Spunding Valve Construction For Corny Keg

I'm headed down the road to fermentation in corny kegs and the next step is construction of a nice, solid spunding valve (for fermenting under pressure, which along with Fermcap will reduce krausen and allow natural carbonation and maybe other benefits, plus transfer under pressure to a serving keg). Poindexter and WortMonger have previously posted very detailed information regarding this handy apparatus.

Spunding valve - video - shows how Poindexter put it together
Closed-system pressurized fermentation technique! - Post #39 in particular includes some McMaster part numbers

It's been several years since those posts. Following those instructions, and wishing to put together something as functional and solid as possible, I came up with the following McMaster-Carr parts list-

$31.64 - 99045K46 - Adj Pressure-Maintaining Plastic Relief Valve 1/8 NPT Female, 0.5-60 PSI (recommended by WortMonger)
$45.48 - 4066K512 - Stainless Steel-Case Gauge +/-2% Accuracy Dry, 2-1/2" Dial, 1/4" NPT Male Ctr Back, 0-60 PSI (recommended by WortMonger)
$12.58 - 5469K101 - Aluminum Manifold 2 Outlets, 1/4" NPT Inlet X 1/8" NPT Outlet
$1.29 - 4830K111 - Std-Wall Type 304/304L SS Thrd Pipe Nipple 1/8" Pipe X 3/4" Length, Fully Threaded (To connect the relief valve)
$2.44 - 4464K331 - Type 304 Stainless STL Threaded Pipe Fitting 1/8" Pipe Size, Hex Head Plug, 3000 PSI (Plug the extra hole in the manifold)
$3.23 - 5670K84 - Type 303 SS Multi-Barbed Tube Fitting Adapter for 1/4" Tube ID X 1/4" NPT Male Pipe

I like the idea of the manifold construction rather than putting it together with a tee and a bunch of tubing. I believe this would give me everything I need right up to the 1/4" barb to connect to the gas line on my corny keg. (Anyone with bright ideas on how to directly build the gas connect into this, maybe using one of these stainless steel bad boys, I'm all ears.)

The gauge and pressure relief valve are obviously the bulk of the cost. People also mention parts from Grainger-
Pressure Gauge
Pressure Relief Valve

That would bring the cost for those two parts down to the $30 range instead of $80ish, and the whole project to about $50 instead of $100. I'd just need to use a slightly different arrangement on the manifold.

Any thoughts on how to approach this project? Better to use a 0-30psi gauge for finer control? Different materials? This will spend some time in a fermentation chamber with some potential for condensation. The other possibility is a loss of krausen control and that for some foam (or more than foam, I guess) to come through here, but that's not the plan. Maybe add a check valve of some kind

Why would you spend 45 bucks on a gauge when any variety of standard 10 dollar gauges would work. There are some pretty nice gauges for 15 bucks even.

jd3 said:

Why would you spend 45 bucks on a gauge when any variety of standard 10 dollar gauges would work. There are some pretty nice gauges for 15 bucks even.

Click to expand...

The McMaster gauge and relief valve were specifically recommended by WortMonger, who has really been on the forefront of this kind of brewing, at least on HBT. But those posts were a few years ago.

I should have listed the prices to be more clear, the Grainger gauge looks reasonable to me, about $12 or so, and I was planning to use that instead unless someone had a good reason that I should use the more expensive part.

I followed this post to build mine:

https://www.homebrewtalk.com/f163/my-first-spunding-valve-231048/

I have exactly the same parts. The only difference is that I added some clear tubbing in order to see if some liquid/kreusen is coming up. It is working great.

That's perfect, I hadn't seen that post. Thanks!

If gauges are going to live in your ferm chamber and you don't want to replace them every year or so, then an all stainless gauge like the one you mention is what you want. The ones that are glycerin filled are the best and I would get that since you're going there. Think about if/how you are going to mount the gauge in your chamber (so you don't drop it and crack the casing like I did) and then you can choose the bottom or back inlet models.

I started with the 0-60 and actually have replaced with the 0-30. I went to 35 PSI once and see no reason that finer control isn't better. That is unless you are like WortMonger and trying to fully carb at 70*, doing hot lagers and what not. If I ever need to go above 30 PSI, it will be with the tank. Your choice.

