-in-1-2-barbed-out.html

I use a king keg - Demand Valve - Angram pump. Set the pressure to approx. 3 - 5 psi in the keg and it works well.

 

[RyanInTW]

And the cloud of confusion is lifted!

Thank you so much for explaining peebee where I was going wrong, and thank you Bigjas for the link to an appropriate Check+Demand valve! Reading the product description as well also clarifies even further, which is great.

Now I just have to get one of these pieces shipped out to Taiwan!

 

[RyanInTW]

Can I follow that up with another question just to further clarify?

The Check+Demand valve that Bigjas mentioned states it can operate up to 45 PSI. This would seem to imply the demand valve is adjustable? In which case I would need to determine a correct balance between the keg pressure and the amount of pressure the engine can exert?

3-5PSI on the CO2 seems about right, but does anyone have any idea what sort of pressure an Angram CQ 1/4 Pint would exert on the line?

For arguments sake, if the keg and pump are both 5PSI, then setting the Check+Demand valve to around 7-8 PSI would (I presume) be sufficient to exert enough pressure on the valve to flow when pulled, and hold the beer back when not?

 

[Bigjas]

I'm not an expert on these setups, but I don't think the demand valve is adjustable. I believe the way it works is it will hold a pressure up to 45 psi on the keg side of the valve. As you use the hand pump, it creates a vacuum on the delivery side of the valve and opens. I don't think you need to do any balancing. In my setup, I have had the keg pressure at anywhere between 10 and 1 psi and it still worked ok.

 

[peebee]

Can I follow that up with another question just to further clarify?

The Check+Demand valve that Bigjas mentioned states it can operate up to 45 PSI. This would seem to imply the demand valve is adjustable? In which case I would need to determine a correct balance between the keg pressure and the amount of pressure the engine can exert?

3-5PSI on the CO2 seems about right, but does anyone have any idea what sort of pressure an Angram CQ 1/4 Pint would exert on the line?

For arguments sake, if the keg and pump are both 5PSI, then setting the Check+Demand valve to around 7-8 PSI would (I presume) be sufficient to exert enough pressure on the valve to flow when pulled, and hold the beer back when not?

No they are not adjustable, just rated for how much pressure they can take before possibly failing. I've got two of those 45PSI demand valves and one only rated at 5PSI.

Can't really understand the 45PSI jobs, they cause spectacular fobbing even at 5PSI. And why would anyone attempt to serve hand-pulled ale at those pressures anyway? Their true purpose is to prevent gravity causing beer to flow out of the pump if the cask is higher than pump. Or slight pressure build ups when the cask is hard spiled for the night after serving. We can use the feature to apply small pressures to our home-brew to keep it in condition for more than 2-3 days: You use 3-5PSI, I advocate 50-150mbar LPG regulators to maintain 1-2PSI.

I do not advocate "breathers" or 37mbar LPG regulators because they will not hold onto condition after 5-6 days (perhaps 14 days in the case of 37mbar LPG regulators). I also do not advocate above 2.5PSI (sorry!) because even such low pressures start interfering with subtle flavours in beer.

 

[RyanInTW]

I advocate 50-150mbar LPG regulators to maintain 1-2PSI.

Great great feedback thank you!

I never even considered that it would be possible to use an LPG regulator on a CO2 canister. Having gone back to our valve supplier (here in Taiwan) he advises the check valve we are currently using is also a demand valve, with a limit of 5PSI.

Presumably if I do as you suggest and drop to 1-2PSI the problem would be solved? Can I just switch my current regulator with a 50-150mbar LPG regulator? Any special connection setup I need to consider?

 

[peebee]

Great great feedback thank you!

I never even considered that it would be possible to use an LPG regulator on a CO2 canister. Having gone back to our valve supplier (here in Taiwan) he advises the check valve we are currently using is also a demand valve, with a limit of 5PSI.

Presumably if I do as you suggest and drop to 1-2PSI the problem would be solved? Can I just switch my current regulator with a 50-150mbar LPG regulator? Any special connection setup I need to consider?

NO! Please don't use a LPG regulator on a CO2 cylinder. Use the LPG regulator as a secondary regulator downstream of the primary regulator which has dropped the pressure to manageable levels. My regulators can handle 10BAR, my primary regulator puts out half that (5BAR).

I did a primer here : http://www.thehomebrewforum.co.uk/showthread.php?t=67424

You can also download that document of mine covered above (its on my "Google drive" so there are no payments for it or adverts). Quick link: https://drive.google.com/open?id=0BwzEv5tRM-5EQUhZbDNPdmV1bWc

 

[peebee]

I've just remembered, you're using KeyKegs (Bag-in-box setups). The pressure isn't so important as long as it's enough to retain sufficient dissolved CO2 in the beer (1-2PSI). And it doesn't have to be CO2 to apply that pressure (a bike pump is a method I've heard of). If the pressure is 10PSI of CO2 it can't dissolve into the beer because the bag forms a barrier. The problem you'll have is ensuring the beer only has about 1.1 volumes of CO2 dissolved in it when coming to serve (if you are emulating cask-conditioned beer), but if you are using a LPG regulator the beer should give up excess CO2 after a few pints. How you would otherwise "vent" excess dissolved CO2 I've no idea because I've never used KeyKeg.

 

[peebee]

I can't let my lack of experience with KeyKegs sully my posts, so here's something I picked up on venting KeyKegs by a guy I know in the Lake District.

http://hardknott.blogspot.co.uk/2012/08/keykeg-dispense.html

Seems straight forward enough and could easily be adapted to the methods I describe in my document. Be warned: Dave is demonstrating venting for Pub dispense and venting off all pressure and doing it rather quickly for my liking. I'd retain 1-2PSI of pressure (this is in the inner bag of the KeyKeg) on homebrew to maintain condition for however long it is being kept.

