Had to disconnect my dishwasher for a kitchen project, my existing supply line is in bad shape, bought one of those Dishwasher kits that uses PEX (see https://www.homedepot.com/p/SharkBite-1-2-in-Brass-Push-to-Connect-Dishwasher-Installation-Kit-25568/302360425)

Do I need to remove my existing shutoff valve and replace it with the one in the PEX kit or can I use PEX with any valve? If I can't, is there a way to tell if the valve supports PEX just by looking at it?


edit - here's a picture of the existing valve (dishwasher supply not connected)

enter image description here

  • 1
    Direct pex to any valve probably not. There are adapters/couplings for almost any pex to other stuff.
    – crip659
    Oct 14, 2023 at 14:04
  • @crip659 - is there a particular name or type of these adapters? do you have a link for a sample one? not sure what to search for Oct 14, 2023 at 14:06
  • 1
    Not the question but ... now that you've sunk the money into this new valve, and since it's so easy to install, if your old valve is more than 10 years old and you're in there on your knees with tools anyway .... you should replace it. Because the next time you need to fiddle with it in another ten years, the old valve won't turn.
    – jay613
    Oct 14, 2023 at 14:13
  • I usually just go and see what fits. If I guess it would be pex to "type" of old valve connection type(threaded, compression, solder).
    – crip659
    Oct 14, 2023 at 14:20

1 Answer 1


You cannot connect PEX to "any" shutoff valve but you don't really mean that. :)

Your valve is pretty old and it makes sense to swap it out now. But your new valve feeds both the dishwasher and the cold tap. I don't know if you want to keep expanding the scope of this project! Your best bet is to just return the kit and buy a longer metal braided dishwasher hose that fits your situation.

If you want to use the new kit with the old valve, I think it contains all the bits you need but you might need this: Your old valve has a 3/8 inch compression outlet. To put PEX on it you might need a nylon ferrule and a sleeve to adapt PEX to a copper compression fitting. You can get them in pairs. The sleeve prevents the PEX from crushing under compression. Search youtube for how to use these.

enter image description here

Your kit includes a "3/8 compression to PEX adapter" that maybe could do the same thing. But I'm not sure, and I think maybe that's meant to go at the dishwasher end of the hose if your dishwasher has a compression fitting already.

  • added a picture in the original post - eventually I would like to use the new valve (since its new hey) but I just need to get this stuff installed and did not want to spend more time on this right now, I picked up the PEX vs a metal hose because my dishwasher is not right next to the sink, and when I tried to use a metal line it was too short and kept kinking and I couldn't get it to make a curve Oct 14, 2023 at 14:24
  • You can buy a longer metal hose. Still cheaper (by half) and better than this kit. But I think this kit has what you need. You might need a couple of extra bits, I'll add to the answer.
    – jay613
    Oct 14, 2023 at 14:48
  • so, would this old (in the picture) valve be ok for now? Eventually (few months realistically) I would get around to installing the new valve that came with PEX the kit Oct 14, 2023 at 14:52
  • The old valve, @ConfusedWithPex, may do well for the next 20 years. Or, it may fail to turn then next time you try. Hence the recommendation to replace it now. You've got to put some valve in there, the existing one will not connect to PEX without some adapters (a PEX crimp fitting to whatever type of connector is on the old valve), so why bother to do that when you already have a PEX crimp valve in your kit? Just crimp the new valve on and screw the rest of the plumbing to the other end of that!
    – FreeMan
    Oct 14, 2023 at 14:56
  • @Freeman I agree (obviously) but OTOH if I never used PEX before I would want to practice in the garage before putting my first one in a confined space with less than an inch of stub to work with!
    – jay613
    Oct 14, 2023 at 14:57

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