I use a ganged pressure vessel (a corny) so I get no gunk in my tubing or whatnot and that's very sweet. I use my spunding valve for a lot of things and am not the biggest fan of marrying it to one fermenter or making it so I have to clean it all the time. Mine is very transportable and I do 3 keg at once tandem corny filling from one sanke and it works flawlessly. Because of the spunding valve, all 3 receiving kegs are the same pressure and fill at exactly the same rate and end with exactly the same headspace, which is great if I need to adjust any carb levels with the tank.

I use this manifold to do that: Part #: 5465K71

As far as krausen passing thru a post with the poppit still in place, well, I wouldn't do that, but that's my opinion. That's a pretty small diameter opening and well, yikes! I guess with my ganged corny, I have the luxury of having that opinion though. No poppits from the sanke to the corny but there is one on the gas out of the corny where my spunder is.

You didn't mention how big your batches are or plan on being but if I were you (and I do 15 gals) I would set up my spunding valve so I could pressure ferment 3 kegs (of the same wort) at once with just the one valve.

I'm not getting what you mean by using a check valve. If you put your spunder right on your corny gas out and fill your fermenter up to as high as possible, you are going to get crap in your $100 spunder and have to clean it every time. Those guys who are putting the spunder right on the fermenter are not pushing final volume like I am... (I believe). I am doing 14.5 gals in a 15.5 sanke and definitely wouldn't want to do without my ganged corny. If you are doing 5 gal batches in a 5 gal corny, I think you'd want to engineer your valve differently than right off of the post. IMO.

You might consider fermenting in a sanke. You could just as easily build a much larger fermentation vessel and have no worries about krausen gunking up your spunding valve.

Here's mine. King of a frankenstein, but it works great. I added a quick connect from home depot to attach to a co2 tank for pushing out fluids and pressurizing whenever I want.


If you do or are considering 10 gallon batches, a sanke is really nice option. Cleaning is basically a non issue. Just soak in oxy. Rinse. sanitize as you normally would. Mine is sparkling clean after each batch.

dflipse said:

I'm headed down the road to fermentation in corny kegs and the next step is construction of a nice, solid spunding valve ...

Click to expand...

Just checking in with you to see what your status is? Did you make a spunding valve and how's that corny fermentation process coming along. We need pictures or it didn't happen...

They have these at brewmasterwarehouse for 22 dollars...

TJTHEBEST said:

They have these at brewmasterwarehouse for 22 dollars...

Click to expand...

Can you post a link?

pickles said:

Can you post a link?

Click to expand...

http://www.brewmasterswarehouse.com/product/0101784/bleeder-valve is the part on Brewmasters Warehouse the above poster is referring to, I believe. I haven't looked into it, but I'm not sure that's a pressure relief valve on there. That might be just a gauge and a valve you have to open or close manually. Austin Homebrew Supply sells the same piece (http://www.austinhomebrew.com/product_info.php?products_id=10397) and they're a bit more descriptive, but I'm not sure. If it's an adjustable pressure relief valve, the price is definitely right.

1MadScientist said:

Just checking in with you to see what your status is? Did you make a spunding valve and how's that corny fermentation process coming along. We need pictures or it didn't happen...

Click to expand...

I'm totally busted. I never followed through in this thread, though I did make a spunding valve and (after moving cross-state, new job, new brewing setup, etc) am now fermenting my first batch of homebrew in a 5 gallon corny keg.

Pics, cause it is happening (though only crappy iPhone pics, cause I worked overnight)-

That's my fermentation fridge, as well as the place I store the rest of the brewing gear. More on that (chiefly my Reflectix and Line-X coated e-Kettle) another time.


The spunding valve in situ, though it's sorta hard to tell in the picture.


Better shot of the spunding valve itself.

I used about 4 feet of clear line to be able to tell if anything is escaping the keg and to try to capture it if it does. First batch, pretty darn full keg, nothing but some vapor in the line.

McMaster parts list-
4089K12 Multipurpose Gauge +/-2% Mid-Scale Accuracy, 2" Dial, 1/4" NPT Male Bottom, 0 - 30 PSI 8.52
4429K223 Low-Pressure Brass Threaded Pipe Fitting, 1/4" X 1/8" X 1/4" Pipe Size, Inline Reducing Tee 9.89
9171K212 Precision High-Pressure Brass Thread Pipe Fitting, 1/8" X 1/8" Pipe Size, Hex Nipple, 5600 PSI, 1-1/16" L 3.58
99045K44 Adjustable Pressure-Maintaining Plastic Relief Valve, 1/8 NPT Female, 0.5-30 PSI 31.64
50675K162 Brass 37 Degree Flared Tube Fitting, Adapter for 1/4" Tube OD X 1/4" NPT Male Pipe 2.12

This could definitely be done more cheaply, but I've really liked how this worked out. It's very compact. The device just sits on top of the keg. I'm just about 10 days into this fermentation.

