Standard dimension ratio explained

Standard dimension ratio (SDR) is a method of rating a pipe's durability against pressure. The standard dimension ratio describes the correlation between the pipe dimension and the thickness of the pipe wall.^[1]

Common nominations are SDR11, SDR17, SDR26 and SDR35. Pipes with a lower SDR can withstand higher pressures.

SDR = (d _{o})/(s) d _{o} Pipe outside diameters Pipe wall thickness

Notes and References

1. Web site: SDR - Standard Dimension Ratio and S - Pipe Series.