CFC Build Q - pipe/hose fittings

I'm about to purchase the copper for a CFC - inspired by Bobby M. I'm going to buy 100' of copper and 100' of PEX, build 4, sell 3.

Since I'm not just building for myself, and since I'm pretty young at this (3 batches total, just looking for DIY to keep myself busy), I don't want to cause undo headaches. I was wondering if there are any "common" fittings I should stick to.

Specifically, I was thinking of ending the water lines with 1/2" NPT male ends, and the wort lines with 3/8" NPT male ends. Should I just go with it, or should I re-think part of that? I like the idea of differing diameters indicating the line use, but if that will result in someone frankensteining a ball valve or something, I'd happily go the path of least resistance.

Thanks all.

JA

Just leave the ends as they are. Just have the copper tube sticking out the end. Let the end user adapt the fittings they need. Also I wouldn't use pex. Won't pex melt? There is going to be boiling water going through it. I used automotive heater hose and when im recirculating with boiling water to sanitize, the rubber gets soft and it's rated for over 250 degrees. I wouldn't trust pex at boiling temps.

Home Depot gave me the following (roughly):

PEX:
Maximum working pressure of 160 psi
Minimum working temperature of 32 degrees Fahrenheit and a maximum working temperature of 200 degrees Fahrenheit

Rubber Hose:
Commercial-grade hot-water rubber hose withstands water temperatures of up to 190 degrees Fahrenheit

As far as I'm concerned, if the PEX can stand similar temps as the rubber hose, I'm good.

So why PEX, just to get it out of the way quickly...

1) Cheaper - I can buy 100' of PEX cheaper than a 50' rubber hose.

2) More rigid - It's got a bit more structure, should protect the copper in there a bit more. This is what sold me on the idea - cost is one thing, but I want the equipment to last.

It will be harder to lay straight, but I have a system for that (famous last words), and it will be harder to coil, but I've got a couple ideas for that, too, that I'm going to have to play around with.

I wouldn't feel safe using pex. It's also thinner and will not take the abuse and Wear and tear rubber can withstand. The rubber hose I used is for heating systems in cars and trucks. It's meant to take pressure and withstand temps of close to 300 degrees. I guess I overbuilt it but didn't trust a standard garden hose at those temps. Pex is also going to be very hard to work with.

JRems said:

Pex is also going to be very hard to work with.

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YArther, did you ever build this and if so, how hard was PEX to work with?

Also, if you did build it, how well does it work? (estimated flow rates, temperatures in and out, etc... greatly appreciated).

I was also having a look at PEX for a DIY CFC and it was starting to look pretty good until I saw this last post...

-fafrd

I made a 25' CFC with PEX and 3/8 copper. It was way easy to get the copper into the PEX, and the hardware store had PEX fittings that adapted 3/4" PEX to 3/8" copper perfectly.

I was only able to get my CFC to a 20" diameter circle, but it fits perfectly in my brew rig. 4 batches of 20 to 22 gallons each through it so far and no issues.

FourSeasonAngler said:

I made a 25' CFC with PEX and 3/8 copper. It was way easy to get the copper into the PEX, and the hardware store had PEX fittings that adapted 3/4" PEX to 3/8" copper perfectly.

I was only able to get my CFC to a 20" diameter circle, but it fits perfectly in my brew rig. 4 batches of 20 to 22 gallons each through it so far and no issues.

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Thanks for the quick feedback, FourSeasonAngler. I'm not too concerned about a large diameter either, as long as it is easy to slip the PEX onto the tube - did you need to use soap or any other lubricant? Since tubing and hose sizing can be so confusing, do you mind to clarify ID and OD:

3/8" copper tubing means 0.5" OD and ~0.45 ID, right?

3/4" PEX means 7/8" OD and 3/4" ID, right?

Also, I'm probably going to use 1/2" OD stainless tubing rather than copper - would you see any concerns about using stainless tubing inside PEX? How long was your CFC, 25' or 50'? What is the flow rate you are getting through the coil for your 20-22 gallon batches (how long to get the full batch through)? Gravity or pumped?

One last question for you - the specs on PEX that I have found indicate that PEX is certified for potable hot water, but is only rated to 180 or 200 degrees F. I assume your are chilling right from flame-out and so hot wort in is close to 212 degrees - what is the hottest you are getting hot tap out and if it is exceeding the maximum PEX ratings, would you have any concerns about using the hot water effluent to brew another batch of beer?

thanks again,

-fafrd

PEX will tolerate higher temperatures for "emergency" use.

Well, since the wort is actually never in contact with the PEX outer wall I don't think you will have a problem. The copper is holding the hot wort and any water in contact with the PEX will already be cool by more than a few degrees by the time it exits your CFC at it's hottest.

I did not need any lubricant to get the tubing inside the PEX. The hard PEX walls are very slick and your tubing should glide right through. I do think though that you should round off or turn-in the leading edge of your tubing so that it does not score or scratch the inside walls of the PEX as you push your tubing though.