A really slick project would be to mount it outside the fridge itself (pass through the door/top as in a kegerator) and you could monitor fermentation without ever opening the door of the fridge. Tighten the valve a bit, the pressure should rise over a few hours. Doesn't happen? Fermentation isn't happening.

dflipse said:

I'm totally busted. I never followed through in this thread, though I did make a spunding valve and (after moving cross-state, new job, new brewing setup, etc) am now fermenting my first batch of homebrew in a 5 gallon corny keg.

A really slick project would be to mount it outside the fridge itself (pass through the door/top as in a kegerator) and you could monitor fermentation without ever opening the door of the fridge. Tighten the valve a bit, the pressure should rise over a few hours. Doesn't happen? Fermentation isn't happening.

Click to expand...

dflipse, A "BIG Thank You" for posting back and with the parts list too. I ordered from McM-C for it all, except I had the ss fittings from a previous build, I did need to order the 1/2 to 1/8 bushing too.

Note my hole in the door. I already had one, I just enlarged it.

I am on my way now. See my latest pictures here; http://www.flickr.com/photos/madscientistbrewhaus/

Regards... Richard

Thanks dflipse...

I just ordered the same parts to copy your build so I can control my carbonation while lagering... among other uses.

Here's an updated McMaster-Carr parts list with prices as of 14SEP12

1 each 4089K61 Multipurpose Gauge Plastic Case, 2" Dial, 1/4 NPT Bottom, 0-30 PSI $9.20 each
1 each 4429K223 Low-Pressure Brass Threaded Pipe Fitting 1/4 X 1/8 X 1/4 Pipe Size, Inline Reducing Tee $11.87 each
1 each 9171K212 Precision HI-Pressure Brass Thrd Pipe Fitting 1/8 X 1/8 Pipe Size X 1-1/6" Length, Hex Nipple $3.87 each
1 each 99045K11 Adj Pressure-Maintaining Plastic Relief Valve 1/8 NPT Female, 0.5-30 PSI $36.88 each
1 each 50675K162 Brass 37 Degree Flared Tube Fitting Adapter for 1/4" Tube OD X 1/4" NPT Male Pipe $2.21 each

Merchandise total
$64.03

-kal

Updated photo with parts list as of 9/1712.

-kal

TJTHEBEST said:

http://www.brewmasterswarehouse.com/product/0101784/bleeder-valve

Click to expand...

That's not a variable pressure relief valve. It's a manual on/off valve with a pressure gauge attached. Doesn't work for these purposes (unless you can train a gremlin to sit next to your fermentor all day).

is the relief valve the same you would use to regulate the psi for an air compressor?

I have an old regulator that I acquired which doesn't work that great as a regulator I was going to try and repurpose it as a spunding. Is that possible?

Morebeer do sell these with a gauge and adjustable pressure relief valve, attached to a ball lock gas QD for $35 (or $20 without the gauge). I have one, and it works well.

http://morebeer.com/products/ball-lock-qd-adjustable-pressure-valve-wgauge.html

I guess you could part one out a little cheaper if you can find the pressure relief valve cheaply. I couldn't, so I bought this. I wouldn't normally post products, but this is lot cheaper than some of the parts bills upthread.

dyqik said:

Morebeer do sell these with a gauge and adjustable pressure relief valve, attached to a ball lock gas QD for $35 (or $20 without the gauge). I have one, and it works well.

http://morebeer.com/products/ball-lock-qd-adjustable-pressure-valve-wgauge.html

I guess you could part one out a little cheaper if you can find the pressure relief valve cheaply. I couldn't, so I bought this. I wouldn't normally post products, but this is lot cheaper than some of the parts bills upthread.

Click to expand...

What is the pressure lease valve for? I'm guessing you put this on the keg to get an accurate say 10 psi since the rest of the pressure if set at 30 will bleed off? I mostly want one to just test my kegs to see if they are holding pressure after I repair them, so I probably don't need a valve?

