Ball valve connected to 1/2" NPT compression fitting (Weldless)

[OH-Brew]

Hello, I'm just wondering if anyone has ever connected their ball valve on the outside of their kettle directly to a compression fitting with 1/2" Male NPT threads on the inside of the kettle? Basically not use the 1/2" nipple that is typically used with weldless fittings. I want to use compression fittings with 1/2" Male NPT threads on one side that compresses a 1/2" O.D. tube (for a dip tube) on the other side.

Everything I have found shows everyone always using the 1/2" NPT nipple (weldless fitting) to connect their ball valve, and then on the inside of the kettle they use something with female NPT threads (i.e. a collar or compression fitting with female threads).

Any thoughts on being able to get away with connecting the ball valve directly to the male threads on a 1/2" NPT compression fitting?

 

[Bigbeavk]

I did the something similar with mine. I used a 3/4" full port ball valve connected to the compression fitting NPT thread. Then I machined the chamfered shoulder of the compression fitting side so it had a good flat area to mate up to the outside of the kettle. Then I removed the ferrel and used the compression nut to tighten it up to the kettle. Never had any leaks in 2 years so far. I also used a step bit to get the kettle hole just the right size so the screw threads on the compression side screwed right into the kettle. If a leak ever develops you could just take it apart and clean it and or have someone weld it on. Make sure you attached it to your ball valve first and line it up before you tighten it up to the kettle. I'll post a pic when I get a chance for you.

 

[OH-Brew]

I did the something similar with mine. I used a 3/4" full port ball valve connected to the compression fitting NPT thread. Then I machined the chamfered shoulder of the compression fitting side so it had a good flat area to mate up to the outside of the kettle. Then I removed the ferrel and used the compression nut to tighten it up to the kettle. Never had any leaks in 2 years so far. I also used a step bit to get the kettle hole just the right size so the screw threads on the compression side screwed right into the kettle. If a leak ever develops you could just take it apart and clean it and or have someone weld it on. Make sure you attached it to your ball valve first and line it up before you tighten it up to the kettle. I'll post a pic when I get a chance for you.

I would love to see a picture of this (because honestly I'm having a hard time trying to picture it in my head). Thanks for the reply though!

 

[Epimetheus]

Machining back the compression fitting is a great idea. A vendor on this site has just such a custom-developed fitting. Chagirn, I forget the vendor.

I tried to use a street elbow through the wall directly to the ball valve. After adding a metal washer to squish the elastic washer, there were not enough threads.

 

[kal]

Basically not use the 1/2" nipple that is typically used with weldless fittings. I want to use compression fittings with 1/2" Male NPT threads on one side that compresses a 1/2" O.D. tube (for a dip tube) on the other side.

Just out of curiosity, why? Why the aversion to nipples?

When you say the "typical way" that many do it, do you mean like this?:

(This is how I did it for my 2 compression fittings in the HLT that connect to my HERMS coil).

Kal

 

[OH-Brew]

Machining back the compression fitting is a great idea. A vendor on this site has just such a custom-developed fitting. Chagirn, I forget the vendor.

I tried to use a street elbow through the wall directly to the ball valve. After adding a metal washer to squish the elastic washer, there were not enough threads.

Looking at my current setup (only single vessel at the moment) it appears that my valve doesn't go past the first few threads. So I don't know that I will have the same problem of not having enough threads. Maybe that is just this 1 particular ball valve though..I've read that with NPT consistency is lacking, so my next valve could thread on the same nipple twice as far.

 

[OH-Brew]

Just out of curiosity, why? Why the aversion to nipples?

When you say the "typical way" that many do it, do you mean like this?:

(This is how I did it for my 2 compression fittings in the HLT that connect to my HERMS coil).

Kal

Hi Kal, yes, that is exactly what I mean by the "typical way" I guess the main reason to avoid the nipples would be cost....I can get 5 of the 1/2" Male NPT to 1/2" tube for $35, or I can get 5 of the 1/2" female NPT to 1/2" tube for $70. I'm actually building a Kal inspired system with BCS instead of PID's but I'm not using Blichmanns so I'll need a total of 5 of these fittings. 3 dip tubes and then 2 for the herms coil. I'm really hoping to have this setup going by the end of January but its getting pricey... so I guess I'm just trying to cut back where I can without making drastic changes. Thanks you very much for all of the detailed info on your website! Its much appreciated.

 

[kal]

The nipples are $2.50 to $3 each. I can't imagine getting a custom machined back fitting can be done for less but you never know!

One thing to keep in mind too is that if you go with anything custom, it's something you can't easily replace in the future. I personally don't like relying on something that only one person somewhere sells. I'd rather go with 'standard' parts available all over the place.

The other issue is that the way that you describe as the "typical way" is tried and proven. 100's if not 1000's have done it that way so you know it'll work. If you decide to do something different from something that's been proven to work and it turns out that it doesn't work right and/or leaks and you need to replace it, it'll end up costing you more. So it's more risky.

I only say this because my experience has been that often when you try and cut corners to save money, it ends up costing you more. At the end of the day of course the choice is yours.

My 2 cents.

Kal

 

[Bigbeavk]

Just out of curiosity, why? Why the aversion to nipples?

When you say the "typical way" that many do it, do you mean like this?:

(This is how I did it for my 2 compression fittings in the HLT that connect to my HERMS coil).

Kal

This is close to what I have but since I only use mine for a boil kettle I do not need the compression fitting. Parts C,D and E are made from one part on mine. Some teflon tape om the thread will help seal it. This is the same set up I have on my cooler HLT and it works great. The key is not drilling the hole for it to big. Without the welding involved I can take mine apart like this for occasional cleaning if I want to.

 

[mrwizard0]

I did mine exactly the way you are askng. I used kal's setup minus removing the nipple and changing the compression fitting to a male version. I have no leaks at all. I understand they aren't that expensive, but it did save some money. With the overall cost of my ebuild, any little savings helped.

 

[Bobby_M]

I saw the same shortcoming in the multi-step system and had special compression + bulkhead fitting made. The initial application was for integrating the 5/8" OD diptube like this:

Then I started making them in 1/2" tube diameter for HERMS coils, etc...

These use a larger hex stock than a typical off the shelf male adapter so that the gasket is supported directly by the fitting. The threads are a mix of NPS and NPT.
One other thing to consider is that these don't require disassembly as often for cleaning because the only thing on the inside of the vessel is the hex and gasket. Some weldless designs allow sticky wort to get further into the cavity and don't stop until the exterior oring.

I understand what you mean about the prices adding up fast. Our 5/8" diptube assemblies based on this system are $36 each and then the 1/2" bulkhead/compression fittings are $26 each. You may be able to do it cheaper but only if you happen to catch a killer deal on Ebay surplus.

 

[CCBrewer]

Dam it bobby why do you tempt us like this?

I just dropped 2 Benji's and now your having me make a wish list....

 

[OH-Brew]

Thanks for all of the feedback everyone! I definitely have some thinking to do now. Its good to know at least 1 person has had success using a male compression fitting, but those fittings look really nice Bobby_M...decisions decisions....