another 3/8" pex manifold idea

archibald tuttle

OK, since the industry has all but abandoned my favorite size, i had an epiphany the other day. you can still get adapters to compression connect 3/8" pex to various manifolds but there aren't any available i'm aware of for 3/8" crimp.

So i'm wondering about the over/under on expanding 3/8" pex to drop onto 1/2" crimp fitting. i don't recall ever seeing standard expansion type tool heads in 3/8 and i don't believe they would have standardly expanded enough to make that difference but I am fantasizing (you fantasize about weird stuff when you hit 60) some kind of heated swage and die unit that could reliably expand the end of 3/8" pex for that purpose.

for now i guess its back to my same old 1/2" manifolds and then 1/2x3/8" crimp coupling in line. not the end of the world really ,but just thinkin outloud here on a sunday morning.

Danny Scully

So what exactly are you looking for, they make everything lol.

SuperJ

3/8" seems like the perfect size to feed panel rads, maybe not for longer infloor zones though. I wish it was more popular.

hot_rod

A basic copper tube manifold? Sioux chief has all sorts of pre built or just copper tube branch type. SupplyHouse.com shows all sorts of choice.

Add 1/2 X 3/8 pex adapter, or Dahl mini ball valve with 3./8 pex barb.

Caleffi offers 3/8 compression fittings for the brass manifolds if you want top line with all the components.

rick in Alaska

I just turned 60 myself, and am not fantasizing about weird stuff. Just getting more cranky.
I am assuming you are trying to get from 3/8 pex to 1/2 pex. I don't know if any one makes an expansion adapter, but you definitely can get a 3/8 expansion tool. I have one in my Uponor manual expansion kit. At least I am almost positive of it.
One of the first radiant jobs I did was with a local radiant "innovator" here, where we put radiant into a church. This was all done with 3/8 tube. It works great. Very easy to pull also.
The more I write this the more I think I should look into it for my next job as it is so much easier. Just got to watch the loops.
Anyway, check with Uponor for a reducer coupling.
Rick

archibald tuttle

getting a reducing coupling is no problem, it's just extra fitting and two crimps at every manifold outlet to crimp on a short piece of 1/2" and then change. i do it all the time but then on sunday mornings I get on heating help and **** about it.

Danny Scully, you are damn good internet sleuth if you found a 3/8" crimp manifold. It is a nice theory that they make everything, which they do, unless they don't.

much kevetching on the part of manufacturers that there isn't enough business in 3/8 so no manifolds, limited fittings, etc. try getting 3/8" pex angle or straight stop. veiga has got 'em for twice the frieght for a 1/2". And i didn't even see any 3/8" barrier tubing on the big pex websites, in fact i didn't see any 3/8 tubing on one.

there are manifolds that take a compession nut where you can get the compression nut that goes from 1/2" down to 3/8" just like with flare tubing. e.g. these nuts (albeit in flare they are tracking OD rather than ID but you get the point):

http://www.supplyhouse.com/Jones-Stephens-F40-014-641FS-86-1-2-x-3-8-Brass-Short-Forged-Flare-Nut

This nut, like the compression manifold nuts allows you to make a nice large bell flare with an offset flaring tool and attach 3/8" tubing to a 1/2" fitting.

So I'm imagining doing the same thing for crimp fittings, opening the 3/8" pex far enough to fit onto a 1/2" crimp. problem of no 1/2" manifolds solved! Rick, is there a part number on that 3/8 uponor expander. i'm not kicking those right up. if you still have it try opening a throwaway piece of 3/8 enough to fit over a 1/2" crimp. my guess is it probably isn't meant to open that far but given then difference in specs between the crimp and expansion style fittings who knows.

And maybe even if you could make the head open that extra distance I wonder if just cold expanding might be a little much on the material, although the 3/8 and 1/2 sizes are pretty close together . . . but i'll try anything once or with a hair dryer or heat gun.

but I am totally with everyone who would prefer to work with 3/8 over 1/2 which is why i keep looking for solutions.

hot_rod

this is the compression fitting I referred to, it is a standard, common R-20 manifold nut, fits TRV also. A standard catalog item, and it should fit most ant brand of manifold.

Sioux Chief offer 27 million versions of copper manifolds, I know they still build 3/8", but it may not be on the shelf.

1/2" copper branch manifold are still common, just sweat whatever end you want on it.

archibald tuttle

hot rod, i'll tell 'em you said to dig deeper. its just those copper manifolds with the ball valves already on and crimp connections are sweet. so fast and cost effective. i don't care if they are dusty if i could get one with a 3/8 crimp but i fear not. who do you know over there whose chain i can yank . . . thanks

Gordy

If you have a Menards in the area they sell souix chief 3/8 branch copper manifolds with shut off all day long.

hot_rod

pexheat.com has several choices of 3/8 copper manifolds

rick in Alaska

If you are using Wirsbo manifolds with R20 connections, you can use the adapter part number Q4020375 to connect your 3/8 tube to it.
The Wirsbo expander head is a number Q6310375
Rick

archibald tuttle

Hot Rod - thanks for the link although those don't seem to be matriculated into the market. Although we don't discuss price lets just say that the opportunity cost of using adapters for the 1/2" manifolds doesn't justify the list price and without much dissemination in the market you can't really figure out what the market price is.