You wouldn't need to valve to just monitor the internal pressure. The sounding valve allows you to control pressure during fermentation, pressure transfer beer to a keg, among other things.

theck said:

What is the pressure lease valve for? I'm guessing you put this on the keg to get an accurate say 10 psi since the rest of the pressure if set at 30 will bleed off? I mostly want one to just test my kegs to see if they are holding pressure after I repair them, so I probably don't need a valve?

Click to expand...

The pressure relief valve is what makes it a spunding valve. The gauge is just to help set the valve.

so is the morebeer.com part indeed a spunding valve?
http://morebeer.com/products/ball-lock-qd-adjustable-pressure-valve-wgauge.html

Is that the best one to buy if I'm not going to put it together myself?

thanks

Yes that appears to be adjustable sounding valve so it would work. Although it doesn't look all that easy to adjust. Another thing to consider is the internal components. If they're carbon steel it'll rust and likely not vent properly or at all. We've seen this issue on this thread.

pjcampbell said:

so is the morebeer.com part indeed a spunding valve?
http://morebeer.com/products/ball-lock-qd-adjustable-pressure-valve-wgauge.html

Is that the best one to buy if I'm not going to put it together myself?

thanks

Click to expand...

Yes, that is a spunding valve, and it is adjustable. I have one. It's pretty easy to adjust - hit the keg with some co2 pressure to seat the lid then adjust the valve down to your desired pressure. You can then vent again to let pressure build up naturally if you like.

OK, I bought that valve from morebeer.com.

http://morebeer.com/products/ball-lock-qd-adjustable-pressure-valve-wgauge.html

It does not hold pressure.

A rep from morebeer.com has explained to me that it is not meant to, quote:
"...The product is used to filter between two kegs. One keg will be under CO2 pressure to push the beer to the other keg through a filter, and the second keg will have the relief valve, so you can adjust the pressure that needs to be released. If you connect it to a keg that had 30 psi pressure added to it, it is understandable that it will drop to 0 psi when the keg is emptied of CO2..."

Which makes sense if you look at the construction of the valve.

So now I'm all confused. Do the McMaster / Grainger valves hold pressure? I thought the valve was to be left on the keg to bleed off excess pressure from that set on the pressure gauge.

What's going on, Batman?

The McMaster one does hold pressure. That one should too. I'm assuming it's just a spring and ball in a housing. The ball seals against a seat, the amount pressure it holds is relative to the compression added to the spring. I think the rep is a bit confused by what you're trying to do. Spunding is the same as pressure transfer really. You have a constant supply of co2 that you want to regulate at a given pressure.

Pickles,
Thanks for helping me out of a pickle. Hey!

OK, here's what I done.
Took an empty corny keg and hit it with 30 psi to seal the lid O ring.
Disconnected the CO2 cylinder from the keg.
Put the spud on the keg and set it at 7 psi.
An hour later I went back and it was almost at 0 psi.
(I tried this twice, to to make sure before I contacted morebeer.com)
So are you saying their spud is not working correctly?
Obviously this is no good for the pressurized fermentation procedure I'm hoping to try.

Cheers!

It's actually no good for what they claim it's intended use is either if it truly leaks pressure. I don't own a morebeer version but I've used dozens from McMaster (two in home brewing for pressure relief and dozens at work for vacuum relief in air sampling pumps; they are so simple that all you have to do is reverse the spring and ball depending on the situation) and the do work for our purpose; although not very very accurate or precise.

Octavius said:

Pickles,
Thanks for helping me out of a pickle. Hey!

OK, here's what I done.
Took an empty corny keg and hit it with 30 psi to seal the lid O ring.
Disconnected the CO2 cylinder from the keg.
Put the spud on the keg and set it at 7 psi.
An hour later I went back and it was almost at 0 psi.
(I tried this twice, to to make sure before I contacted morebeer.com)
So are you saying their spud is not working correctly?
Obviously this is no good for the pressurized fermentation procedure I'm hoping to try.

Cheers!

Click to expand...

How do you know your keg isn't leaking? Did you soap test it?

Acidrain,
Good thinking but, yes, I did spray the top of the keg with Starsan and there was no leak.

