Depressurise keg when reducing serving pressure?

[chrisb8]

Hi all, I'm preparing to use a corny keg for the first time. I've done a lot of reading but there's one thing I'm confused with... If you need to reduce the gas pressure - eg. when reducing the serving pressure or reducing from burst carbonation to serving pressure - do you need to disconnect the gas, then depressurise the keg and then connect the gas back on at the reduced pressure? Or do you leave everything connected and pressurised and just turn the regulator down?

I have read about the need to avoid beer being sucked up the gas line and into the regulator and so I want to get this correct in order to not make a silly mistake. My starter kit does not have a check valve but I plan to get a manifold with these built in when I hopefully upgrade to more kegs.

 

[The Baron]

Hi all, I'm preparing to use a corny keg for the first time. I've done a lot of reading but there's one thing I'm confused with... If you need to reduce the gas pressure - eg. when reducing the serving pressure or reducing from burst carbonation to serving pressure - do you need to disconnect the gas, then depressurise the keg and then connect the gas back on at the reduced pressure? Or do you leave everything connected and pressurised and just turn the regulator down?

I have read about the need to avoid beer being sucked up the gas line and into the regulator and so I want to get this correct in order to not make a silly mistake. My starter kit does not have a check valve but I plan to get a manifold with these built in when I hopefully upgrade to more kegs.

you got it right disconnect the gas then de-pressure the keg reattach the gas at your serving pressure and it will pressure the keg back up to this pressure and yes the reason is that you should never turn your pressure down with the gas attached as beer can go back into the regulator if the pressure is higher in the keg

 

[Drunkula]

The beer can only go back up the regulator if the gas line is going into the beer, part of why I take the gas dip tube out. It means after I force carb I can just knock the regulator down and wait for the gas to be absorbed and then fine tune it.

 

[chrisb8]

you got it right disconnect the gas then de-pressure the keg reattach the gas at your serving pressure and it will pressure the keg back up to this pressure and yes the reason is that you should never turn your pressure down with the gas attached as beer can go back into the regulator if the pressure is higher in the keg

Thank you for clarifying this

 

[chrisb8]

The beer can only go back up the regulator if the gas line is going into the beer, part of why I take the gas dip tube out. It means after I force carb I can just knock the regulator down and wait for the gas to be absorbed and then fine tune it.

I intend to make sure to fill the keg to below the gas in tube so in theory it should be safe anyway? I assume you are meaning that your method allows you to maximise the volume of the keg?

 

[Drunkula]

I assume you are meaning that your method allows you to maximise the volume of the keg?

Yup. If you haven't got any make sure you've got some 3/16" pipe and I'd also get a couple of inline flow restrictors. They're about 6 or 7 quid on ebay.

 

[chrisb8]

Yup. If you haven't got any make sure you've got some 3/16" pipe and I'd also get a couple of inline flow restrictors. They're about 6 or 7 quid on ebay.

Thanks for the tips, I will take a look

 

[The-Engineer-That-Brews]

To be absolutely sure beer won’t go back up the gas inlet, fit one of these (£8): https://www.themaltmiller.co.uk/product/disconnect-check-valve/

 

[AnimatedGIF]

I would recommend the set and forget method. It means you set the pressure initially and don't have to touch it until the keg is empty. The downside is it requires more patience as you have to leave it a couple of weeks to carb up. The upside is, as the name suggests, you set it and forget it. Provided you have balanced beer line or flow control, there's none of this faffing with reducing pressure.
For me, carbing pressure and serving pressure are one and the same.

 

[AnimatedGIF]

Also, +1 on the advice to use a check valve of some sort. Whilst it's easy to do things correctly, it's even easier to mess it up! It's just a very useful safety net for that one time you forget to do the right thing.

 

[Scrattajack]

Also, +1 on the advice to use a check valve of some sort. Whilst it's easy to do things correctly, it's even easier to mess it up! It's just a very useful safety net for that one time you forget to do the right thing.

For the sake of a tenner, get one. One forgetful moment...

 

[Gerryjo]

I use and Inline gas check valve like this and have never had an issue. Cheap as chips.

 

[Justin Dean]

Spunding valve. Adjust down to serving pressure using that?