Hi all,

Could I *directly* connect the female threading of this fitting:
[www.plumbingsupply.com]

...to this stainless fitting:
[www.homedepot.com]

...or this fitting (lead-free brass):
[www.homedepot.com]

...or both of those, stainless-to-brass?

Does there need to be any adapter for plastic-to-metal?

Put PTFE tape on, I assume?

Thanks!



Edited 8 times.

NO

the threads on the TEE are NOT tapered pipe thread (NPT)

==============================================

"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

1. There is NOT "female" threading on that tee
2. NONE of the "male" threads are designed for anything OTHER than the compression nut
3. The tee connections are ALL compression so you have to insert the tubing in to them.
4. What are you trying to do since the second and third pictures show completely different fittings?

Ok, thanks for the insights. I see what you're saying now.

So, say I have this:
1/2" N x 3/8" OD (1/4" Nom.) angle stop valve:
[www.plumbingsupply.com]

...and I want to couple it to one end of this 1/4" x 1/4" x 1/4" tee:
[www.plumbingsupply.com]

What kind of coupling hardware would I need?

My thoughts are getting 2x stainless steel male nipples (1/4" N x 3/8" Mips) to convert to NPT, then getting an NPT-based stainless steel (or brass?) female coupling.

But that seems like alot of hardware, no? Isn't there a more direct way?

Thanks for the help!


hj - I'm trying to connect up this system:
[i.imgur.com]



Edited 3 times.

you simply need a 3/8 x 3/8 x 1/4 tee - voila, DONE


jic: 3/8 run x 3/8 run x 1/4 bull/branch

==============================================

"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

A short piece of 3/8" tubing, a 3/8x 1/4 compression union and a short piece of 1/4" tubing. The angle stop and the tee are compression fittings and need tubing to connect to them. There are fittings available, that can connect to a compression fitting, but they're not a common item.

It is NOT the fittings I would use, but you need a short piece of 3/8" tubing to attach the tee to the valve.

For PolyB piping, can I use any kind of compression fitting, as long as it has a plastic ring? Also, should I use a tube stiffener?

Can I put stainless/brass fittings on plastic fittings? i.e. like this:
[www.plumbingsupply.com]

yes

==============================================

"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

One, almost positive, way to ensure a plastic fitting will crack is to screw a female plastic one on to ANY metal male thread.

bernabeu says yes. hj says no. plumbingsupply.com sells the combo directly... i'm confused...

3/8" pex or smaller uses a plastic ferrule and no insert sleeve. ½" and larger uses a brass ferrule, but a stainless steel sleeve.

Edited - for errors



Edited 2 times.

Ah, ok.

Where does this knowledge come from? Are there technical references I can look to for this?

Also, is it necessarily bad to use a brass ferrule on 3/8" PEX?

For example, my Brasscraft 1/4 turn valve includes a brass ferrule to connect to 3/8" PEX. As I understand, Brasscraft is a well-respected company, so I'm surprised they'd slack (or even be completely wrong) on included parts...

steve, what about this hardware for compression fittings on 3/8" PEX? Says it's compatible...
[www.plumbingsupply.com]



Edited 2 times.

Brasscraft catalog - [www.brasscraft.com]

Ah, thanks Steve!! Guess I was reading the Brasscraft valve tech specs wrong!

What about that hardware I linked to at the end? Do you think these are OK parts to use for a compression fitting (from plumbinbsupply.com):



That would hook onto a 1/2" NOM PB tube for cold + hot kitchen supply lines.



Edited 2 times.

(deleted - see above)



Edited 2 times.

I prefer using brass fittings instead of plastic, whenever I can.

I bought those plastic fittings because I thought something about them was special for PB tubing. Seems like all PB fittings are plastic...

How could I use a brass compression fitting on 1/2" NOM PB?



Edited 1 times.

One of the pictures you posted showed a conical rubber gasket in the threaded end. If so, then it is NOT depending on the tightness of the thread, so the female fitting will not be stressed, therefore it would work, (although I could think of many "better" ways to do it).

I have used that plastic acetal coupling that you're showing a picture of a number of times with 100% success. To me that's a "perfect" fitting for connecting p.b. to copper or cpvc.