This particular valve has exactly 3 1/2 turns in it before everything falls out:



(Incidentally, this arrangement DID leak -from the nipple connecting the gauge- when I first started looking at it. I took everything apart and carefully re-did all the connections with teflon. I'm 100% confident the connections should not now leak. The (slow) leak is coming from the valve itself).

Pickles,
Perhaps it works for what morebeer.com advertize it for - if you do the beer filtering transfer and then immediately remove the valve.

Still a bit of a mystery. It shouldn't leak but it does.

Cheers!

Octavius said:

OK, I bought that valve from morebeer.com.

http://morebeer.com/products/ball-lock-qd-adjustable-pressure-valve-wgauge.html

It does not hold pressure.

A rep from morebeer.com has explained to me that it is not meant to, quote:
"...The product is used to filter between two kegs. One keg will be under CO2 pressure to push the beer to the other keg through a filter, and the second keg will have the relief valve, so you can adjust the pressure that needs to be released. If you connect it to a keg that had 30 psi pressure added to it, it is understandable that it will drop to 0 psi when the keg is emptied of CO2..."

Which makes sense if you look at the construction of the valve.

So now I'm all confused. Do the McMaster / Grainger valves hold pressure? I thought the valve was to be left on the keg to bleed off excess pressure from that set on the pressure gauge.

What's going on, Batman?

Click to expand...

The morebeer representative seems to not understand the set up. You are not releasing all the CO2 pressure from the keg, and the fermentation in the keg is producing CO2. If you connect a pressure relief valve to an otherwise sealed keg that is producing CO2, it should release excess CO2 from the keg, and reseal when the pressure drops below the set point. If your pressure went to zero, then your pressure relief valve isn't sealing properly when the pressure drops below its set point. It might be that there's a very slow leak from this design of valve though. Proper reseating on PRVs is something that should be designed in though. A little keg lube on the seat could help.

So far, mine has worked perfectly (used during natural carbonation) - pressure held at 6psi for a week, while carbing (aiming for low carbonation for a best bitter, racked to keg a little before FG, and primed to make sure it carbed enough)

I totally agree. Morebeer sold you a defective unit, whether it's the design or that specific unit I don't know.

Thanks for trying to help me out guys.

morebeer.com is still insisting that it is not defective. Here is another email I just received:

"This item is made to be connected to one keg while the other keg is connected to a CO2 tank and also connected through a filter to the first keg. If you put 30 PSI of pressure into one keg, and disconnect the CO2 tank, the relief valve will release all of the CO2 from your keg until there is no CO2 left in the keg, which is why the relief valve gauge is dropping down to 0 PSI.

If you would like to return this part, please fill out our return form at http://morebeer.com/content/return and we will email you the proper return shipping address and an RMA number. You will be responsible for the return shipping."

It's going back to them but it irks me I have to pay shipping.

How long did it take for the pressure to drop to zero? Was it simply absorbing the CO2 you put in to seal the o-ring? That CO2 will dissolve and the pressure drop, then it will rise again once the yeast start producing CO2. The timing is important there.

If it is dropping fast (which it seems to be and what their CS rep says it should), then it is a pressure relief valve that is designed for 0PSI, any positive pressure at all will release. This is what a normal person would call a check valve. Darn marketing people strike again.

But morebeer advertises it as "adjustable". Clearly this thing is set to 0 cause it leaks.

Based on the design it should be adjustable - by backing out the threaded portion you would reduce spring pressure and decrease the pressure needed to vent. It is likely a problem of the o-ring not sealing. I might try wetting the o-ring just to see if it helps. If it does maybe replace the water with some keg lube. But if you're going to return it don't go straight to lube, they may not want to give you full credit.

John and Pickles,
Thanks for the help - I was going to set up another experiment for you all but just got this email from morebeer.com.

"It is not a spunding valve unfortunately, if you refer to the product page (http://morebeer.com/products/ball-lock-qd-adjustable-pressure-valve-wgauge.html) you will see it is meant as a simple relief valve to adjust how much pressure is released during the filtering process."

I think that settles it.

Cheers everyone. (I'm looking at McMaster-Carr now.)

Wow, Octavius you are making this overly complicated. Building a spunding valve is dead easy. Literally a 10 minute project once the parts are in hand.

And you can use it to bleed one keg while pushing from another too (spunding valve is cropped off in this pic but you can see where attached on the receiving keg's gas post).


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Hmmm...using new verion of app...pics did not post. Trying again.

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