Replacing DW - discovered 1/4" PEX under sink?

Discussion in 'Plumbing Forum, Professional & DIY Advice, Tips & ' started by Cross-Eyed Cat, Feb 26, 2013.

  1. Cross-Eyed Cat

    Cross-Eyed Cat New Member

    Messages:
    3
    Location:
    GA and NC
    Hi All,

    I'm awaiting delivery of a new dishwasher, and was looking to see what I would need to make the swap. Instructions for the new one call for a 3/8" OD supply line. When I looked under the sink, I found that coming up from the floor are what I believe to be 1/2" CPVC lines. Hot side is topped with a Brass Craft stop, which is then immediately topped with a brass tee that sends a 1/4" PEX straight up to the faucet, and another 1/4" PEX to the left for the DW. (Photo attached).

    2013-02-26_13-43-47_141.jpg

    Is 1/4" PEX normal for a kitchen sink faucet supply? Seems too small?

    Is there any easy way to tell what the size of the outlet side of the top is? If it is 3/8, then I presume I could get a 3/8 x 3/8 x 1/4 tee and leave the faucet at 1/4 while upsizing the DW line. But if that outlet is only 1/4, would I be stuck with having to replace the stop? THAT would make me nervous, as this is coming up from a slab and I DEFINITELY do not want to break anything near the concrete level, especially since the old DW worked fine with everything as-is ... so, maybe I'm just making unnecessary work?

    Any advice appreciated!

    Susan
  2. mtcummins

    mtcummins In the Trades

    Messages:
    380
    Location:
    Pittsburgh PA
    Looks like you have a tee with 2 3/8" compression fittings. The best thing to do, IMO, is remove both of these water lines and buy yourself the appropriate length braided stainless steel flex connectors. You can find them labeled in the home store for a dishwasher and for a faucet. Usually the only 2 variables will be the connection size to the shutoff (either 3/8" or 1/2", most, including yours from the look of it, are 3/8"), and the length of the line. If its labeled for a dishwasher, it should have the appropriate end connection or an adapter to make the connection to the d/w. The faucet end of those lines is standard size, any that's labeled for a faucet should work. Just don't get one of the "toilet" ones or something and you'll be fine.
  3. hhplumbing

    hhplumbing New Member

    Messages:
    13
    Location:
    Victoria, BC
    As mtcummins said, I would pick up a DW braided supply (we normally sell the brasscraft B1-72DW 6ft line). Now from that picture that really looks to be a 3/8" retro tee and if it is, all you need to do is take off the pex line going to the DW and thread on the braided supply by taking off the nut and metal sleeve.
  4. Cross-Eyed Cat

    Cross-Eyed Cat New Member

    Messages:
    3
    Location:
    GA and NC
    I know those look like they might be 3/8", but the PEX lines coming out of them have 1/4" printed on them, which is why I am thinking that they are 1/4" -- in which case, I can't attach a 3/8" flex, right?

    Thanks!
    Susan
  5. johnjh2o1

    johnjh2o1 Plumbing Contractor for 49 years

    Messages:
    1,142
    Location:
    South*East
    There 1/4" ID and 3/8" OD.
    John
  6. Cross-Eyed Cat

    Cross-Eyed Cat New Member

    Messages:
    3
    Location:
    GA and NC
    OH! Thank you so much!! A little ignorance goes a long way. :) That makes everything so much simpler. I would like to add a separate shutoff for the DW so I won't have to lose the hot water in the sink just to isolate the DW, but looks like I can do that right at the tee by adding a 3/8" straight 1/4-turn stop to the left.

    Susan
  7. johnjh2o1

    johnjh2o1 Plumbing Contractor for 49 years

    Messages:
    1,142
    Location:
    South*East
  8. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,480
    Location:
    Cave Creek, Arizona
    You can use a John Guess "slip connection" ball valve in the line. Just cut the hose and push it into both sides of the valve.
  9. hhplumbing

    hhplumbing New Member

    Messages:
    13
    Location:
    Victoria, BC
    What I would do is find the tee in the picture below and replace it with the tee you have installed. just make sure you get the one thats 3/8" x 3/8" x 3/8"

    [​IMG]
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