Spunding Valve - Commericial Style DIY

[nacho2100]

just wanted to bump this thread and subscribe. This is a really cool build

 

[pigroaster]

Keep testing. I am sure you will make the ultimate unit with all the suggestions. Please keep posting.

 

[jcaudill]

So I haven't really done a lot with this since I ended up getting a couple 40 gallon fermenters with commercial bunging valves.

The last prototype did work fine. There were an issue I never really quite worked out. The O-Ring that seals the opening between the reducing coupling and stainless ball would occasionally come unseated. Eventually I made sure that was an isolation valve before the spunding valve in case this happened so I didn't lose all my pressure. I found this most often happened in two scenarios: 1) When the valve sat idle the o-ring would often "glue" itself to the ball and/or the coupling 2) If you put too much pressure on the spring and a I think a combination of #1. In these scenarios once you started to back off the pressure once you get to a point the spring pressure is reduced enough, the pressure inside the fermenter would blow the o-ring out of place just enough it won't seal right again until you break it down and put it back in place.

I often wondered if some simple keg lube would help keep the o-ring moist. If you always break down the valve and then make sure when you reassemble you use just enough pressure to hold but not overtension maybe that would help too.

At any rate, I probably used these valves for 20 or 25 brews and despite the situation above, once I got the pressure stable it worked fine. They are big valves, but I really like being able to visually see what's going on.

I can post a final parts list up if you guys want?

 

[thefost]

I can post a final parts list up if you guys want?

Yes please!

 

[cyberbackpacker]

A final parts list would be greatly appreciated!

 

[jcaudill]

Working on making sure I have the right part numbers! Standby.

 

[jcaudill]

Here's the exploded valve:

From left to right it goes like this (all from McMaster):

Knurled Head Extension Screw - 93015A217 (has a 1/4"-20 nut attached as a lock nut)
304 SS 1" Cap - 4464K512 (two holes drilled as vents, center drilled and tapped for 1/4"-20)
18-8 SS Thumb Nut - 90368A250 (I drilled out the threads a bit so the Extension screw doesn't bind with it)
2 x 18-8 SS Washers - 96659A108 (these allow the thumb nut to rotate freely on top of the spring and provides a more even contact area)
302 SS Spring - 1986K26
440C SS Ball - 9529K24
Viton O-ring - 9464K544
1" Clear PVC Tube - 4677T23 (3" OAL)
304 SS 1" x 1/2" Reducing Coupling - 4464K534

Then adapt as necessary to connect to your fermenter. Please read previous comments about my experience with these valves. Make absolutely sure to have some form of isolation before the valve. Make sure your fermenter is pressure capable - this is hugely important to your safety and those around you! USE AT YOUR OWN RISK!

All that said, it really worked great for me! You may notice a lot of these parts require you to buy in packs. I may have some spare stuff here to put a few kits together. I may even be willing to part with the three I've built (although only 1 has the drilled SS cap - the other two I used PVC for testing). If interested, let me know here or PM.

 

[kickflip_mj]

Will some please explain a spunding valve. Im assuming its for fermenting under pressure

 

[jcaudill]

Will some please explain a spunding valve. Im assuming its for fermenting under pressure

It's for pressurized fermentation, or carbonating in the fermenter. It's a very German way of brewing (they aren't allowed to add co2 to beer so it has to be done naturally).

 

[kickflip_mj]

It's for pressurized fermentation, or carbonating in the fermenter. It's a very German way of brewing (they aren't allowed to add co2 to beer so it has to be done naturally).

Thank you! So im assuming you place a pressure gauge on a T before this and back the screw off? So say I was making an ale, when would I apply the spunding valve? (sorry I searched the web a while back and couldnt fin the answers I was looking for)

 

[nacho2100]

I wonder if you could use a torpedo head shape instead of the ball. Its the same thing the ventmatic faucets do that makes them better then the perl model. You can see a diagram on williams brewing.

What was the total price on this build if I may ask?

 

[jcaudill]

Thank you! So im assuming you place a pressure gauge on a T before this and back the screw off? So say I was making an ale, when would I apply the spunding valve? (sorry I searched the web a while back and couldnt fin the answers I was looking for)

Right you definitely want a pressure gauge somewhere before the valve. It certainly doesn't have to be close just somewhere. As to how you use it depends quite a bit on your goal. A very common use would be primary fermentation until you're within 2 Plato of your terminal gravity (sorry I work in plato) and then you shut off the blow off, build pressure and hold. How much pressure is depending on your volume of co2 and your temperature. But at 68 I would hold around 20-22 psi. As the temp ramps downward you don't need as much pressure. In commercial breweries you'll often see a max of 15psi because that is all the fermenters are rated for. So they either finish in a Brite tank, or they really cool it down.

Hope this helps!

 

[jcaudill]

I wonder if you could use a torpedo head shape instead of the ball. Its the same thing the ventmatic faucets do that makes them better then the perl model. You can see a diagram on williams brewing.

What was the total price on this build if I may ask?

Anything that would seal and sit well on the spring will work. I do think it will eventually bind with the oring if it gets dry. You'd be shocked just how sticky that oring gets. I think keg lube might help this.

Anyway - its so hard to guess how much one costs because a lot of the McMaster stuff is multiples. But I think it would run the 50-70 range for one. If you look at commercial applications you can easily spend 250 to upwards of 1000 for a similar device!