ASTM WK56095

    New Specification for Minimum Required Strength (MRS)-Rated Metric- and Inch-Sized Crosslinked Polyethylene (PEX) Gas Pipe

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    Developed by Subcommittee: F17.60 | Committee F17 | Contact Staff Manager


    1. Scope

    1.1 This specification covers crosslinked polyethylene (PEX) pipe that is outside diameter controlled in metric pipe sizes (DN 16 to 1000) and inch pipe sizes (NPS 3 to 54) and pressure rated using the minimum required strength (MRS) rating system. This specification is intended for PEX pipe made by various processes (PEX-a, PEX-b, PEX-c) as long as the PEX pipe made by that process meets all the requirements of this specification. If joined by electrofusion fittings, each type of PEX (PEX-a, PEX-b, PEX-c) needs to be individually qualified with a manufacturers electrofusion fittings, since electrofusion joining to PEX pipe made by different processes can result in varying joint integrity. Included are requirements and test methods for material, workmanship, ultraviolet (UV) stability, dimensions, hydrostatic sustained pressure, environmental stress cracking, stabilizer functionality, bent-pipe hydrostatic pressure, minimum operating temperature, and degree of crosslinking. Requirements for pipe markings are also given. The pipe covered by this specification is intended for buried gas pressure piping applications. 1.2 The text of this specification references notes, footnotes, and appendixes that provide explanatory material. These notes and footnotes (excluding those in tables and figures) should not be considered as requirements of the specification. 1.3 The pipe dimensions (outside diameter and wall thickness) in this specification are for both inch-sized (NPS) and metric-sized (DN) pipe. All other values stated in this specification are in SI units. 1.4 Fittings are not part of the scope for this specification. As discussed in the referenced documents at the end of this specification, it has been demonstrated that PEX-a pipe can be joined by the electrofusion method. If PEX-b or PEX-c pipe meets the requirements of this specification, the user should assure that the PEX pipe can be joined by the electrofusion method. Note 1--Fittings to be used with PEX pipe manufactured to this specification are in Specification F2829. Inch-sized fittings should not be used for metric-sized pipe, and metric-sized fittings should not be used for inch-sized pipe. 1.5 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.


    crosslinked polyethylene; MRS; CRS; design stress; PEX; gas distribution; natural gas

    The title and scope are in draft form and are under development within this ASTM Committee.

    Citing ASTM Standards
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    Work Item Status

    Date Initiated:

    Technical Contact:
    Eugene Palermo

    Draft Under Development