Spike All-In-One PRV and Cold Crashing

[Nagorg]

Hey HBT!

I recently picked up a Spike All-In-One PRV for my CF10. I'm wanting to use it during a cold crash with a CO2 bottle attached so that it can provide gas during this process with the fermenter sealed off.

I don't use glycol so my conical sits inside an upright freezer as a fermentation chamber. During the cold crash event, ambient temps inside the chamber can get well below freezing since the actual beer temp detected by the probe in the thermowell doesn't change as fast as ambient.

Can anyone comment if these very low, sub-freezing, temperatures might not be so good for the pressure gauge on the PRV? I *think* its oil filled and the answer to this may depend on the type of oil its filled with.

As a second but related question, any concerns for my CO2 regulator in this same scenario? I'd have my CO2 bottle inside the fermentation chamber with the conical during these times of sub-freezing temperatures.

Any insight is much appreciated!

 

[Broothru]

Hey HBT!

I recently picked up a Spike All-In-One PRV for my CF10. I'm wanting to use it during a cold crash with a CO2 bottle attached so that it can provide gas during this process with the fermenter sealed off.

I don't use glycol so my conical sits inside an upright freezer as a fermentation chamber. During the cold crash event, ambient temps inside the chamber can get well below freezing since the actual beer temp detected by the probe in the thermowell doesn't change as fast as ambient.

Can anyone comment if these very low, sub-freezing, temperatures might not be so good for the pressure gauge on the PRV? I *think* its oil filled and the answer to this may depend on the type of oil its filled with.

As a second but related question, any concerns for my CO2 regulator in this same scenario? I'd have my CO2 bottle inside the fermentation chamber with the conical during these times of sub-freezing temperatures.

Any insight is much appreciated!

The fill fluid is glycerol which freezes at -38C, or -36F.

You’re wise to have pressure to keep the tank from imploding if sealed. If your vessel is capable of being pressurized, you can pre-charge the vessel to allow for the pressure drop rather than leaving a CO2 supply hooked up. Since I spund and cold crash in the same tank, I’m already starting at 1BAR pressure. I don’t think I’ve seen more than a 6~8 psig drop between ambient temperature (65F-75F) down to ~35F cold crash temperature, but that drop in differential vacuum (6-8 psig) on a sealed tank would likely cause it to collapse if not vented.

 

[Nagorg]

I hadn't considered just pressurizing the sealed CF10 instead of leaving the CO2 attached and under pressure. According to Spike Brewing, the CF10 is rated for a working pressure of 15 psi. So I could pressurize to say ~8-10 psi, disconnect the gas and start the cold crash.

This would probably work assuming the tank doesn't leak! But then if it leaks, I'd probably dump all of my CO2 during the process anyway. Plus risk a collapsed tank.

Sounds like the least of my concern should be the gauge.

 

[DavidWood2115]

If your tank leaks, it should leak equally as much under negative pressure as under positive pressure. All of your seals are symmetric.

The only one-way device is your Spunding valve, but that shouldn’t be leaking.

 

[bailey mountain brewer]

Put 10 psi on it, walk away for a few hours and check it. Or even overnight. If no change start your crash. I'd still check it atleast once a day as a leak could develop during the temp change. You can also snug up your clamps once thing start to cool down in there.

 

[Broothru]

I hadn't considered just pressurizing the sealed CF10 instead of leaving the CO2 attached and under pressure. According to Spike Brewing, the CF10 is rated for a working pressure of 15 psi. So I could pressurize to say ~8-10 psi, disconnect the gas and start the cold crash.

This would probably work assuming the tank doesn't leak! But then if it leaks, I'd probably dump all of my CO2 during the process anyway. Plus risk a collapsed tank.

Sounds like the least of my concern should be the gauge.

By all means, since the CF10 is rated for 15 psig working pressure bump it to 1 BAR/14.7 psi. That'll give you plenty of room (or more correctly, 'vacuum') to play with while still maintaining positive pressure. You'll also be half way there towards having your beer carbed up for serving!