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

Discussion in 'Vertical and Horizontal Loops' started by Douglas Nathe, Jul 13, 2018.

  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 Active 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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