ASTM D-2737 (DR-PR) Based on Controlled Outside Diameter
This specification covers polyethylene pipe made in standard thermoplastic pipe dimension ratios and pressure rated for water. Pipe manufactured under this specification is based on a controlled outside diameter which is designed to match and mate with copper tube using copper tube size (CTS) compression couplings.
Pipe manufactured to this specification is described using a prefix-diameter ratio. The prefix for ASTM D-2737 is SDR.
The most common ratio under this specification is SDR-9. The definition of SDR (Standard Dimension Ratio) is the specific ratio of the average specified outside diameter to the minimum specified wall thickness.
SDR-9 service tubing is available in black, Super Service™ Blue and Reclaimed Water Purple.