Making a HERMS coil..Questions regarding choice in metal tubing

[Br3wBee]

Hello, I'm new to the site so thanks in advance for any tips:

I'm planning to make my own HERMS coil and have seen people using both 1/2 in and 3/8 in metal tubing of copper and stainless. In shopping I have seen copper rated NSF but have not seen the same for stainless.

My assumptions currently are: That although copper is technically a better conductor than stainless the constant immersion in the boiling water would make the difference negligible. Also I assume that NSF grade copper (refrigerator grade) is necessary since utility grade could contain contaminates that I would not want entering my brew but that Stainless does not have multiple grades.

My questions are: Should I use 1/2 or 3/8 in tubing, is copper better than stainless for this task, do I need to find NSF grade stainless if stainless is the best choice, would I need NSF grade copper if I went with that option, and lastly for a 5 gal batch with a 8 gal Hot Liquor Tun what length tubing should I use (25 ft, because this is what I was thinking).

Thanks again for your help.

 

[insanim8er]

Man I'd do SS and just buy it:

http://www.stainlessbrewing.com/Coiled-to-customers-request-035-304304L-Coiled-Tubing_p_30.html

 

[Br3wBee]

Ok well thats the best price Ive seen on a herms coil I might just do that, at that price why not. Thanks a lot.

 

[insanim8er]

Ok well thats the best price Ive seen on a herms coil I might just do that, at that price why not. Thanks a lot.

Smart move... You'd end up spending more and possibly bending the tube. It's the one I've been eyeballing but I'm not ready to get it yet.

Id recommend not bending the ends and doing 90degree compressions.

 

[Br3wBee]

that was actually going to have to be my next question. what is the deal with these compression fittings how and what would I need for SS because I've used the nut and ring method for copper but brass would be to soft for stainless steel. what would you need to use?

 

[insanim8er]

http://www.stainlessbrewing.com/Compression-x-Male-Elbow-NPT_p_97.html

You would install a coupler at the top and bottom of the kettle and attach these inside then the coil would connect to the compression side.

I've been slowly piecing mine together, so I actually have a bunch of those compression fittings. I'd be willing to sell off a couple. I believe they're 1/2 to 1/2

 

[Br3wBee]

I looked at that link and it looks like all you do is slide the SS tubing in and tighten the nut on the compression side?

 

[insanim8er]

I looked at that link and it looks like all you do is slide the SS tubing in and tighten the nut on the compression side?

That's basically it. Inside there is a ferrul (kind of a flat funnel shape) that goes in towards the tube it then gets squeezed tight as you tighten the nut. This seals the tube.