Spike Gas Manifold Safety Warning

[Jag75]

Ouch did craft brewers kick your dog or something? What made you feel only macro breweries are reputable? we have lots of excellent smaller breweries making beers other than mass produced lagers that are very reputable. cheers

I was kidding man

 

[Blazinlow86]

I was kidding man

Aha damn Internet. It can be hard to tell sometimes. As majority of Craft breweries use a blowoff setup and typically aren't makings macro style lagers like the examples posted I thought you were taking a jab at them. Cheers

 

[chpueblo22]

A spunding valve has an ID of 1"+. There is more force pushing up on the PRV with the larger diameter and the krausen can actually bubble through the larger openings rather than clogging. Even with a spunding valve we recommend using our PRV as it is designed to pop at 15psi. We would not recommend a Blichmann spunding valve as it has the same potential for clogging. We'd recommend a pro style similar to the ones SS and Stout offer. The key is the larger ID opening.

Looking at building my own manifold for spunding, pressure fermentation, transfers for my new CF10s and had a couple questions.

1) Is this the type of spunding valve you are referring to in the first picture?
2) Is there a downside to using the type of PRV I show in the second picture? It notes having a vacuum break which I imagine would work by letting air in. Assuming I keep pressure while cold crashing though, I'm not sure this would matter or is it better to get a prv without vacuum break?

Currently planning to use a 4 way 1.5" TC cross from top port with prv, ball lock disconnect, and this elbow spunding valve with pressure gauge on third port. A little overkill but I think that would check all the things I could possibly want to do.

 

[Vale71]

1) Is this the type of spunding valve you are referring to in the first picture?

That is a pro-grade a spunding valve and it's pefectly suited. You can get one without the manometer if your tank already has one.

2) Is there a downside to using the type of PRV I show in the second picture? It notes having a vacuum break which I imagine would work by letting air in. Assuming I keep pressure while cold crashing though, I'm not sure this would matter or is it better to get a prv without vacuum break?

Having a vacuum break is not essential but it's definitely a plus and won't hurt your tank's performance in any way.

Currently planning to use a 4 way 1.5" TC cross from top port with prv, ball lock disconnect, and this elbow spunding valve with pressure gauge on third port. A little overkill but I think that would check all the things I could possibly want to do.

You clearly haven't seen my fermenter. I got so much stuff attached at the top I'm afraid one day it's going to fall over from the sheer weight of the accesories...

 

[Broothru]

That is a pro-grade a spunding valve and it's pefectly suited. You can get one without the manometer if your tank already has one.


Having a vacuum break is not essential but it's definitely a plus and won't hurt your tank's performance in any way.

You clearly haven't seen my fermenter. I got so much stuff attached at the top I'm afraid one day it's going to fall over from the sheer weight of the accesories...

My only question would be 'where' on the fermenter is the spunding valve mounted in Pic #1? I have a nearly identical spunding valve to the one pictured. The connection fitting comes off a T that comes off the top mounted blow-off pipe. Upstream of the spunding valve on the blow-off is a diaphragm pressure gauge, and since the bottom is a frangible seal it cannot be clogged by krausen and will always give an accurate internal pressure reading of the fermenter. Downstream of the spunding valve is a ball valve shut-off and discharge line into a sanitizer-filled jar.

So the setup is: top-mounted blow-off pipe, "T" junction to pressure gauge, "T" junction to spunding valve, ball valve shut-off, discharge bucket. I always have 3" TC mounted PRV with vacuum break at the top of the tank identical to the one in Pic #2, and it's attached whenever any fermentation is going on regardless of pressurized or unpressurized. I'm reasonably confident that this affords me a comfortable and acceptable level of safety with independent redundant sources of backup. I ferment unpressurized until ~5 points of predicted Final Gravity, then close the ball valve on the blow-off pipe and set the spunding valve to 1 bar ~ 14.7 psig. I get carbonated beer that conditions at least a week sooner that's already at serving temperature when it gets pressure transferred to a purged serving keg.

With all that said, something I've noted in the discussion on this thread is the conflating of spunding with pressurized fermentation, which as you pointed out are two different (yet similar) processes. Even though spunding involves pressurization, I think it is best thought of as completing fermentation under partial pressure. As you also pointed out, macro brewers pressure ferment lagers at up to 3 bar with a specific temperature profile that varies as the fermentation progresses to control (speed up) the time to completion of fermentation as well as shape the ester production of the fermentation. Those temperature/pressure profiles are also most certainly tied to specific yeast strains, so one size doesn't necessarily fit all. True, pressurized fermentation does carbonate the beer, but it isn't the same thing as spunding. Or more accurately, spunding is not technically the same thing as pressurized fermentation, which is an expansion of the spunding process.