Gordy, sioux chief has conveniently just discontinued their 3/8" manifolds, see, e.g.:

https://www.supplyhouse.com/Sioux-Chief-671X0690-3-4-PEX-x-Spin-Closed-Manifold-3-8-PEX-Outlets-6-Outlets

although they still do have some stock. i'm trying to find out if it can be bought for a reasonable price. unfortunatley they do not concede that they ever made a 3/8" manifold with a valve other than custom. now maybe menards is a big enough player and had demand and had a bunch made custom. If you or anyone who has a menards nearby observes that they really have 3/8" branch manifolds with ball valves in stock I need to see if I could get them to ship me some.

sioux chief will make anything you want if you order 25 of them. i am currently getting a quote for 3/8" valved branch manifolds. I'm looking at 6 port although i'm negotiable if there are folks out there who want to share an order. 25 is a little more than i would like to own . . . and without discussing specfics of price, obviously my interest is how much of a premium compared to the market for standard manifolds one has to pay for this custom approach, because it simply may not outweigh the current opportunity cost of simply crimping a short piece of 1/2" onto a valved branch manifold and then crimping a 1/2x3/8" adapter.

finally, rick, WIRSBO will not admit how wide their 3/8" die goes and of course deny any warranty for my secret plan to expand 3/8" pipe to go on F1807 half inch connection which i still think might be doable. Any chance you can crank your 3/8" out to the max and let me know what diameter you can expand to?

In yet another paean to the industry's attempt to strand 3/8" , that number is a good number but the biggest supply on the internet is out of stock!

thanks for all the thoughts. keep those cards and letters coming.

Larry Weingarten

Hi, Here's more to chew on. http://www.rems.de/expanding-extracting/hand-tube-extractor/rems-hurrican-h.aspx This tool makes it easy to make your own manifolds. Then silver solder in a stub of tube, or? See photo of a manifold I made going to 3/8" PEX.

Yours, Larry

hot_rod

i always kept a stock of CustomCuts on hand. Basically a copper manifold, either 3/4 or 1" with 1/2' copper stub outs. This allowed me to build or customize whatever I needed.

Add valves, different size pex adapters, zone valves.

I also have a T-Drill to build whatever I need, although the factory build versions always look better

Here are some seeds and stems I have left over.

I think you can still find the blank copper stub outs to build your own?

archibald tuttle

larry, nice tool but the steps just push the nicety beyond labor hours practicality unless you are really looking for onsite hard builds. and then obviously you can stagger frequency and mix different sizes, etc. do you think the silver soldered branches would be able to sustain the weight of a small circulator?

hot rod, absolutely, the straight copper branch units and solder your own are a possibility although i'm not sure how easy it is to come up with a 1/2" sweat by 3/8" pex ball valve just on its own. and i'm using these regularly and its just plain easier to crimp the 1/2" pex and then the 1/2 x 3/8 adapter inline. obviously it would be nice to skip that step but building up my own manifold is going in the wrong direction for regular work. i can't get that retentive about what the final product looks like.

but rick, i found the spec for the F1960 fitting and the OD of the 3/8" expansion fitting is literally within a 100th of the 1/2" F1807. So i think i have a system to try out in some of my own stuff with attention to how it is located so I'm not in a world of hurt over failure, but the expansion is about the same. in theory i could crimp over it but the wall thickness would be slightly lower than standard half inch because of the expansion. so the crimp would not be really speced for the application. although i'm betting that expanding and crimping are likely to last as long as i'll be around to blame! can't recommend it of course for trade use but I think it wouldn't be that hard to make a crimp ring to match the circumstance if the corrugations on the 1/2" F1807 don't have sufficient relief in order for the rebounding 3/8" to grip as well as on a F1807 1/2" style body as the correctly sized F1960 3/8".

hot_rod

http://www.dahlvalve.com/products/mini-ball-valves/images/521-13-PX2.jpg

It is on the Dahl website, google that number for a supplier

archibald tuttle

no one seems to be offering it on the net that i can find, but that is the valve. the search did bring up lowes in canada but it is not that valve, its a dahl standard sweat valve. when i have a chance i'll try calling Dahl and see if they can find a reseller they have sold some to, esp. if my 1/2x3/8 expansion hack doesn't seem to work too well. thanks,

hot_rod

Dahl builds to order also. You may need to buy a box

Looks like they offer expansion type fittings also.

Or just buy any ball valve and sweat any pex fitting into it

Watts Radiant used to do special orders here in Missouri. I think that equipment went to Sioux Chief when Watts closed

At some point a SS, brass, or composite manifold with Caleffi 3/8 fittings may be cheaper and readily available most anywhere. It would give you zoning options also.

SuperJ

Neat, they have a tool to build your own custom valves:
http://www.dahlvalve.com/build-your-own-valve-summary.php