HERMS coil in Keggle build question

[GJOCONNELL]

Trying to start laying out plans to do a HERMS coil in one of my keggles....want to take that efficiency to the next level using an SS Brewtech MT.

Having issues trying to source the best place to get the coil and most cost effective way to connect to the keggle.

I see the weldless fittings (compression) on bargain fittings and was wondering if that was the cheaptest route coupled with a 50 ft SS coil. Is there a pre-fab. version of the coil with connections built/installed already?

Already have two pumps, re-circ. mash arm from SS brewtech.

All advice is welcome.

 

[jcav]

I used a HERMS coil in my keggle and I bought this one from Stainless Brewing.http://www.stainlessbrewing.com/HERMS-10-Coil-with-2-bends-50-x-12-OD-Tubing-304_p_30.html
I used compression fittings and I ended up using an o-ring with the large ferrule and did not use the small ferrule, instead of the plastic ferrule, as this one eventually leaked when I tested it later. When I added one o-ring it sealed flawlessly and has never leaked since. You can check out page 4 of my build thread in my sig below to see the HERMS coil and how I installed it. Hope this helps...

John

 

[Bobby_M]

In my opinion, the most cost effective and solid way to install is my pull through compression fittings that you would silver solder in. Strong like a tank and extremely low profile. https://www.brewhardware.com/product_p/ptbulkcomp12.htm

Here's a pic of the inside with the coil installed:

If silver soldering is not your thing, we also have the best weldless bulkheads that already have a compression fitting built in. It's almost as low profile as the above, but there is a hex piece on the interior that backs up and captures the seals. https://www.brewhardware.com/product_p/truebulkhead12comp.htm Please don't confuse these with other compression bulkheads. They are pricey at $24 each, but they don't leak or wobble.

We also have precoiled 50' stainless HERMS. https://www.brewhardware.com/product_p/hermscoil.htm

 

[jcav]

Soldering is a good way to go as well. I just didn't want mine to be permanent yet as I was going to have tri clover fittings welded later to match the rest of my build. I can recommend those weldless bulkhead compression fittings from Bobby, as that is what I used. The only thing I did differently was use the nylon ferrule, which didn't work in my case, so use the metal ones that come with the bulkhead and you should be good to go.

John

 

[day_trippr]

fwiw, I also use Bobby's compression bulkheads with my 1/2" hex and the nylon bushings and bulkhead o-ring are still holding tight...

Cheers!

 

[GJOCONNELL]

so using the metal ferrule it is essentially permanent? I would prefer to be able to remove it if necessary.

Hmmm actually I think I might be better off converting one of the keggles to herms. How much torque is needed to make a solid connection?

 

[Bobby_M]

The permanency of metal ferrules are not what most people think. When initially attached to the tubing (a process called swaging), the thin metal ferrule compresses down on the tubing and usually cannot be removed. That does not mean that the tubing cannot be removed from the main body of the compression fitting. It just means that the thin ferrule stays on the tubing and traps the compression nut behind it.

The problem with stainless ferrules on stainless tubing is that it's all very rigid. A good seal requires a LOT of torque to swage the ferrule to the tubing and the tubing has to be flawlessly round and smooth. I don't recommend them for most applications in brewing. What's a LOT of torque. More than you probably feel comfortable applying. It's like locking the fitting into a bench vise and using a 20" long box wrench on the compression nut.

Nylon ferrules offer a good hold with a lot less torque and they are somewhat forgiving with slight defects in the OD of the tubing. Anyone that has trouble getting these to seal may have a significant out of round issue which is typical when trying to attach to tubing too close to a 90 degree bend. This is why we do all our HERMS coil bends on the far side of the helix so the run in into the fitting is straight and round.

Bobby

 

[crane]

Nylon ferrules offer a good hold with a lot less torque and they are somewhat forgiving with slight defects in the OD of the tubing. Anyone that has trouble getting these to seal may have a significant out of round issue which is typical when trying to attach to tubing too close to a 90 degree bend. This is why we do all our HERMS coil bends on the far side of the helix so the run in into the fitting is straight and round.

Bobby

This makes a lot of sense. I have a herms coil from stainlessbrewing.com and they bend the 90 on the near end, not the far end. I started with nylon ferrules, but they eventually leaked. Found out the hard way on a back to back brew day when both beers came in with unusually low gravity. I replaced them with silicone o-rings and they are holding up alright for now.

The other problem I have with the bends being so close to the end of the tube is that if I slide the compression nut on too far it gets stuck because if the tubing being more "out of round" the closer you get to the bend. In a keggle you don't have much room to work with and it's a huge PITA to get the coil installed. Additionally I had to grind out the ID of one of the compression nuts because the tubing was so "out of round" all the way up to the end of the tubing.