Pressure Barrels - More than you wanted to know!

Help Support The HomeBrew Forum:

The-Engineer-That-Brews

Tinkering around
Supporting Member
Joined
Jul 27, 2020
Messages
859
Reaction score
621
Location
St Albans, Herts
The pressure will drop as CO2 dissolves.
Interesting. That is certainly the received wisdom, but on the other hand when the pressure is released then (almost all) of the CO2 comes back out of solution in the form of bubbles... so there must be pressure stopping that happening, no?
 

kelper

Old Salt
Joined
Mar 4, 2019
Messages
2,998
Reaction score
1,171
Location
Highlands
It is not received wisdom! Consider the facts. Initially, the PB has water with very little dissolved gas and some air above it. You add gas. The pressure rises. Then gas starts to dissolve in the water. It follows that the pressure drops.
 

Buffers brewery

Complicated Brewer
Supporting Member
Joined
Dec 11, 2019
Messages
1,107
Reaction score
716
Location
Bognor Regis
My King Kegs are all fitted with pressure gauges. I did an experiment recently to examine just this phenomena. I almost filled a KK with water, fitted my lid and pressurised up to 12 p.s.i. with CO2. Overnight the pressure dropped to 3 p.s.i. Without making any changes I re-pressurised back to 12 p.s.i. this time using air. Over the next hour the pressure dropped to 10.5 p.s.i. and remained at 10.5 p.s.i. for a further 12 hours. I think this shows that leak testing with CO2 should only be done in conjunction with soapy water. If you’re monitoring pressure then it’s got to be air.
 

Theoriginalrich

Active Member
Joined
Sep 19, 2020
Messages
59
Reaction score
13
Whoever is offering the best price, taking delivery into account, for the configuration I want (bottom tap, black tap, stainless valve) but there’s less choice each time I look at the mo’
Hi. My son gave me a KK for Christmas. I’ve read this thread and found it very helpful. I’ve got a basket open with accessories and replacements. But why would you go for a SS valve over a brass one, is it personal preference or performance?
 

Hazelwood Brewery

Landlord.
Supporting Member
Joined
Jan 27, 2020
Messages
4,711
Reaction score
6,610
Location
Kent
Hi. My son gave me a KK for Christmas. I’ve read this thread and found it very helpful. I’ve got a basket open with accessories and replacements. But why would you go for a SS valve over a brass one, is it personal preference or performance?
Yes that’s right, personal preference, there’s no practical difference.

Pleased to hear you found it helpfulathumb..
 

Richy25

Well-Known Member
Joined
Sep 12, 2019
Messages
104
Reaction score
18
Hi guys, trying my wilko's PB again after a fail 1st time round.

1`st off what this cap spanner you speak of? I've just hand tightene mine as much as possible.

aha I see the spanner now is this must?????


2nd, I like the sound of the bicycle pump pressure test. Can someone drop a link to what valve i need to achieve this mod?

Thanks Richy
 

Ezza

Regular.
Joined
Apr 17, 2015
Messages
227
Reaction score
153
Location
Exeter
Interesting thread,so are KK the best quality PB's available to purchase?.
 

Hazelwood Brewery

Landlord.
Supporting Member
Joined
Jan 27, 2020
Messages
4,711
Reaction score
6,610
Location
Kent
The cap spanner is not essential but does make it easier to tighten the cap, it’s not so easy to get a dependable seal without one.

King Kegs are good quality kegs so less likely to suffer from cracks and pinholes from constant flexing. You still have the same potential issues with the valve and tap that cheaper kegs have.
 

Buffers brewery

Complicated Brewer
Supporting Member
Joined
Dec 11, 2019
Messages
1,107
Reaction score
716
Location
Bognor Regis
Wilko PBs are nearly half the price of a King Keg and they both have the same(ish) cap. I guess that could be a clue :confused.:
 

Richy25

Well-Known Member
Joined
Sep 12, 2019
Messages
104
Reaction score
18
Thanks for the replies guys, can anyone enlighten me will a 4" kING KEG SPANNER fit a wilko's barrel for tightening?

Also where can I get spare gaskets for wilkinson's PB's?

Looks like I have to buy another tap to get the small white tap washer ?

ARe the KK 4" cap gaskets identical and will fit wilkos?


any ideas if this holder gas is good fit for my wilkos PB?

Apologies for all the questions :)
 
Last edited:

Arcs

Landlord.
Joined
May 15, 2019
Messages
562
Reaction score
157
Location
Liverpool
Valve related issues

The most common problem people experience is a loss of pressure. Assuming the cap is well sealed against the keg (we’ll come back to that), the three ways in which gas can escape via the S30 valve are through the gas-in path, the gas-out path, or where the valve goes through the cap.

The valve seal is achieved using a thick rubber washer that gets pinched between a flange on the valve and the cap the valve is fitted to. This seal rarely leaks and when it does, it’s usually because the joint has been over tightened and the rubber washer has been distorted. In the left-hand image below you’ll see how the rubber seal is squeezed out from under the flange and is distorted through over-tightening. In the image on the right the seal is more circular and will give a better seal (we’ll return to the cable-tie). Before fitting the valve make sure there are no burrs, no raised edges, and no imperfections around the hole in the cap (also be sure not to create deep scratches or scores where the cap will come into contact with the seal) and make sure the rubber seal itself is in good condition. When fitting the valve tighten the nut as far as you can with your fingers and then use a spanner to tighten the nut another ½ to ¾ of a turn. If you over tighten the seal don’t just back off a little, undo the nut until the rubber washer moves freely and returns fully to it’s rounded shape and start again.

