ASTM WK57078

    New Specification for MRS-Rated Metric- and Inch-Sized Cross-Linked Polyethylene (PEX) Pipe

    (What is a Work Item?)

    Developed by Subcommittee: F17.26 | Committee F17 | Contact Staff Manager


    1. Scope

    1.1 This specification covers cross-linked 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 MRS rating system. This specification is intended for PEX pipe made by various processes, as long as the PEX pipe made by that process meets all the requirements of this specification. 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, oxidative stability in potable chlorinated water, minimum operating temperature, degree of cross-linking, and hydrostatic burst pressure. Requirements for pipe markings are also given. The pipe covered by this specification is intended for pressure-piping applications such as, industrial and general purpose pipelines, potable water pipelines, fire-extinguishing pipelines, and chemical pipelines. It is not intended for gas gathering or gas distribution. 1.2 This specification also includes requirements for qualifying joints made using polyethylene electrofusion fittings and PEX pipe. NOTE 1--NPS fittings should not be used for DN sized pipe, and DN sized fittings should not be used for NPS pipe. 1.3 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 this specification. 1.4 Units--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 nonconformance with the standard. For consistency with ISO 9080, MRS values are only in MPa and degrees Centigrade for conversion to the pipe material designation code (for example, PEX pipe with an MRS of 8 MPa is called a PEX 80. 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.


    cross-linked polyethylene; MRS; CRS; design stress; PEX


    The scope is to develop a new ASTM standard for PEX pipes based on the MRS rating system as determined by Test Method ISO 9080. This PEX pipe is to be used in pressure-piping applications such as, industrial and general purpose pipelines, potable water pipelines, and fire-extinguishing pipelines. This new ASTM standard is very similar to ASTM F2788 except that it uses the MRS rating system.

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

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    Work Item Status

    Date Initiated:

    Technical Contact:
    Eugene Palermo


    F17 (19-06)

    Withdrawn From Balloting


    F17 (20-04)

    Ballot Item Approved as F3288-2020 and Pending Publication