Do I really need a pressure relief valve

The Homebrew Forum

Help Support The Homebrew Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Buffers brewery

Complicated Brewer
Supporting Member
Joined
Dec 11, 2019
Messages
2,358
Reaction score
2,419
Location
Bognor Regis
I’ve fitted a pressure gauge and relief/bleed valve to my King Keg pressure barrels so I can monitor the pressure for leaks but also bleed off any excess pressure if I’ve been a bit generous with the priming sugar. My current brew is conditioning and I noticed the pressure going down after the initial “carbonation” rise. The leak was traced to the rubber band pressure relief valve on the S30 assembly. I’ve managed to fix it but thought “do I really need this?” Previous experience tells me the pressure increases no more the 5 p.s.i. a day during carbonating so providing I perform a daily check I could do without. I know it sounds mad but I hate leaks!
 
I would leave it on it is there to stop damage to your keg just incase you do forget to check it but its your choice
 
I've seen some people tweaking the rubbers with cable ties or more rubber bands when they've got a bit slack. I'd definitely make sure you could test the actual release pressure doing that, though.

I'd love these guys to try and burst a pressure barrel.

 
Thanks for your thoughts guys. I liken the safety valve to travel insurance. Most of the time you don’t need it and it costs (leaks)! But there’s the fear factor of “what if....” As I’ve fitted a vent so I can easily vent any excess pressure I might try doing without the safety valve with my next brew. After all, I am a retired ol’ geezer so have plenty of time to keep an eye on the pressure.

5FEE378E-8451-4A0C-8F23-AB2427F33F28.jpeg
 
As you have a Tee already it is a small step to add a proper sprung safety valve. Most have a pull ring to vent if needed.
 
I’ve fitted a pressure gauge and relief/bleed valve to my King Keg pressure barrels so I can monitor the pressure for leaks but also bleed off any excess pressure if I’ve been a bit generous with the priming sugar. My current brew is conditioning and I noticed the pressure going down after the initial “carbonation” rise. The leak was traced to the rubber band pressure relief valve on the S30 assembly. I’ve managed to fix it but thought “do I really need this?” Previous experience tells me the pressure increases no more the 5 p.s.i. a day during carbonating so providing I perform a daily check I could do without. I know it sounds mad but I hate leaks!

Your problem is almost certainly the pressure relief rubber. As they age (even on a shelf waiting to be sold) the already stretched rubber looses elasticity. Change the pressure relief rubber and the pressure will be markedly different.

The cable tie trick @Drunkula is referring to is for solving the problem that when you inject CO2 the rubber sleeve forming the non-return valve moves and leaks or even worse blows off completely - into your beer and letting all the gas out.

See pictures below, the top picture shows the S30 valve. The pressure relief rubber you need to replace is the larger, brown, rubber sleeve. The picture in the middle shows the cable-tie trick to secure the other rubber sleeve, everyone that blows this seal into their beer adopts this practice religiously thereafter! The bottom picture is just an S30 valve replacement kit so you know what you’re looking for.

Good luck!

PS. I’m assuming your new addition isn’t leaking of course!
 

Attachments

  • B7424EE0-DB79-42E8-AB25-8B2928F8F902.jpeg
    B7424EE0-DB79-42E8-AB25-8B2928F8F902.jpeg
    25.9 KB · Views: 218
  • F872BF4B-4599-429C-A88F-2CEC98D43E7A.jpeg
    F872BF4B-4599-429C-A88F-2CEC98D43E7A.jpeg
    13.1 KB · Views: 219
  • C3A1E51C-233E-45D4-845B-E48921DE818D.jpeg
    C3A1E51C-233E-45D4-845B-E48921DE818D.jpeg
    22.3 KB · Views: 221
Your problem is almost certainly the pressure relief rubber. As they age (even on a shelf waiting to be sold) the already stretched rubber looses elasticity. Change the pressure relief rubber and the pressure will be markedly different.