View attachment 31238

I noted above the gas-injection mechanism. You inject CO2 at the top and it enters the keg through the bottom of the valve, emerging from the hole in the side of the pin with the pink rubber tube over it. The rubber tube allows the gas in but stops it escaping again.

View attachment 31239

The problem people sometimes get is that when injecting CO2 the pressure of the gas not only squeezes past the pink rubber but blows the pink rubber seal clean off its pin and into your beer. If this happens you now have an open route for gas to flow back out the same way it came in AND you now can’t inject any gas until you’ve fixed the problem and your rubber seal is in your beer! This latter point isn’t so much of an issue if you have a spare rubber seal but it would be better to avoid the whole sorry story. A cable-tie tightened around the pink rubber (but not blocking the gas-in hole) is the solution. See in the third image along the hole is still clearly visible throug the pink rubber tube.

One important point though, the rubber seal also must not be pushed hard against the valve flange causing it to buckle because this also causes gas leaks so if required trim a tiny sliver from the rubber tubing.


View attachment 31240

Also just a reminder that if, when injecting CO2, the gas seems to be going everywhere except into the keg there’s a good chance this o-ring has been stretched or damaged and is no longer sealing around the neck of the CO2 bottle. It can be replaced and just sits in a groove.


View attachment 31241


By far the most common cause of trouble is the pressure-release rubber and it’s doubly frustrating for people because it almost always fails without any sign of failure! Huh?

The large brown rubber seal in the image below is the one that allows gas to escape when pressure exceeds a safe threshold – you’ll remember the gas escapes through the hole behind the rubber seal. What happens though if the rubber has become stretched and is not gripping tightly enough? The answer of course is that it will allow gas to escape at lower pressures, maybe no presure at all if the rubber is really slack. This is exactly what happens and is almost always the explanation for a leak you can’t seem to trace. The perfect-looking rubber seal in the image on the left and in the middle is the same stretched rubber you can see in the image on the right (shown next to a new rubber seal for comparison). The rubber seal streches over time and looses elasticity so although it looks fine it allows all your precious CO2 escape.


View attachment 31297


I use one of these sleeve expanders to fit the new rubber seal but it can be done with a couple of watchmakers screwdrivers or other strong & thin implements but of course be wary of nicking or piercing the rubber. When you seat the rubber seal make sure it’s centred around the groove to get the best seal.

View attachment 31298
Nice, I learned something here, excellent guide. Now I know why my ones don't work. Where am I getting this pinky seal from? :s
 

Hazelwood Brewery

Landlord.
Supporting Member
Joined
Jan 27, 2020
Messages
4,711
Reaction score
6,610
Location
Kent
Nice, I learned something here, excellent guide. Now I know why my ones don't work. Where am I getting this pinky seal from? :s
You can buy individual seals or sets. Having a quick look many suppliers seem to be out of stock at the moment but these guys seem to have some.

 

Hazelwood Brewery

Landlord.
Supporting Member
Joined
Jan 27, 2020
Messages
4,711
Reaction score
6,610
Location
Kent
Thanks for the replies guys, can anyone enlighten me will a 4" kING KEG SPANNER fit a wilko's barrel for tightening?

Also where can I get spare gaskets for wilkinson's PB's?

Looks like I have to buy another tap to get the small white tap washer ?

ARe the KK 4" cap gaskets identical and will fit wilkos?


any ideas if this holder gas is good fit for my wilkos PB?

Apologies for all the questions :)
Sorry Richy, I don’t have a Wilco PB to test this for you but there are many on the forum that have so hopefully one will have the answer for you shortly.
 

Richy25

Well-Known Member
Joined
Sep 12, 2019
Messages
104
Reaction score
18
IMG_3406.JPG


lol, 1st pint mainly head, I was so shocked at having pressure! Thank you so much @Hazelwood Brewery for this guide, it helped me try again after my 1st brew fail in PB., I wasn't holding out much hope, but followed your guide to the letter. Will buy myself a spanner and the co2 stuff know I know the dicso works properly . Was from a wilkos pressure barrel and a coopers AIPA kit. On 1st taste should have addded more hops........but I'll give it time, I like em hoppy.
Just need to workout how get more beer than head :)
 

Rodcx500z

Landlord.
Joined
Jun 10, 2019
Messages
3,458
Reaction score
2,307
Location
on the island
What did you prime with and how much, Aipa is abit fizzy for a pb, i mainly put bitter/ pale ales in mine the low carbonation ales
 

Hazelwood Brewery

Landlord.
Supporting Member
Joined
Jan 27, 2020
Messages
4,711
Reaction score
6,610
Location
Kent
View attachment 42829

lol, 1st pint mainly head, I was so shocked at having pressure! Thank you so much @Hazelwood Brewery for this guide, it helped me try again after my 1st brew fail in PB., I wasn't holding out much hope, but followed your guide to the letter. Will buy myself a spanner and the co2 stuff know I know the dicso works properly . Was from a wilkos pressure barrel and a coopers AIPA kit. On 1st taste should have addded more hops........but I'll give it time, I like em hoppy.
Just need to workout how get more beer than head :)
😂 😂 😂 Well done! 👏👏👏

The taps on pressure barrels are designed to whip up the beer a little and give it a head. When the beer is well carbonated a generous head is likely to result! Your choices are to let some of the gas out, change the tap, wait for the head to settle, scoop some of the head away with a spoon, or pour the beer into a jug and then fill your glass from the jug - the last option might be the best bet.

I am pleased the guide helped though so thanks for letting me know. athumb..
 

Latest posts

Top