Community Forums

brulaz · 02-03-2018, 08:02 PM

The PEX tubing in my trailer says 1/4" on it, but I can't find that size anywhere online.

The smallest I can find is 3/8" (the O.D.?), which looks like the O.D. of my tubing.

So maybe the 1/4" is the I.D.?

And I would still use a 3/8" PEX tee?

Old-Biscuit · 02-03-2018, 10:01 PM

PEX plumbing used in RVs is 1/2" ID (OD is 0.625")

Some smaller OD tubing maybe used for sink faucet hookups....3/8" PEX would be ID (OD is 0.500")

3/8" is smallest size in PEX

brulaz · 02-04-2018, 06:17 AM

Thanks, and that makes sense. I have a couple of fittings left over from our previous trailer that are all labelled 1/2".

But these pipes are just under both sinks and are really small. They have knurled knobs on them to hand tighten to the base of the faucet. I don't have my calipers with me but using a ruler they sure look like 3/8" O.D. Which may mean the 1/4" label on them refers to the I.D.

But like you say, I've never seen PEX that small and can't find any on the internet.

I'll search some more and email ORV on Monday if necessary.

Dale & Mark Bruss · 02-04-2018, 06:25 AM

There is 1/4" OD tubing used in an RV but it is not PEX, which has a higher pressure rating. Just because tubing is flexible does not mean it is PEX. And there is rigid PEX too.

For instance, the feeds to the icemaker in the refrigerator and a filtered water tap on the countertop use 1/4" tubing. And there are fittings for 1/4" OD tubing.

brulaz · 02-04-2018, 09:48 AM

Quote:

Originally Posted by Dale & Mark Bruss

There is 1/4" OD tubing used in an RV but it is not PEX, which has a higher pressure rating. Just because tubing is flexible does not mean it is PEX. And there is rigid PEX too.

For instance, the feeds to the icemaker in the refrigerator and a filtered water tap on the countertop use 1/4" tubing. And there are fittings for 1/4" OD tubing.

Ahh, now we're getting closer.

Turns out, it is "Merflex PEX OT Refrigerator Water Supply Line Hook-Up"
with "One-piece formed or molded ends with captive brass nuts".

Otherwise, the website is not very informative:
Mercury Plastics, Inc | Plumbing Products | Water Supply Line Hook-Ups

ORV is/was using the stuff to feed
both hot/cold faucets in my trailer.

The label on mine also says: 1/4" CTS
which seems to be the inside diameter with 3/8" O.D.

Finding a T adapter to insert in this stuff looks to be almost impossible ...

EDIT: Or maybe these: https://www.lowes.com/pd/BrassCraft-...ting/50284231/

Rowdy Joe · 02-04-2018, 10:40 AM

The CTS means , copper tube size.

brulaz · 02-04-2018, 11:33 AM

Quote:

Originally Posted by Rowdy Joe

The CTS means , copper tube size.

Thanks for that.

And now I have done what I should have done at the beginning: I traced these thin PEX tubes back to the adapter where they plug into the standard, familiar, 1/2" I.D. PEX tubing that's used for all the main feeds.

It's not that far away, and I can insert standard T there without any issues.

Thanks to all for the help & info.