One other item that has been overlooked in this thread is that fermentation under pressure tends to suppress the formation of krausen in the fermenter. But this factor can also create risk. At a low pressure, say 3~5 psi, a home brewer might think they are "safe" because krausen is suppressed, therefore no worry of a blocked spunding valve. Suppress does not mean eliminate, and the amount of suppression varies with pressurization. The amount of suppression at 14.7 psig is much greater than 3~5 psig. Three to 5 psig fermentation "under pressure" probably presents a significantly larger possibility of a clogged blow-off pipe or spunding valve, especially if the spund is set too soon during fermentation.

In any event, safety and precaution should always take precedence when dealing with pressurized fluids. In the 'good old days' of home brewing, everybody used plastic buckets and glass carboys with rubber stoppers held in place with the tenuous bond of friction. An over-pressure due to a blocked airlock or over-aggressive primary fermentation was solved when the airlock popped out or the top seal of the bucket worked loose and krausen slopped onto the floor or counter top. It made a mess, but in the end it wasn't a big deal. Now with the advent of stainless steel vessels capable of holding significantly higher pressure, we have a two-edged sword that on the one hand allows us to do things in brewing that only professionals could do a few years before, but on the other hand can create very real hidden dangers that may not be obvious to the amateur brewer who is not familiar with the risks associated with high pressure fluids.

Whatever motivated Spike to issue their warning to users shouldn't be the bottom line issue. What's important and mandatory is that end users, especially home brewers, are made aware of the inherent risks and not blindly making modifications to their gear (or using the gear improperly) which could result in a hazardous and potentially deadly situation. I salute Spike's action.

Brooo Brother

 

[chpueblo22]

My only question would be 'where' on the fermenter is the spunding valve mounted in Pic #1? I have a nearly identical spunding valve to the one pictured. The connection fitting comes off a T that comes off the top mounted blow-off pipe. Upstream of the spunding valve on the blow-off is a diaphragm pressure gauge, and since the bottom is a frangible seal it cannot be clogged by krausen and will always give an accurate internal pressure reading of the fermenter. Downstream of the spunding valve is a ball valve shut-off and discharge line into a sanitizer-filled jar.

Brooo Brother

Thanks for the detailed reply. Attached photo is the set up I was thinking. Would allow me to use blow off tube for majority of fermentation and like you mentioned, shut it off during final portions to build up some pressure. My primary goal is to minimize cold side oxidation and I like the idea of being able to use spunding valve (or to force carbonate for pressure transfer) without having to take anything off (i.e. switching from blow off tube to gas manifold). Less interested with pressure fermentation although I am looking to do a lot of lagering so I wouldn't rule it out.

This set-up seem reasonable? overkill? any ways you can see to minimize bulk and accomplish same goals? It seems like only way using a spike unitank given they only have one 1.5" TC port on top.

 

[Broothru]

From your sketch it looks like you'd have all the bases pretty much covered. I didn't quite understand how you had planned to used the spund/PRV piece in your original post, but now I see you plan a top mount on a 4-way "T" manifold mounted on top of the fermenter. I'm assuming 1.5" TC pipe flange fitting, so probably 1" ID tubing. That, plus the top mounting should mitigate concerns over krausen clogging the works, and having a pressure gauge and a dedicated 'industrial strength' PRV gives you the ability to monitor any dangerous pressure buildup while having a dedicated safety relief.

The one thing I would suggest is to make sure the valve on your blow-off line is a large bore butterfly valve and not a ball valve. It's a bit more expensive, but the lowest 'choke point' on your design (where rising krausen might possibly collect) is right there. A ¾" diameter bore butterfly valve instead of a smaller bore ball valve would mitigate that possibility, as would a domed lid if that's a possible retrofit (not sure what brand/model fermenter you have).

You could also possibly streamline the design by having a 2-way "T" mounted on the top of the fermenter with one side attached to the dedicated PRV and the second side attaching to a manifold that clamps to the side of the fermenter. That manifold would be your blow-off cane and have additional "T" connections for both a side mounted pressure gauge and spunding valve, and end with a ball or butterfly valve so you can either pressurize the tank or vent into a blow-off bucket. This configuration would take a lot of hardware off the top of the fermenter and make it more vertically stable.

The bottom line safety concern is to make sure you have a dedicated PRV mounted high enough on the fermenter to be unaffected by rising krausen, connected with a large enough diameter pipe that krausen won't someday block it (pipe and/or PRV). Even more important is NEVER having any valve or shutoff device placed between the PRV and the inside of the tank. Mr. Murphy and his Laws dictate that sooner or later someone will mis-position that valve at the worst possible time and bad things could/might/will certainly happen. Don't allow yourself to ever be that person.