The cable tie trick @Drunkula is referring to is for solving the problem that when you inject CO2 the rubber sleeve forming the non-return valve moves and leaks or even worse blows off completely - into your beer and letting all the gas out.

See pictures below, the top picture shows the S30 valve. The pressure relief rubber you need to replace is the larger, brown, rubber sleeve. The picture in the middle shows the cable-tie trick to secure the other rubber sleeve, everyone that blows this seal into their beer adopts this practice religiously thereafter! The bottom picture is just an S30 valve replacement kit so you know what you’re looking for.

Good luck!

PS. I’m assuming your new addition isn’t leaking of course!
Yep, you’re right. It was the pressure relief rubber that was leaking. I had a spare and replaced it and seems to have worked so far. I’m going to give Richie’s suggestion a try albeit a bit more expensive. Thanks for your comments though. I’ll be searching for a cable tie in the morning.
 
I would keep the pressure relief system, not only for the safety aspect but also because a ruptured PB could make a horrible mess just about anywhere!
Yeah....but.... I’m changing the rubber band safety valve for a “proper” sprung SV to see if the extra dosh is worth it.
My thinking on posting the original thread was that provided I had a way of exhausting excess pressure during carbonation over 4-5 days say the safety valve is redundant. I take everybody’s point about safety but my experience so far, albeit a bit limited, suggests that 2 pressure checks a day during carbonation would be more than adequate to get rid of the SV.
I’d be interested to hear anybody else’s experience using a proper SV with PBs.
 
I would regard keeping the two as a "belt and braces" approach.

The "rubber band" system just lets pressure off to prevent the PB from exploding it does not control the pressure below this level.

However, a Pressure Controller will control the maximum pressure at whatever pressure it is set to control and a Pressure Regulator has to be set. IF it is possible to set the pressure controller or pressure regulator at a pressure higher than the 15psi maximum pressure of the PB then I refer you to "Murphy's First Law" which is:

"If it can go wrong it will go wrong."

...........

I’d be interested to hear anybody else’s experience using a proper SV with PBs.

I have never fitted a PB with a pressure regulator ...

... but in over 30 years in the Oil and Gas business I have heard pressure relief valves lift and rupture discs blow as a result of operator error and/or pressure controllers failing!
 
I would regard keeping the two as a "belt and braces" approach.

The "rubber band" system just lets pressure off to prevent the PB from exploding it does not control the pressure below this level.

However, a Pressure Controller will control the maximum pressure at whatever pressure it is set to control and a Pressure Regulator has to be set. IF it is possible to set the pressure controller or pressure regulator at a pressure higher than the 15psi maximum pressure of the PB then I refer you to "Murphy's First Law" which is:

"If it can go wrong it will go wrong."



I have never fitted a PB with a pressure regulator ...

... but in over 30 years in the Oil and Gas business I have heard pressure relief valves lift and rupture discs blow as a result of operator error and/or pressure controllers failing!
Hi Dutto. Not thinking of using a regulator. That’s a bit OTT for a pressure barrel IMO. I’m replacing the HB valve with no SV and adding a brass SV, see pic.
7C9C4019-A91E-4FE9-B711-734BCFC0AAC1.jpeg
 
Looks good IF it is set to the PB's maximum pressure and can't be adjusted.

With regard to the Pressure Controller, using the Schrader valve set up that I have at the moment can be a bit tiresome if I have visitors. When the PB is nearly full there is very little air gap and the PB can require re-pressuring two or three times per "session".

I have Schrader Valves, similar to this one, fitted to all of my PB's ...

PB with CO2.jpg


At the moment, I am considering replacing all of the Schrader Valves with a spigot, a length of 8mm silicone tubing and one of these connectors (with the NRV bit on the PB) ...

https://www.amazon.co.uk/RELEASE-CO...?keywords=gas+connector&qid=1581528237&sr=8-7

... and then hooking the PB's up to the Growler CO2 system, which runs at 5psi.

It's still very much at the "Still thinking about it." stage!
 
Back
Top