I intend to use schedule 40 3" pvc pipe to run my pex from outside water heater, through slab, up into an interior wall. I will have sweeping 90 ells. Will 1" or 3/4" pex be able to make the sweeping 3" 90 degree turns without a problem? Never used pex before and I've made my mind up about putting it in conduit - I just need to know if I need 3" or 4".


  • 1
    test it! create a PVC sweeping corner and see if your pex pipe can easily be fished through it.
    – DA01
    Jan 20, 2016 at 16:22
  • I sleeved a lot of my PEX also when it went under the floor. I think this is well worth the effort and additional cost. (It was ¾" PEX in I think 2" conduit and that worked, though it was a little hard to pull.) Jan 18, 2019 at 20:23
  • Just got dinged from an inspector saying Pex cannot go through electrical conduit.
    – Tom Clark
    Jun 8, 2020 at 19:26

2 Answers 2


The minimum bending radius for 1" Pex (the larger of your sizes) is listed as 9 inches. A typical 3" PVC sweep ell will have somewhere between 24 and 36" of radius. The only issue, then, is whether you can pull it. That will depend on the number of bends, number of tubes, and length of the run.


1" pex will have no problem making it through 3". Put your fittings on after fishing the pipe through the pipe/walls.

  • Yeah just put a hole a few inches in on the PEX and put tie wire through it and pull it in like electrical cable. Soap it up good on the way in. It should go a long way if your strong enough.
    – ArchonOSX
    Jan 20, 2016 at 21:06

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