Attaching cornelius post to fermentor

[drtablet]

Hello,
I'm looking to attach a cornelius post (gas and liquid) to the top of a plastic fermentor.

For this I have my eye on a cornelius keg post that screws onto the top of a PET bottle.
Does anyone know of any fittings I can get that I can use to screw this onto that can be used to make a male coupling in a brew vessel.

This is an ebay link to the female corni post quick release that attaches to the top of a PET bottle.

http://www.ebay.com.au/itm/271434448309?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

Looks like the PET bottles use 3/4" threads called M-Type (as far as I can tell).
So need a way to seal a hole in a fermentor with a male version of this thread identical to the top of a PET bottle.

Hope I've made some sense here.
Suggestions very welcome.
Craig

 

[DJ_L3ThAL]

3/4" bulkhead type setup would most likely be easiest method. Not sure what M type thread is would have though it to be ISO/BSP

 

[Florian]

Maybe you could somehow seal the very top of a PET bottle to the fermenter lid?

 

[drtablet]

thanks guys.
I think sealing a PET bottle top to the top of the fermentor would be pretty tricky but yes it's worth thinking about if I can't find a bulkhead to fit.

The PET top thread is not BSP. The thread is much wider than BSP for sure.
I'm hoping M-Type is simple M12 (for 3/4") the standard metric threads of nuts and bolts, but the thread looks quite wide and tapered (I assume to allow a good seal to make make it air tight with such few turns.)
I've searched for a M12 bulkhead so will go down this road for now but if anyone knows for sure what thread PET bottles use and a compatible bulkhead that would be the perfect solution.
cheers

 

[Blind Dog]

Hello,
I'm looking to attach a cornelius post (gas and liquid) to the top of a plastic fermentor.

Why?

 

[TheWiggman]

I'm guessing as a blowoff tube?

drtablet, if you're going to install something like this I'd be concerned about the possibility of blowing up the fermeter if your seal is good. If this was put in place of the airlock and you decouple it for whatever reason while the yeast was still active you have a potential bomb.

This has me thinking though, a bulkhead through the top with a camlock or similar would make a very nice blowoff tube adapter. Might rattle through the spares box tonight...

ED: On topic: http://www.dresselbrew.com/Keg_Info.htm
19/32" thread for normal keg posts, why not look at one of them instead?

Otherwise, a water bottle on my desk has this thread: http://imajeenyus.com/mechanical/20120508_bottle_top_threads/pco1810.pdf
It appears beverage bottles have their own specific thread. NOT 3/4", closer to 28mm. Grab a ruler and see for yourself.

 

[Florian]

This has me thinking though, a bulkhead through the top with a camlock or similar would make a very nice blowoff tube adapter.

Not really if you think that all that yeast crap gets stuck in the poppet which is a pain to clean in those pet adapters.

I'm assuming the OP wants to do pressure transfers.

 

[keifer33]

These guys sell a bulkhead style post adaptor - http://www.brewmart.com.au/brewmart-shop/catalogue/?detail&ItemID=4154&SZIDX=0&CCODE=16447-GAS&QOH=0&CATID=246&CLN=1

 

[drtablet]

Hi,
Yes its for fermenting under pressure. I'd have a pressure release valve attached to a quick connect so to avoid blowing up.
I already do this i.e ferment/condition under pressure using a 19l corni keg.

What I want to do now is carry on the same technique but use a much larger vessel. Hence would like to use the same system and release valve but need a corni valve on the top (and liquid one also for closed transfer and sample drawing off)
Wiggman, yes I think using a 19/32" thread for normal keg posts would appear a better option if I can't find a bulkhead for the PET corni posts.
cheers so far
Craig

 

[Camo6]

Kegking do these too. Page 48 in their price list catalog. They do a spunding valve setup also but sounds like you've already got that sorted. No affiliation.

 

[Blind Dog]

Hi,
Yes its for fermenting under pressure. I'd have a pressure release valve attached to a quick connect so to avoid blowing up.
I already do this i.e ferment/condition under pressure using a 19l corni keg.

What I want to do now is carry on the same technique but use a much larger vessel.

A Corni keg is pressure rated, a plastic fermentor is not. At best the pressure will simply escape, at worst it won't and it'll burst/explode under the pressure.

Unless you do in fact have a pressure rated plastic fermenter?

 

[S.E]

Hi,
Yes its for fermenting under pressure. I'd have a pressure release valve attached to a quick connect so to avoid blowing up.
I already do this i.e ferment/condition under pressure using a 19l corni keg.

What I want to do now is carry on the same technique but use a much larger vessel. Hence would like to use the same system and release valve but need a corni valve on the top (and liquid one also for closed transfer and sample drawing off)
Wiggman, yes I think using a 19/32" thread for normal keg posts would appear a better option if I can't find a bulkhead for the PET corni posts.
cheers so far
Craig

You may have trouble getting the lid to seal the rubber rings often don’t seal very well on fermenters.

What size batch are you fermenting? You could use a 25L cube if it is big enough, they seal well and take a fair bit of pressure. I’ve pressure tested one to over 20 PSI.

Ive seen 50l kegs converted to fermenters with corny keg lids if you can get hold of one.

 

[TheWiggman]

Not really if you think that all that yeast crap gets stuck in the poppet which is a pain to clean in those pet adapters.

I said camlock. No poppets in a camlock. Hence why I suggested it and not the post OP was asking about.

drtablet, I still maintain not fermenting under pressure in a standard HDPE fermeter. There are pressure-rated plastic containers about but a standard Coopers type fermenter is not one of them. The lid would be the first thing to go I reckon.

 

[Florian]

I said camlock.

And so you did, completely missed that.

 

[drtablet]

Hello everyone.
First I'd like to say to everyone a big thanks for all the posts.
I really do appreciate everyones comments and feedback, everyones.

I'm using a 200l plastic conical from Rota Moulding.
Its food grade and several members of this forum have already used this type of container (100l at least) to ferment/condition under pressure as I plan on doing. I've already got it mounted in a fermenting fridge with STS.
see pic
http://i103.photobucket.com/albums/m128/craigtalbot72/Brew/20141130_132301b.jpg
cheers

 

[pilgrimspiss]

What kind of pressure are you building up? 5psi?. Interested in how much they can take.

Cheers
Matty

 

[drtablet]

Matty,
I know one guy doing pressure conditioning that uses around 5-7psi.
And apparently the lid and O ring can take 15psi, but I've yet to try it.

I'll be using 10psi or under I think.

http://aussiehomebrewer.com/topic/3628-plastic-conicals/page-9

Craig

 

[Tahoose]

The keg king weld less ball posts are probably the best option. But you can also get ball post fittings which screw on to the commercial style couplers. These are 1/2 bsp, so you could whack them straight onto a 1/2 bsp bulkhead fitting if you wanted aswell.