HDPE pipe comparison for horizontal loops. SDR11 vs IDR11.5

Discussion in 'Vertical and Horizontal Loops' started by Douglas Nathe, Jul 13, 2018 at 8:22 AM.

  1. Douglas Nathe

    Douglas Nathe New Member

    The standard recommendation is 3/4" SDR11 HDPE 4710 pipe, I can find this all over with online suppliers.

    My local FW WEBB sells "Pipe 3/4" Black Polyethylene PE4710 Plain End" with an IDR of 11.5.

    What is the difference between SDR11 and IDR11.5?

    The pipe from FW Webb is about 10% cheaper than any SDR11 pipe I have found and would be great to avoid shipping.
  2. mtrentw

    mtrentw Member Industry Professional Forum Leader

    SDR vs. IDR. -
    SDR is the Outside Diameter of the pipe divided by wall thickness.
    IDR is inside diameter divided by wall thickness. So an 11.5 IDR is probably closer to a 13 or 14 SDR. Basically, it is a thinner pipe wall.

    Lower DR means higher pressure rating.

    That said, it may work fine. Caution on fittings and connections. I Believe most geothermal accessories are based on SDR.
  3. Douglas Nathe

    Douglas Nathe New Member

    Thank you for the Details. I figured they would be more comparable then what you said. In that case, I'll stick with the more common SDR11.
  4. docjenser

    docjenser Well-Known Member Industry Professional Forum Leader

    We tried to use SDR 13 in horizontal loops, but we went back to SDR11. SDR was kinking to easy.

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