 

[RyanInTW]

Hi again Peebee! Great feedback again thanks!

I'm familiar with Dave's video, it was one of my early reference points, and he's been most helpful over FB as well in lending some assistance!

I'm currently setup with a demand/check valve that's around 5 PSI (the manufacturer say its 5 PSI but I'm not convinced) and by running my CO2 regulator at next to no pressure I'm able to draw from the Keykeg without the flow continuing beyond the pull.

I'm going to start looking now at venting some CO2 from the keg (for reference I've currently got a Proper Job IPA 30L Slimline Keykeg on) - although I'm able to pull the beer, the foaming is beyond crazy. The 1/4 pint cylinder doesn't seem to be filling at all well, the first half of the pull is just air and a bit of foam, so its currently more like a 1/8 pint. I hope venting some CO2 from the keg will help with that, because pressure is otherwise next to nothing and the beer line couldn't be much shorter than it already is - barely 1 metre,

 

[RyanInTW]

As an extra side note, the pump although pushing out about a 1/8th pint, is drawing most of it back up again on the push back if the nozzle is submerged - I assume this is also down to the amount of foam being produced not filling the cylinder properly - a sort of vacuum effect?

 

[peebee]

Hi again Peebee! Great feedback again thanks!

I'm familiar with Dave's video, it was one of my early reference points, and he's been most helpful over FB as well in lending some assistance!

I'm currently setup with a demand/check valve that's around 5 PSI (the manufacturer say its 5 PSI but I'm not convinced) and by running my CO2 regulator at next to no pressure I'm able to draw from the Keykeg without the flow continuing beyond the pull.

I'm going to start looking now at venting some CO2 from the keg (for reference I've currently got a Proper Job IPA 30L Slimline Keykeg on) - although I'm able to pull the beer, the foaming is beyond crazy. The 1/4 pint cylinder doesn't seem to be filling at all well, the first half of the pull is just air and a bit of foam, so its currently more like a 1/8 pint. I hope venting some CO2 from the keg will help with that, because pressure is otherwise next to nothing and the beer line couldn't be much shorter than it already is - barely 1 metre,

Dave's video gives reason for the foaming (about 5 minutes in). The hand-pump causes a negative pressure (suction) and will degas over-conditioned beer - hand-pump might only manage 2-3PSI at most (some people know how to get more, but not me). Hand-pumps were never built to handle over-conditioned beer. Venting will cure it. Degassing will hugely reduce the amount of beer pumped as you've found.

The demand valves are rated for a pressure; what they will hold back. Above this rating they may fail. You say you've got your regulator set at low pressure, but ordinary beer dispense regulators are pretty naff below 10-15PSI. I use 50-150mbar propane regulators as secondaries (downstream of the primary regulator). I can also get away with these as secondaries and I guess you must be able to get them your way.

There was a couple of guys doing the same thing a bit back: http://www.thehomebrewforum.co.uk/showthread.php?t=61560. I don't know if they can be contacted for an update?

 

[peebee]

As an extra side note, the pump although pushing out about a 1/8th pint, is drawing most of it back up again on the push back if the nozzle is submerged - I assume this is also down to the amount of foam being produced not filling the cylinder properly - a sort of vacuum effect?

Sounds like the "flap" valve on the pump cylinder is worn out or imperfect, although I get a bit of it (newish pumps). I don't use the long "swan-neck" nozzles so can't dip the nozzle in the glass (the short nozzles are known as "southern pour" nozzles).

But the pump can also suck beer back because there is space for the sucked back beer - as you said, the cylinder is full of foam which will allow this.

 

[Andrew C]

Hi again Peebee! Great feedback again thanks!

I'm familiar with Dave's video, it was one of my early reference points, and he's been most helpful over FB as well in lending some assistance!

I'm currently setup with a demand/check valve that's around 5 PSI (the manufacturer say its 5 PSI but I'm not convinced) and by running my CO2 regulator at next to no pressure I'm able to draw from the Keykeg without the flow continuing beyond the pull.

I'm going to start looking now at venting some CO2 from the keg (for reference I've currently got a Proper Job IPA 30L Slimline Keykeg on) - although I'm able to pull the beer, the foaming is beyond crazy. The 1/4 pint cylinder doesn't seem to be filling at all well, the first half of the pull is just air and a bit of foam, so its currently more like a 1/8 pint. I hope venting some CO2 from the keg will help with that, because pressure is otherwise next to nothing and the beer line couldn't be much shorter than it already is - barely 1 metre,

Can you give me any tips on venting CO2 from a keykeg? I am attempting what sounds like the exact set-up that you have to pour Gipsy Hill's Doyen on a handpull. I am having the same trouble that my 1/4 pint cylinder is pulling about 1/8 with lots of foam and also some suck-back from the swan neck.

I've hooked the keg up to a jockey box to attempt the degassing instructions outlined at the end of this video from KeyKeg but I feel like this keg of English IPA isn't 'overcarbed' like a refermented brett beer for example - so CO2 isn't exactly rushing to escape. But it is obviously overcarbonated for handpull dispense. How do I bring it down?

Cheers

 

[peebee]

You've stepped outside of my knowledge of "Keykegs" now. I don't use them, but last time could draw parallels with what I do use. Venting "Keykegs" is a bit too specific for me. Did you manage to contact "Cimmeria" and "Moscow_Red" after out previous conversations?

But you've got my "treatise" on cask conditioned beer and it does go into venting (can't show pictures of my kit just now, it's in bits and being modified to be able to switch to a lower pressure gauge when the time is right). I'm sure this method can be married up to "Keykegs" in some way?

Meanwhile, if anyone else can come up with pointers here...