The stainless tubing could cause problems while coiling, but this is just speculation at best. I'm not familiar with the malleability of stainless vs. copper. Kinks in your stainless from over bending will cause flow issues, could harbor trub and/or bacteria, or even worse leak. I have heard that filling the tubing with water and sealing the ends eliminates kinks, but I can't vouch for that.

My flow rate is good, I usually give my wort a 30 minute whirlpool before I start chilling so my wort is usually down in the 170 to 180 range by the time I start draining. I come out of a 90 degree dip tube into a 1/2 ball valve on the side of my kettle and end up having the valve 1/2 to 3/4 open. I drain between 10 and 11 gallons in about 30 minutes to get to 65/66 degrees, maybe 40 if I'm trying to get down close to 60 degrees for cooler fermenting beers. I do live in N. IL so those times are with the 47F to 53F tap water we have in the winter time.

5 gallons of 180F wort to 65F in 15 minutes with around 50F water should be about right. I assume my summertime brews will take a bit longer since I have seen my tap water in the summer come out closer to 62F/63F.

This is very helpful, FourSeasonAngler - thanks.

I thinking about using the chiller as a HERMS coil as well (recirculating hot HLT liquor one way versus mash liquid the other way), which is why I have the concern about PEX and water temperature exceeding the rated maximum.

During the mash, HLT temp will never exceed 180 degrees (more likely 170 degrees) so I would not be worried during that phase.

But during wort boil, I was planning to sterilize the chiller by running boiling wort through the SS coil, and during that phase, the PEX could get heated up close to 212 (whether it is full of air or still water). From what I have read, these temperature ratings for PEX are at pressure, and since there will not be any pressure in the PEX if/when it exceeds 180/200F, I am not too concerned about the connections and the integrity of the tubing itself, but rather the possibility of any leaching that might be hazardous.

While chilling wort, the effluent cooling water will not be consumed, so no concern there, but if there is anything in the tube not safe for consumption it may get into the HLT liquor on the next brew session (hence my concern).

You raise a good point about cool-down during the whirlpool settling time - this means that during cooling, the PEX probably never gets to 200F (or even 180F). It would be during the sterilization/recirculating cycle that the maximum ratings might be exceeded - how do you sterilize? Do you recirculate through the chiller while whirlpooling?

Great suggesting about rounding off the leading edge of the stainless. The stainless comes in 24" coils, so I can either leave it at that diameter (I assume the PEX would have no problem being coiled to 24" D) or if 20" is the minimum diameter for a PEX coil, I have access to a recoiler that would allow me to get the stainless coil down to 20" - what is the diameter of your PEX chiller?

And in any case it is very good to know that threading the metal tubing into PEX is straightforward without requiring unnatural acts. It sounds like the hard sidewall of the PEX actually makes it easier than threading into rubber tubing.

thanks again,

-fafrd

I clean my CFC with a process that starts with hot water run through once as a debris rinse, then hot water with PBW gets an over night soak, and the last step is to rinse with clean hot water the next day. I sanitize before chilling with Star San. No need to re-circ wort, no need for pumps, it's all gravity fed.

I have a 22" deep brew rig (sculpture) and the PEX CFC coil is 4 or 5 rings that fit under my MLT strapped to the underside of the sculpture without sticking out the sides. I have a silicone hose that just slides on the copper tubing from the CFC and my kettle valve for the "in" side, and another silicone hose that just slides on the copper at the "out" side that has an inline thrumometer and from there fills my carboys.

I should also add that coiling PEX on it's own (without tubing inside) is a major PITA. Add the coil inside and it's even worse, almost to the point of being damn near impossible without some kind of mechanical assistance.

Coiling my CFC took the better part of 3 hours.

FourSeasonAngler said:

I sanitize before chilling with Star San. No need to re-circ wort, no need for pumps, it's all gravity fed.

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Well if I could avoid recirculation of boiling wort through the chillerr, that would go a long way towards easing my concern. I have never used Star San before - does it need to be rinsed out? Is it safe to get some into the wort? I assume you mush be using a pump to get the Star San into the chiller tube, right? Any more detail you could share on your sanitizing process prior to chilling would be greatly appreciated.

-fafrd

p.s. with all gravity fed I guess you don't need to worry about leaving wort behind in the chiller, right? I was planning to pump the wort through the CFC and that is another issue I am struggling with. How many feet of gravity do you have from your BK down to your fermenter?

FourSeasonAngler said:

I should also add that coiling PEX on it's own (without tubing inside) is a major PITA. Add the coil inside and it's even worse, almost to the point of being damn near impossible without some kind of mechanical assistance.

Coiling my CFC took the better part of 3 hours.

Click to expand...

Sounds like you straightened your PEX and your copper tubing prior to inserting the copper into the PEX and then coiled the complete double-tube assembly, is that right?

If so, I don't think that is going to work with stainless - I was planning to match coil sizes (at 24" or 20") and then 'screw' the PEX onto the stainless. I was planning to use 1/2" stainless tubing and 1" PEX, so I should have a bit more clearance than you did, but I will need to insert coiled SS into coiled PEX - any thoughts as to whether this would be possible or not?

thanks again for all your help,

-fafrd