King keg pressure

[KHS]

Just started on a pedigree directors in a king keg. I’m getting 3 pints off it then it’s run out of pressure, I top it up with a c02 cartridge but no pressure again after another 3 pints.
No obvious sign of pressure leak.
That can’t be right can it?

 

[Dutto]

No! You must have a leak if you carbonated the brew!

It's very seldom the tap so I suggest that you check the Cap. I always use a bit of Vaseline on mine and before I did anything I used a diamond file to make sure that the sealing surface was smooth.

Enjoy!

 

[KHS]

Cheers, I’m not 100% sure it carbonated as the previous cap definitely had a leak as I left it for a couple of weeks then found out it was totally flat. It’s a bit cloudy too.

Should I add some sugar in there and leave it for a week or so?

 

[Dutto]

Go for it!

I always check that the Keg is carbonating by taking a small glass full off after a couple of days. If it comes out with a bit of a head it means that the CO2 is being retained.

This is my current set up. I can check with a digital pressure gauge or inject CO2 as required.

 

[KHS]

Thanks. I’ve put approx 80g of sugar in. Will give it a week or so and dive back in

 

[Dutto]

Try it on Wednesday to make sure that it has started to carbonate. If it hasn't then you still have a leak!

 

[hesstondriver]

I used to seal mine with Vaseline and a couple of wraps of Clingfilm ( in the same way a plumber uses ptfe tape ) and then I used a gorilla band to make sure it was tight (in the end i got fed up with the faff and chucked it)

 

[Dutto]

I think I'll get one. It's a lot better than my current system which is to use a wood cramp!

 

[KHS]

It appears that carbonating has now started and I’ve got beer coming out without adding c02. Thanks!!

 

[KHS]

Picking back up on this, as above the carbonation process completed and the keg held pressure whilst pouring for 3 weeks. Now im about 70% through the keg the pressure run out so I topped it up with co2 again, same problem as before it only lasts 3 pints before losing pressure to nothing again.

Can’t be a leak in the keg as it kept pressure for 3 weeks following carbonation.

Any ideas?

 

[Dutto]

It may be a leak in the bits of rubber that are the Non-Return Valve (underneath the cap) and the Pressure Relief Valve (on the outside of the cap).

The two bits of rubber band perish over time and usually need replacing after a couple of years.

If you have recently replaced them then the one on the inside maybe too long and not be seating into the small "lip" that holds it in place. If this happens then the bit of tubing slides down when you introduce CO2 and allows the CO2 to escape.

The next time it runs out of pressure completely, unscrew the cap and check that it isn't over the lip. If if is then slide the tube back to where it should be and cut the bottom bit off by running a Stanley knife around the bottom just above the "lip" and removing it.

My replacement was only about 2mm longer than it should have been, but the CO2 entering the keg kept managing to blow the bit of tube down far enough so that the CO2 would escape very slowly!

I hope this is the problem and the solution 'cos it's easy enough to fix!

 

[KHS]

Thanks for the reply. Wouldn’t the keg have leaked whilst it was previously carbonating if the keg does have a leak, though?

 

[Dutto]

Thanks for the reply. Wouldn’t the keg have leaked whilst it was previously carbonating if the keg does have a leak, though?

No because the CO2 being injected into the keg is what moves the little rubber seal on the inside. The rubber seal then slips down past the lip and allows CO2 to leak backwards.

It took me ages to discover that this was my own problem.

When I renewed the perished seals, I pushed on the internal one and it sealed fine during carbonation, but then wouldn't hold pressure after I had injected some CO2.

A "quick fix" may be to leave the CO2 capsule in place on top of the keg. That way, the CO2 capsule should seal (*) the inlet and pressure won't be released backwards. If that works then it's definitely the internal seal that is either perished or displaced.

(*) If the "O" ring inside the S30 is perished or damaged then it may leak backwards.

 

[Dutto]

I used to seal mine with Vaseline and a couple of wraps of Clingfilm ( in the same way a plumber uses ptfe tape ) and then I used a gorilla band to make sure it was tight (in the end i got fed up with the faff and chucked it)

BTW, I got one of these and it works a treat on all four of my PB's! Many thanks!

https://www.amazon.co.uk/dp/B011R8ON60/?tag=skimlinks_replacement-20