Brooo Brother

 

[balrog]

I wonder; somehow related? ...
https://www.homebrewtalk.com/forum/threads/how-much-pressure-can-fermentation-build-up.675384/

 

[Broothru]

Thanks for the detailed reply. Attached photo is the set up I was thinking. Would allow me to use blow off tube for majority of fermentation and like you mentioned, shut it off during final portions to build up some pressure. My primary goal is to minimize cold side oxidation and I like the idea of being able to use spunding valve (or to force carbonate for pressure transfer) without having to take anything off (i.e. switching from blow off tube to gas manifold). Less interested with pressure fermentation although I am looking to do a lot of lagering so I wouldn't rule it out.

This set-up seem reasonable? overkill? any ways you can see to minimize bulk and accomplish same goals? It seems like only way using a spike unitank given they only have one 1.5" TC port on top.

After re-reading your posts I see that you have a Spike CF-10 which is a unitank with a semi-domed top. IIRC, Spike offers a sight glass type lid for some of its tanks (maybe the 4" top TC?). I'm guessing if you bought the unitank with the notion to brew lagers you probably got cooling coils for that 4" TC, but if not that would be a great place to attach your 4-way "T" manifold rather than the 1.5" TC on the periphery of the lid. On the 1.5" mounting, I'd probably go with a 2-way "T" manifold with PRV, and vertically build the other accessories "down the side" if you have or are considering a chilling coil for the 4" TC. There would just be too much stuff on top with glycol lines and a 4-way manifold with all the attachments.

I lucked out with my SS Brew Tech unitank since it has a 8" TC mounted cooling coil with an integrated 3" TC reducer in the middle of the cap that holds a dedicated PRV. My manifold with pressure gauge and spunding valve are incorporated in the blow-off line on the side of the fermenter with a ball valve at the end for capping and pressurizing the tank. The PRV is always mounted in the center of the cooling coil cap, out of the way of glycol lines. It makes for a very clean and uncluttered, as well as highly efficient, setup. And I use it exactly how you plan to use yours. I'm very happy and impressed with what is available to home brewers these days. But with that ability also comes the responsibility to be mindful of potential unseen risks, just as with any other advanced tool.

Happy (and safe) brewing,

Brooo Brother

 

[Vale71]

Thanks for the detailed reply. Attached photo is the set up I was thinking. Would allow me to use blow off tube for majority of fermentation and like you mentioned, shut it off during final portions to build up some pressure. My primary goal is to minimize cold side oxidation and I like the idea of being able to use spunding valve (or to force carbonate for pressure transfer) without having to take anything off (i.e. switching from blow off tube to gas manifold). Less interested with pressure fermentation although I am looking to do a lot of lagering so I wouldn't rule it out.

This set-up seem reasonable? overkill? any ways you can see to minimize bulk and accomplish same goals? It seems like only way using a spike unitank given they only have one 1.5" TC port on top.

It's perfect but you're probably getting close to the fermenter's tipping point, at least when it's empty...

 

[Broothru]

I wonder; somehow related? ...
https://www.homebrewtalk.com/forum/threads/how-much-pressure-can-fermentation-build-up.675384/

Valid discussion about pressure killing, or at least suppressing, continued fermentation. And let's not forget alcohol concentration killing yeast. So there are several self-limiting factors to a runaway fermentation. That said, one poster made the comment that 100 psi might be the limiting pressure for yeast viability. Of course a keg rated at 130 psi could hold that pressure. On the other had, a unitank with a rated operating pressure of 15 psig can be assumed to have a burst/failure pressure somewhere less than 30 psig. That's a significant difference, orders of magnitude even. Which is why dedicated PRVs are essential and should be mandatory to protect against both the "stupid gene" and Darwinian evolution, neither of which afford us adequate protection from ourselves or our peers in home brewing.

Brooo Brother

 

[Broothru]

It's perfect but you're probably getting close to the fermenter's tipping point, at least when it's empty...

Solution? Never leave it empty!

 

[sensei247]

Good thread...one main question . I’m building a fully automated Arduino driven fermentation controller and want to ensure pressure (positive and negative) can be mechanically prevented given computer programming will drive this process. Mechanically, I’m making a safety assumption there could be faulty sensors, gas leaks, bad calibration, etc and want to ensure I’m protected.

If I use the spike gas manifold with PRV (blowoff supposedly at 14-15psi) do I also need a vacuum breaker to account for negative pressure AND spunding valve (all 3 pictured below)? Have seen threads that suggest adding this 3rd and final mechanical safety being a spunding valve added to the unitank as well.

Alternatively, I’m wondering if I could use ONLY the 1bar vacuum breaker as this is all being connected via a 4-way TC attached to Spike unitank lid.

Any thoughts?

