AWWA Standard C900 2007 R2016

The pipe is primarily intended for use in transporting potable water in buried installations. The standard describes dimension ratios (DRs) 14, 18, and 25 for nominal pipe sizes ranging from 4 in. (100 mm) through 12 in. (300 mm). Pipe outside diameters (ODs) conform to those established for CI-equivalent ODs (CIOD). Pressure classes range from 165 psi (1,140 kPa) to 305 psi (2,100 kPa). Major changes made to the standard in this edition include the following: the factor of safety was revised from 2.5 to 2.0; the built-in surge allowance was eliminated; the pressure classes were revised from 100, 150, and 200 psi (690, 950, and 1,380 kPa) to 165, 235, and 305 psi (1,140, 1,620, and 2,100 kPa), respectively; treatment of surge pressures was expanded to include occasional (emergency) surge and recurring (cyclic) surge; and, Appendix B, Recurring (Cyclic) Surge – Figures and Design Example, was added.