How do Beerbelly bulkheads seal?

[shoobs]

I'm trying to sort out some bulkhead fittings for my new kettle and mash tun. I can't quite work out how the Beerbelly weldless bulkheads work:
http://shop.beerbelly.com.au/bulkhead-50mm.html

Are they just two locknuts, two washers, two gaskets and a long parallel threaded nipple? If yes, what stops leaks between the washer and locknut or leaks through the thread of the locknut?

Or is it actually a nipple with a flange? What is the point of the washer, then? Shouldn't the gasket be compressed between the flange and the wall of the vessel?

 

[shoobs]

Same goes for these:
http://www.fullpint.com.au/bulkhead-1-2-bsp-male-bsp-to-male-bsp/

What stops liquid running along the threads through the locknut and vessel wall? Are the o-rings supposed to compress so much that the squeeze into the threads and form a seal? Or do you just have to use heaps of thread tape and hope for the best?

 

[Cocko]

Thread tape, mate. Needed for all weldless fittings.

 

[barls]

unless beer belly have changed the design in the many years since i purchased.
its a fixed washer with a threaded section each end. you put a oring ether side and tighten till it doesn't leak. mines been in place for about 7 years no leaks.

 

[shoobs]

Thread tape, mate. Needed for all weldless fittings.

Mmm, even ones like this? http://www.fullpint.com.au/bulkhead-1-2-male-bsp-to-female-bsp/

To me, if you take the washer away, the seal will be formed by the o-ring compressing between the flange and the vessel wall. No thread tape needed (except for the fitting on the outside). Like this:

Relying on thread tape to make a seal between parallel threads is a bit dodgy.

 

[zeggie]

You still need thread tape

http://youtu.be/_Uqs9jw61VY?t=7m54s

 

[Cocko]

Mmm, even ones like this? http://www.fullpint.com.au/bulkhead-1-2-male-bsp-to-female-bsp/


Relying on thread tape to make a seal between parallel threads is a bit dodgy.

It is not dodgy mate, it is what thread tape is for.

 

[shoobs]

You still need thread tape

http://youtu.be/_Uqs9jw61VY?t=7m54s

Yep, that video explains my point perfectly. You're relying on the thread tape to give a seal between parallel threads, which isn't good practice. Proper bulkhead fittings shouldn't have a locknut on the inside, they should have a flange like this:

A gasket jammed between the flange and the vessel wall gives you a perfect seal on the inside without any thread tape.

It is not dodgy mate, it is what thread tape is for.

Not really. Thread tape is used for seals between male taper threads and female taper or parallel threads. Parallel to parallel threads aren't designed to seal using tape, they're designed to seal with a gasket or o-ring:

 

[zeggie]

Look at the video again. 8:24

water/wort can follow the threads to outside the kettle. Your O-ring isn't going to seal against the thread, only against the kettle wall.

Follow this vid when you install. http://youtu.be/iKKWLRu7jdg?t=5s

Good luck

 

[shoobs]

Look at the video again. 8:24

water/wort can follow the threads to outside the kettle. Your O-ring isn't going to seal against the thread, only against the kettle wall.

Follow this vid when you install. http://youtu.be/iKKWLRu7jdg?t=5s

Good luck

Yep, I get what you're saying. What I'm questioning is why the bulkheads are designed like that in the first place (and I'd like to know if the Beerbelly ones are actually made that way). To me it seems like a bad idea to rely on the thread tape to seal the locknut threads to the nipple threads. If the nipple was tapered it'd make more sense.

Ideally, bulkheads should be designed like this:


The flange and nipple are one piece, so there can't be leakage along the threads. The o-ring stops any liquid getting to the exterior threads.

 

[barls]

Yep, I get what you're saying. What I'm questioning is why the bulkheads are designed like that in the first place (and I'd like to know if the Beerbelly ones are actually made that way). To me it seems like a bad idea to rely on the thread tape to seal the locknut threads to the nipple threads. If the nipple was tapered it'd make more sense.

Ideally, bulkheads should be designed like this:

proper_bulkhead.jpg

The flange and nipple are one piece, so there can't be leakage along the threads. The o-ring stops any liquid getting to the exterior threads.

this pic is how mine are made

 

[djar007]

I would personally have a washer on the outside of your bulkhead. Especially as I pull mine apart often to clean.

 

[Cervantes]

I found it was very important not to over tighten.

Over tightening distorts the O Ring and then it doesn't seal.

 

[elcarter]

These are low pressure sealing applications, it's not rocket science.

If it leaks use thread tape.

If it seals you still should have used thread tape.

You'll pull it apart and use thread tape when it starts leaking with a double batch of your award winning beer.

More thought needs to be placed on correct hole dimensions and vessel sidewall condition.

I'm on team thread tape,

 

[shoobs]

I'm on team thread tape,

Haha, I can tell. I'm not advocating not using thread tape - it is necessary for all thread to thread seals.

I'm just questioning the sanity of using a straight nipple with locknuts on both sides as a bulkhead rather than a solid bulkhead like I drew. It seems that a lot of people have had bad experiences with weldless bulkheads leaking, and it is no wonder with a design like that.

 

[Crusty]

I used the Blichmann way to seal mine in the 150lt kettle.
I couldn't get it to seal any other way. This works perfectly with zero leaks & no thread tape except for the ball valve.

 

[shoobs]

this pic is how mine are made

Just a quick update.

On your advice, I went and bought 4 bulkheads. It looks like they don't make them like your ones any more. Here is a pic of what I got in the post:


Just a long nipple, two locknuts, two washers and some silicone seals that are too small for the nipple. The only way to stop liquid leaking along the locknut and nipple threads is to use a heap of thread tape on the parallel threads.
I'm going to return these and try and find another supplier of bulkheads with a solid flange.

 

[stux]

I got these ones.

The in-kettle flange+nipple is one piece, so the only leakage is *inside* the bore.

http://www.brewershardware.com/Weldless-Bulkhead-1-2-MPT-X-1-2-FPT.html

 

[Smokomark]

Just a quick update.

On your advice, I went and bought 4 bulkheads. It looks like they don't make them like your ones any more. Here is a pic of what I got in the post:

IMG_20150119_180158.jpg

Just a long nipple, two locknuts, two washers and some silicone seals that are too small for the nipple. The only way to stop liquid leaking along the locknut and nipple threads is to use a heap of thread tape on the parallel threads.
I'm going to return these and try and find another supplier of bulkheads with a solid flange.

Mate I'd go to a machine shop and get some custom made if I was you. Yes it will cost you a fair bit more $$$ but at least you will get what you want.

 

[shoobs]

I got these ones.

The in-kettle flange+nipple is one piece, so the only leakage is *inside* the bore.

http://www.brewershardware.com/Weldless-Bulkhead-1-2-MPT-X-1-2-FPT.html

Yep, exactly what I want. I'm struggling to find ones that are long enough (I have a thermopot with a 25mm thick wall) and are BSP. I'll join a BSP 1/2" to an NPT thread if I have to, but I'm trying to avoid it.