 

[Broothru]

There are probably a near infinite number of ways to achieve what you want to do. As you've probably gathered from this thread, some of those ways can be very dangerous. Always proceed with caution. First Rule: never have ANY closable valve between the tank and your PRV. If at all possible, always have some sort of secondary PRV that is NOT capable of being shut off any time you are pressurized.

If I were configuring your setup to achieve what you're attempting, I'd first get a 4" TC to 1.5" TC reducer and mount the PRV shown in the first picture and mount it on the 4" TC port on your fermenter. Leave it there ALL the time, except for cleaning. Seriously. That device is both a PRV and a vacuum breaker. It's not adjustable, so it can't be Murphy'd up. Make sure you buy one that has a release pressure that will open at a pressure less than your tank's rated maximum pressure. For instance, a 15 psig rated unitank will likely have a maximum rated (tested) 30 psig pressure. You never want to actually reach this pressure, but if you do you'll survive the episode. That's why you always want it in place. For a 15 psig normal operating tank, look for one that releases around 22-24 psi. They're not terribly accurate (that's why they shouldn't be used for spunding) but they're very reliable.

The vacuum breaking feature will also keep your tank from imploding. Pressure tanks can hold an amazing amount of positive pressure, but will fold like a cheap suit at amazingly low vacuum pressures. That device in Picture #1 protects you both ways from Mr. Murphy and any unintended ***ups on your part. Everybody makes mistakes from time to time. This devices keeps you from making one that could kill you. Never "valve" it, always use it. No exceptions.

The manifold in Picture #3 is a really neat accessory. I've been lusting after one for quite some time, but Santa didn't leave one in my stocking this year, so I guess I'll have to take matters into my own hands. The PRV in the manifold is supposed to release in the vicinity of 15 psig, and maybe it will if it doesn't clog with krausen. Don't bet your tank on it. It has no negative pressure relief. It's adequate as a secondary backup relief valve for positive pressure, but I wouldn't trust it for primary /singular protection. It does give you a quick and reliably dependable way to depressurize the tank however. The spunding valve in Picture #2 is an adequate, but not optimal, way to spund. But NOT at the beginning of fermentation. Yes, it is capable of releasing an overpressure, but the very fact that it is adjustable makes it unsafe to use in place of a PRV (or two). I have two of them and often use the with kegs, but only after having set and verified the pressure release point by measuring on a pressurized keg that has greater pressure than what I want set on the spunding valve. The keg also had a built-in PRV. It's also rated to 130 psig. (PRV releases well below that pressure).

If you intend to spund with the device in Picture #2 wait until the fermentation has reached high krausen and is subsiding, preferably when the wort is approximately 5 points from Final Gravity. But first cycle the PRV on the manifold to make sure it vents and hasn't gotten clogged with krausen. Krausening this way is pretty safe as long as you do these steps and wait until high krausen is subsiding. It's a great way to carbonate beer.

So, good to go, right? NO.

We never discussed the initial part of fermentation. You know, the part where the vast majority of CO2 is being generated and the risk of overpressure in your tank is the greatest. Here's two possible ways to get where you want to be, and they both involve a blowout line just like the one that came with your tank in the first place. The first way is to start with the ⅜" barb x 1.5" TC cap. Attach it to the 1.5" TC fitting on the top of the tank. Set a ⅜" silicone hose line on the end into a jar of sanitizer. Let fermentation happen. When you're SURE that high krausen has passed and the fermentation is slowing down, swap the blow-off line with the manifold on the tank-mounted 1.5" TC port. Closely (and I do mean closely) monitor the pressure to make sure the spunding valve is properly set and releases at your desired pressure.

Another way to skin this cat would be to mount a T pipe on the tank's top TC port and attach both the blow-off line and the manifold to it. Start fermentation with the blow-off line in place. When fermentation slows, swap the blow-off TC fitting with a 1.5" TC end cap. If you're quick, the ingress of oxygen will be minimal and will likely be consumed by the ongoing, but slowed, fermentation.

TL;DR. Bottom line: you NEED a dedicated PRV, unadjustable, not able to be isolated from either the tank or the outside, preferably with negative pressure relief capability, in use AT ALL TIMES! You need a dedicated blow-off line to vent the huge volume of CO2 being generated in the early stage of fermentation, that you can replace with a true spunding valve once fermentation begins to slow down.

Pressurized fluids can be enormously dangerous. Multiple pressure relief pathways are desirable. Pay close attention and take nothing for granted.

Spunding is a great way to carb beer naturally while saving money on CO2 tank refills and cutting a week out of your time between grain to glass. I'm not convinced specifically that fermentation under pressure has much net advantage on the homebrew scale except possibly for lagers. I've tried it a couple of times and really saw no direct benefit. Spunding on the other hand is very worthwhile and is the thing that makes pressurized unitanks and pressure capable fermenters worth having.