Reverse Spunding Valve for Cold Crashing

[day_trippr]

https://www.co2meter.com/blogs/news/co2-purity-grade-oxygen-purity-grade-charts

 

[SanPancho]

Spunding valve is not a regulator. Regulators take upstream flows and limit downstream pressure. Spunding valve limits upstream pressure with no regard to downstream pressure or flow. They’re not the same.

spunding valve is most correctly described as a back pressure regulating /bypass valve. that’s a hint for anyone who wants to find nice used ones on eBay.

 

[VikeMan]

The kegland spunding valves are easily reversible.

What do you mean by that?

 

[oddcopter]

What do you mean by that?

I have never done this, but the duotight fittings are easy to disconnect and there is a fitting on both sides, so perhaps, it could be reversed to pull co2 from a container (maybe a balloon) through the diaphragm into the fermenter when cold crashing.

https://www.kegland.com.au/duotight-blowtie-2-with-integrated-gauge-0-23psi.html

 

[VikeMan]

I have never done this, but the duotight fittings are easy to disconnect and there is a fitting on both sides, so perhaps, it could be reversed to pull co2 from a container (maybe a balloon) through the diaphragm into the fermenter when cold crashing.

If you want to have CO2 that has been collected in a balloon pulled back into the fermenter as pressure drops, you wouldn't want a spunding valve in between. The valve can't pull anything.

 

[oddcopter]

If you want to have CO2 that has been collected in a balloon pulled back into the fermenter as pressure drops, you wouldn't want a spunding valve in between. The valve can't pull anything.

The pulling would come from the pressure drop in the fermenter. I'll have to check if the diaphragm opens when pulled rather than pushed. The advantage might be an external source of c02 that is purged and sealed from air and only activated when pressure needs to be equalized, which might be useful in a fermenter that can't handle pressure, like a carboy.

It's probably easier to just hook up a balloon to a blow off tube near the end of fermentation, but I don't see how air doesn't get in.

All of these rigs are pretty wonky.

A pressurized Fermzilla costing $70, or a used keg even less, is so much better. Spund, carbonate, and zero suck back!