1.1 This specification covers crosslinked polyethylene (PEX) pipe that is outside diameter controlled in metric pipe sizes 16 mm to 100 mm and inch pipe sizes 3 in. to 54 in., made in nominal pipe dimension ratios, and pressure rated for water at three temperatures (see Appendix X1). Included are requirements and test methods for material, workmanship, dimensions, burst pressure, hydrostatic sustained pressure, excessive temperature-pressure, environmental stress cracking, stabilizer functionality, bent-pipe hydrostatic pressure, oxidative stability in potable chlorinated water, and degree of crosslinking. Requirements for pipe markings are also given. The pipe covered by this specification is intended for buried pressure piping applications (such as, industrial and general-purpose pipelines, potable water pipelines, fire – extinguishing pipelines). This specification also includes carbon black requirements for PEX pipe used for aboveground pressure piping applications.

1.2 The text of this specification references notes, footnotes, and appendixes, which provide explanatory material. These notes and footnotes (excluding those in tables and figures) shall not be considered as requirements of the specification.

1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.

Note 1: Metric sized (SI units) pipe should only be joined with corresponding metric-sized fittings and inch-sized pipe should only be joined with corresponding inch-sized fittings. Inch sized fittings should not be used for metric sized pipe, and metric sized fittings should not be used for inch-sized pipe.

1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.